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Project performance WBX build

73K views 89 replies 10 participants last post by  iain ambrose 
#1 · (Edited)
I'm going to mirror this thread as I'm finding myself spending more time on VZI these days....

Though I would share my new engine build currently in progress.
Sadly the current engine has been having some issues of late with a noisy valve train.
I changed the hydro lifters with no improvement and having measured lift across the valves it appears one lobe is going flat :(
Fortunately I have been planning another build as a spare.

I already had a 2.1 MV short block purchased for ÂŁ75.
It was sold as seized and this turned out to be pistons stuck in the bores.
After a strip down and clean up I checked over all the parts.



The cam was worn on the lobes so that was binned.
All the pistons cleaned up nice but will also be binned as they are the low compression MV type.
The crank looked fine but just needed a polish.

All the parts where dropped off with Jim @ the engine shop for a good check over and crank polish.
He also has a second hand set of DJ High compression pistons kicking around.
2 of the original liners where toast where they had seized so only the other two where honed.
Jim now sells uk made replacement camshafts ranging from stock to several performance versions.
The existing cam i'm running was sourced in the USA and is a CB Performance unit.
It's spec was:

Duration 270 degrees
Lift @ cam .298

I decided on Jim's fast road cam with the following spec:

Duration 290 degrees
Lift @ cam .289


Looks like a nice cam and I will confirm this later.
Anyone who builds these engines will tell you how the cost's escalate compared to a type 1 engine.
Head gasket kit ÂŁ120 :eek:

A set of piston rings ÂŁ55 (twice the price of a T1)

Main bearings and big ends come in at ÂŁ65.

That said Jim only sells the top quality parts.

A quick comparison between the MV and DJ pistons.


You can see where all the extra compression is made in the dishes.
 
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#2 · (Edited)
Currently I am missing many engine parts and although I could swop them over from the current engine I would rather build this engine as a completely separate unit.
The only parts coming over from the existing build are the heads and valve train as i've already invested time in porting them plus they retail at over ÂŁ300 a piece.
The main missing parts that I need are:

Flywheel.
Clutch assembly.
Pulley wheel.
Oil Pump.

Currently I run a stock 1.9 setup for the flywheel and clutch.
This is a 215mm unit and has worked well, but it's only really designed to handle 80hp rather than the 120hp currently running through it.
The stock 2.1 setup is 228mm and won't fit a T1 gearbox without some serious grinding work.
Getting good stock flywheels is tough these days so you can now buy new units made in China that are QA'd in the states via AA Performance.
In addition to stock sizes there are some 200mm units and also lightened units.
Personally i'm dubious of anything made outside of a vw factory and after some research the horror stories start to emerge regarding these flywheels.
Some have bolted them up only to find they don't fit perfectly central making them an expensive paperweight.
As I understand AA Performance have now solved this but working for a company that imports from China I know they will take every opportunity to cut corners.
I just don't want the hassle and worry about this.

Lucky for me I found the holy grail of vw t25 flywheels - a type 4 200mm NOS unit.

Also purchased was a matching 200mm stage 2 Kennedy pressure plate and a needle bearing for the center.



This units are factory balanced but I plan to have this plus the flywheel, crank and pulley wheel properly balanced.

To run a wbx engine with a type 1 gearbox you have to solve a minor issue with the shaft support.
On a type1 engine you have a central gland nut fitted with a needle bearing inside.
On a type 25 engine you have a longer gearbox central shaft that sits nicely inside the crank which has a needle bearing.
To get round this issue you need to fit a needle bearing inside the flywheel.


A couple of washers with a bolt presses it in nicely.


Next is to start checking components before the build.
 
#3 · (Edited)
With the last engine i'm ashamed to say that I simply fitted the camshaft without checking it properly.
It's certain to say that a camshaft should not have flat lobes after 30k especially as i'm a bit OCD with servicing.
This time I plan to check and confirm all the parts used and also blue print where possible to hopefully produce a quality engine build.
I started with the camshaft and bearings.

First thing to check is the cam thrust bearing.



Looking at the manual it states up to 6 thou gap is acceptable but I want to be looking at around 1 thou.
Straight away we have a issue:(
I looks like the bearing splays when fitted into the case as it runs nicely on it's own in the camshaft.
A quick flat sand on the thrust side should help.


Nope, it's gone from no clearance straight to 6 thou:(
Looking at the thrust surface it's uneven where I have sanded so it's in the bin.
These are mahle units so not impressed.
T25 engines run a single thrust stock but i've decided to order a set of double thrust and see how they fit.

Next, check the cam lift:


The two exhausts come in at 267 and 269. (1 % variance).
The two inlets are both 283.
https://i.imgur.com/smqSTj9.jpg[/IMG]
One inlet has a slight +- 1 thou variance on the lobe bottom, the others all look fine.
The potential issue with having an uneven lobe bottom is that it affects the hydro lifter as it maintains a zero gap.
As the valve returns to the closed position any variance in the cam lobe bottom will result in unwanted lift.
I believe this is one of the issues with my current cam as a rolling road test indicated a valve not fully seating.

I'll be checking that lobe again.
 
#4 · (Edited)
Next is the oil pump.

The stock T25 engine runs a 26mm pump comparable to a late style type 1 unit.
As with a type 1 when running an aftermarket cam and wheel you have to use an early style pump to allow clearance for the wheel bolts.
If you research vw oil pumps it highlights some interesting issues with the aftermarket pumps.

Firstly is the fit in the case.
An original pump will have a tight fit inside the case, aftermarket pumps all have a noticeable loose fit which is not a good thing.
The more the oil thins under operation the more is able to squeeze around the pump body rather than around your engine meaning right when you need the oil pressure the most it's dropping.
A solution to this is to cut an o-ring groove into the pump body to prevent leakage and it's something i'm still considering.

Also, aftermarket pumps come with an aluminum cover rather than a steel one.
A steel cover reduces pump gear wear and the subsequent pressure loss.

I made a 50% improvement in oil pressure on my existing engine by swapping to a steel cover and blue printing it.
The same process has been done for this build.


I used a shadek 30mm HD oil pump as it's a good quality start point.
The original pump cover was cleaned up and then using a flat surface progressively sanded through various grades until a mirror finish.
The shakek body with gears undergoes a similar process to ensure it's perfectly flat.
Next I opened up the oil outlet to be the same diameter as the case.
It might be that a type 1 case is smaller to match this pump but I want an smooth uninterrupted flow.
Found the right size drill bit.

After a clean up with a dremel.

Some suggest to radius the outlet hole inside the pump but for this application it's not really required.
All ready to install.


So, that's everything up to date.

Next jobs are getting the case properly cleaned and also paint it having already spent hours prepping it.
 
#5 ·
So, did a bit more research regarding cams.
Lucky for me there are some real engine builders who share knowledge
It's hard to believe we where able to live pre internet lol.

Anyways the general consensus is that the bottom of the lobes MUST me exactly round with +- 1 thou being the upper limit.
Running solid lifters is not so much a problem but more an issue of excess noise from the extra clearance on the lobe.
I thought it best to go back and double check the readings as 1 thou is a very small reading to check accurately.
It looks like there must have been some play in the gauge mount as the bottoms now look perfectly round.
Well i'm happy to say this cam looks great but I just need to check for any run out on the cam wheel.

Yesterday I secured access to a donor engine for parts which should provide most of what I need.
Hopefully a couple of liners will be good also.

Once I have the pulley wheel I need to find someone to balance it.

First choice was John Mayer up in the Scottish Isles but I suspect the courier costs would be more than the actual machine work.
I've spoken to James Calvert a number of times and he also seems a good choice, so i'll give him a call.

One other thing that's bothering me are the conrods.
They all cleaned up nice but as a known weakness in wbx engines I need to consider options.
The stock units run two types of bolt (stretch and non stretch).
Early engines appear to use the same bolt as the t1, but the later engines went over to stretch.
On my current build I reused a set of early non stretch as the manual states the stretch ones should always be replaced.
It's common practice to reuse the stretch bolts when rebuilding but leaving out the final 90 degree 'stretch' turn stated in the manual.
I think this would be fine for a stock engine but I would like to feel comfortable seeing the rev counter hit 6k on occasion.
You can get new stretch bolts but at close to 100 for a set you are already quickly moving into the aftermarket price range.

A t25 crank shares the same big end spec as a t1 (hence it's use in T1 engines) although the main bearing layout differs.
Sadly the small ends are a larger diameter on t25's though.
This does mean you can run t1 conrods giving you a good selection of options if you are prepared to machine the small ends accordingly.

James Calvert told me he sells conrods to any spec so i'll be speaking to him for some options I think.
 
#6 · (Edited)
Today the replacement camshaft bearings arrived.
They are Silverline made in Mexico and I have heard some good things about them.


Side by side with the Meyle one (Left).

You can see where some sanding has highlighted the low spot on the outer edge.
You will also note the lack of a locating tab on the Meyle unit.

The width comes in dead on 28mm so once the case is back from cleaning i'll trial fit.
Also purchased 5 genuine flywheel bolts as these are allen heads.
I've used standard bolt heads previously and there are all sorts of clearance issues that I could do without.


I'll be ordering a decent set of scales tomorrow as I need to check the piston weights.
Not looking forward to taking weight off pistons should it be necessary.
 
#7 · (Edited)
Yesterday I phoned James @ Stateside for a little chat about my build options.
Perhaps it would have been wiser to start with this phone call
As with many things on the internet (bloke down the pub) you can't always take things on face value, so it was good to talk to someone who clearly knows his stuff.

It seems the oem flywheel I have is actually cast not forged and a little tapping with a spanner confirms this.
This is not really a huge problem but it does mean lightening is not a option.
He does a forged lightened flywheel for ÂŁ190 so I plan to return the oem flywheel in favor of a forged unit.

I was hoping with this engine to have a wider rev range up to around 6k.
James can supply a set of recon vw units, balanced with new little ends and new bolts.
Uprated bolts on stock rods are limited and not really in my price range for what I want.
Alternatively he does a full set of H beams, again balanced and with arp bolts.
Cost wise i'm looking at ÂŁ145 for the refurbs or ÂŁ360 for the H beams.
It would be nice to uprate to the H beams but in reality this engine will be in a street car with no clutch dumping or sustained high revs.

He also offers a 4 dowel option on the flywheel/crank as extra insurance against unexpected detachment but again it's not really going to be necessary IMO.

So, one flywheel, set of refurbed rods and a dynamic balance seems to be the correct choice.

Got the engine case back from a chemical clean but it still has varnish in places that won't come off.
This weekend I'll be checking over the new cam bearings and hoping for a better result than last time :)
 
#8 · (Edited)
Last night I sorted out the cam thrusts.
Because I decided to use twin thrust bearings there was the issue of the locating tang on the second one.
The case only has a tang on one side so either you file off the tang on the bearing or cut a new locating groove in the case.
I chose the later as it seemed a better idea.
Out with a file and after some careful work the bearing fits nice and snug.

Once again the thrust bearings where splaying out so more sanding was required.
Finally I managed to get the end float to just over 1 thou, which will do fine.

The cam bolts have been slightly filed down to give a touch more clearance and I need to check again with the pump body in place and the bolts are torqued up.
Further to this I want to close the case and make sure both the cam end float is the same and also that the bearings don't distort.
 
#9 · (Edited)
Been busy today checking over things.

Firstly I found a bunch of photo's from the clean up so I thought I would post first.

Engine as picked up.

One of the best cranks vw made imo, good for 400hp (4 times it's original application :lol:).

Showing where it needed polishing, probably from sitting for so long outdoors.


I bought gallons of vinegar for the clean up process, the place smelt like a chip shop for days.


Does a great job of removing all the rust and grime.


Had to soak the oil pickup in thinners as the glazing was terrible after years of burning oil passing through it!
From

To
 
#10 · (Edited)
To check the cam end float the wheel was first bolted up.
Various torque settings are suggested ranging from 14 - 25 pound foot:rolleyes:
I went with 18 as suggested by an engine builder on shoptalk called 'tencentlife' who I know is particularly knowledgeable on all things wbx.
Lock Tight was added for extra peace of mind.

Before closing up the case a quick check to see if there are any pump clearance issues.
First problem is the studs are too short being set for a 24mm pump, so they where removed, cleaned, lock tightened and left with more thread.

With that done everything was bolted up and is all good.
Took the pump body out and closed the case with four of the main nuts to check the endfloat.
Happy to say it's just over 1 thou and the cam spins nicely with no issues.
With the case apart again I've checked the main bearings fit the case saddles and that the oil feeds line up nicely.
Gotta love wbx engines, still stock size main bearings after probably 100k dragging a van around :lol:
 
#11 · (Edited)
Well my weighing scales finally turned up.
The results are going to be a problem:rolleyes:

Looks like one piston is from another set as it's over 3 grams lighter than the rest.
All pistons are stamped Mahle +94V13 but this one light one also shows A021 where the rest are A011.
There are no signs this piston has been previously lightened.
Trying to find 3.5 grams to remove is going to be tough so I think a trip to the engine shop in the hope of finding a more suitable one would be wiser.
I'll have no trouble matching the remaining three and quite frankly it's hardly even worth doing.

Popped over to Jim's today and spent the best part of an hour removing a set of dj pistons.
To my surprise they were all wildly different with over 4 grams difference.
Annoyingly none of them improved on my current set.
Jim advised I remove the weight from the wrist pins, specifically to open out the ends tapering in and leaving the center untouched.
Fortunately not too much had to be removed but it took ages to do with a little dremel:crazy:

The target weight for the piston plus pin was 593.7 grams and although the scales should be accurate to 0.1 of a gram it was fluctuating, so I settled on 593.7 +- 0.1 grams.

Considering the original variation was 3.8 grams I would say this is an improvement:D

Whilst at Jim's I solved another problem.

The later 2.1 engines run a oil/water cooler system that sits between the filter and case and is designed to accelerate the oil temp build up and also to cool it.
In truth it's pretty useless as a cooler as the water would be 80-90 degrees anyway.
To run this system you need to operate with the later style cooling pipework and water pump, but as this presents clearance issues with the bulk head it's not a viable option.

To get round this issue and also improve the oil cooling a mocal sandwich plate is fitted allowing a cooler to be remotely placed but this requires an early style filter stud for the adapter to bolt up to.


Later style on the left with the extra length for the original cooler to fit, early simple filter spin on the right. (Note the subtle removal method of vice grips and a hammer).
Jim kindly removed it from a spare engine and it will be fitted to my case.

The engine pulley wheel will be posted this weekend so I should be in a position to arrange balancing with James and push on with building the short block.
I have returned the flywheel and also the clutch plate as I plan to use a stage 1 as advised by James.
 
#12 · (Edited)
Things are progressing, although a bit slowly.
The project has been held up waiting for a refund on the returned parts and also with a purchase of a porsche boxster sport.
Thanks to a friend a pulley wheel arrived and having spent 3 days in the vinegar pot and then primed came up ok.

There was a fair amount of rust but it will do the job fine.
Once the balancing is done it will get properly painted.
I was unsure on what colour to paint the case and liked the idea of gloss black but as it's going to get scratched silver seemed a more sensible choice.
The case has had many hours of sanding and dremel work to prepare and with some paint on looked pretty good.



I used Simoniz engine enamel as it's designed for aluminum engines and requires no primer.


This week I should be contacting Jim at stateside to sort out balancing and parts.
 
#13 · (Edited)
Hooray, things are moving again :)
Last weekend I popped over to the parents and spend a couple of hours draining all fluids from the beetle in prep for removing everything.
I want to stick to the engine rebuild in this thread but I will mention that the gearbox is also being removed and needs repair.
From the pictures you can see the gearbox oil literally pissing out of the boots despite all efforts to stop it.
It's my fault for using some expensive thin oil in an attempt to reduce the 4th gear whine.
Anyway, back to the engine rebuild.

No chance of an aircooled 4 bolts and you're done here:lol:
Plenty of extra pipes to remove, oil cooler, water, fuel but having no fan housing makes removing the bolts a breeze.

Engine out and ready for parts stripping.
I was originally only after the heads and all the bolt on bits but decided to pull the liners as well as these are low mileage.
The cordless impact gun made light work of removing the head bolts.


Top tip if your planning on replacing the head gaskets on your t25.

If you are unlucky and the liners are stuck to the heads you will have to remove the pistons to get the rings back in.
Removing the pistons for a wbx engine is a nightmare as you have to 'pull' the wrist pins out through the water jacket holes.
9 times out of 10 the bastards are stuck solid and rigging some kind of puller with long studs is your only option.
A quicker way is to remove the liner leaving the piston in place and then with a 14mm socket, universal joint, extension and breaker bar undo the conrod bolts.
You can just squeeze through past the piston and reach the nuts!
I used a magnetic pickup to unscrew the last few threads to prevent them from falling inside the case.
Fish out the conrod top shell and ensure the bearing shells are kept in the correct order.
Once the piston/conrod is out simply remove the wrist pin in a vice, put the conrod back and re-torque.
It's a good opportunity to check the big end shells whilst you're there and it may be wise to invest in a new set of bolts/nuts.

Having removed all the pistons and conrod's I confirmed the camshaft as the problem.

It's difficult to see but the whole lobe is galled and the edge is oddly shaped.
The hydro lifters don't sit square to the cam but are offset to induce rotation much like head valves and rockers to reduce wear.
Pulled the lifter for this lobe and the damage is clear.

Having got all I wanted this engine is consigned to the shed storage box possibly never to re-appear.


Another topic that frequently comes up with water cooled conversions is the potential damage caused by galvanic corrosion.
To summarize, it's a process where two dissimilar metals connected by a fluid and also electrically (common earth or touching) create a process similar to a battery.
The upshot is that one metal corrodes (aluminum in this case) as the electrochemical process takes place.
There is much debate about whether you can use copper, or stainless safely and if the right coolant can stop the process.

Here are my results done over 6 years of use.

I use stainless pipe work, not copper.
The pipes are not fully insulated from the car's bodywork.
The engine heads were new when fitted.
VW G12 coolant has always been used in 50% concentration mixed with distilled water and is changed every 3 years.

Here are the notorious head surface where the rubber gasket is fitted and fails.


Both heads are spotless with the only corrosion being where the head is exposed to the elements.

Anyway, got to clean everything up and decide what to do with the heads.
For sure there will be a 3 angle valve job and at least one new valve guide, plus a few valve stems have been damaged due to the cam problems.
I also want to spend a bit more time doing port work as there is hp to be gained in this area for sure.
Plenty still to do.
 
#14 · (Edited)
Today's job, porting :crazy:

In addition to port work these heads are going to need several guides replacing, likely due to a poor geometry setup from the previous build.
I also want to look at lightened retainers as the stock units are way too heavy.

Had today off work so spent some time researching head porting.
Porting is an art that requires much practice, but that said some basic port work is well within your average person's skill range (That means me:lol:)
The obvious things to do are matching your manifold to head and remove any casting marks from the ports.
I have already done the manifold matching previously so I start with casting marks.




These AMC wbx heads come with pretty good ports as stock but there is still room for improvement.
Along with casting marks there are uneven parts down the port that where smoothed over.
Importantly, I also blended the ports where they meet the seats as you don't want to create any unnecessary turbulence.
Clearly improvements have been made over the T1 head with the location of the valve guides.
Unlike T1 heads the ports are already optimised size wise to the valves, so unless larger ones are fitted you may well reduce the air speed by opening them out.
The other worry is that the water galleries are pretty close to the ports so you run the risk of grinding through and junking the heads.
Won't be doing that then!



Came out pretty good, but still need a little smoothing here and there to complete.
Moving onto the head chamber there where a few things to sort out.
The combustion chamber is pretty good from stock but it looks like you could extend it to meet the outer edges where the liner sits.
Looking at the pistons they have shaped chambers so I suspect they will match the head chamber, I therefore decided not to make any changes here.
Once any casting marks where removed I moved onto blending the seat edges.

You can see the black exhaust port on the left and the huge lip created by how far the seat is pressed in.
On the right I have ground the chamber level to the seat.
This should help prevent turbulence when the valve initially lifts.

I will leave the exhaust seats alone as they run much hotter and need the extra metal plus the flow won't be affected so badly.
Care was taken to avoid catching the seat sealing surface but they will be reground as part of the 3 angle valve job.

Pretty happy so far but much more smoothing required.
Having spent 3 hours doing this I can now see why a set of ported heads cost so much to buy!
 
#15 · (Edited)
More work today.
First job was to look at why this engine keeps blowing o-rings on the liners.
Unlike a T1 engine its critical that there are no combustion leaks between the head and liners.
To that end vw added 2 new parts to the gasket set to prevent this from happening.
First is a compression ring that sits between the head and liner.
Second is an o-ring that sits around the liner tops.
The compression ring gets crushed when torquing the heads making an airtight seal.
The o-ring prevents the coolant from traveling right up to the liner tops and boiling into gas.
One of the heads keeps burning through the o-rings, so previously I have had the chamber surfaces machined to remove any unevenness (You can see the surface flycut marks).
As this is still happening I decided to remove any residual ridges left as can be seen in the picture.
It's also important to have a smooth surface where the o-ring sits.

First thought was to use valve grinding paste but the ridges where pretty high.
Attempt one using sandpaper.


Nope, too much friction to turn, so plan B.




Much better, both the compression ring and o-ring areas are definitely smoother.

Whilst doing this I noticed that the liner was not a snug fit in this head and a quick compare with the other head confirmed a difference.
The head bores are 1/2 a mm larger on this head, which might explain why is has been so problematical.
No doubt a little material was removed with the sanding but not 1/2 a mm!
I popped an o-ring on the liner and placed in the head and discovered it still moved around:(
Put the same liner in the other head and it's a tight fit.
This would certainly have allow water passed the o-rings.

I have a plan.
There is actually another o-ring fitted to each liner at the bottom to seal the liner from the case innards.
It's a little larger, so i figured it's worth trying and fitted it on the liner top.
Luckily it works providing a snug fit, so I must remember to use them on this head when fitting.

Next I started on the exhaust ports.
These looked tricky as the port angles are much more acute, especially under the seats.

You can see the port quickly drops away leaving a sharp bend to navigate.
I have actually taken back the seat bottom in places as there was no aluminum behind to make the transition.
There is also a bump near the manifold end that I'm scared to smooth as it corresponds to a head stud hole passing through the head.
Ultrasonic depth gauge required to do this so definitely one for a pro.

You will also notice the soot outline where the gasket sits indicating that the port opening is too small.
Before diving in here I need to grab the exhaust header to confirm it matches the gasket size.

This had better be worth all this effort:lol:
 
#16 · (Edited)
This week has seen plenty of porting so won't bore you with that.

More research has been done regarding carb's, specifically air flow.
My current engine runs dellorto 40's which have been fantastic but for one issue, top end power.
There is so much low down torque it pulls like a golf tdi, but once the revs hit 5k the power drops off the cliff.
Realistically a set of 44's would move the power band up nicely but trying to source some at a sensible price is just not happening.
The other option is to change the venturi sizes to achieve the same thing.

My carbs run 34mm as per their original application but looking at this graph it starts to explain why the power drops off.

A 2.1 engine with 34mm venturi reaches peak power around 5500rpm.
The 36mm are the largest size for this carb and these push things to around 6000 rpm, which should liven things up.
So, purchased a set from eurocarb.

Old vs new


The original ones look die-cast, the new ones are spun aluminum.
Fitting them is a breeze requiring a quick removal of the top, remove the auxiliary venturi and accelerator jets and the venturi just pulls out.

With one set fitted I notice a lip which when compared the original was much larger.
Some filing and sanding on the lip improved the taper so that it won't introduce undue air turbulence.


Today was spent removing the gearbox from the bug ready for repair.
I spoke to Jim at stateside and have arranged for machine work later in september so for now the main engine build is on hold.
I will be focusing on completing the port work and getting the gearbox done and back in.

Lastly, I bagged a bargain on ebay today, brand new bare AMC head for ÂŁ92 including delivery (They are ÂŁ325 new with valves and springs!)
I am going to use this to replace the head with the oversize bores and sealing issues despite the prospect of doing all the port work again:lol:
Ah well, keeps me out of trouble.
 
#17 · (Edited)
Result! The head was first listed for ÂŁ140, I was tempted but let it run.
When it was relisted for ÂŁ80 + ÂŁ12 postage it was too good to pass up and having bid the last 30 seconds were the worst!
It arrived today.

I checked the guides with valves and they are nice and tight.
This later revision head does look a little improved over my current ones.
The inlet seat is more flush with the chamber but the bowls still look pretty awful.

The exhaust is even worse, check out the lip on the side!

Basically it's start again for this head:rolleyes:

Several hours have been spent working on the first manifold.
For the last build I had two options regarding manifolds.
I could have taken T1 manifold with welded bases and ported them out to match the rectangle wbx ports, but this would have taken ages to do.
Luckily CSP in German did a wbx style manifold with the correct port shapes for a sensible price.
The only downsides were the short squat runners required to fit under the T25 engine lid and the massive top inlet holes.

The venturi for comparison purposes is 40mm o/d.
I'm guessing this manifold is more suited to 48's or greater unless this oversize diameter improves flow somehow?
Originally I did port match these to the heads but badly using hand files, also leaving all the horrible casting marks inside.
This time I started by using some gaskets and paint to highlight the correct port shapes.

Due to the squatness of these manifolds it's limiting how much shaping can be done due to the risk of grinding through, especially where it meets the head.
The original castings prevent me from removing all the low spots as it's getting to the point where there is not enough meat around the port to seal properly.

There are some more casting marks to remove but i'm waiting on some more sanding belts for the dremel to finish them off.

The woman downstairs must love me right now, grrrrrrrrrind :lol:
 
#18 · (Edited)
Done with the inlet manifolds.


This weekend I should be able to pickup the gearbox once the driveshafts are removed and then get it over to Jim at TES.
I'll be taking the heads for some discussion about performance increases beyond a 3 angle valve job as i'm keen to extract every bit of HP I can.
There is certainly room for bigger valves but also possible flow improvement reworking the guides for instance.

I've made some decisions, I'm going with solid tappets.
Crawling around with feeler gauges every 6000 miles, looking forward to that again
I'm sure James can suggest a suitable cam for the build that will offer what I need.
This also means the rods will have to be uprated.
James made some interesting suggestions including aftermarket pistons in T1 spec to match the rods he supplies.
The idea is perfectly sound, but it's moving beyond my comfort zone.

I've been speaking to an experienced wbx builder stateside who offers a T1 aftermarket rod machined to accept 24mm pins.
Cost wise it's good, but of course shipping and taxes will likely double the price
With the right combo of parts i'm expecting a substantial HP increase.

Mocked up the finished pipe work.
It's pretty tight over the oil pump, but that's normal.
 
#19 · (Edited)
Today I contemplated changing the oil pressure sender setup.
There are two stock pressure switches, one below the pushrod's and one next to the oil filter.
The issue is shortage of space and the sender won't fit in either place without adapters.
Currently I have used a small piece of brake pipe with a selection of adapters that allows the sender to connect up to the oil filter hole and route round next to the sump bottom.
What I would like to do is to eliminate the pipe if possible.
This is where things go off tangent as during the mock up of parts I fitted the alternator to get the belt in place.
Having cleaned and painted everything else the alternator looked a mess, so I stripped it for painting.
Lucky for me I have very recently fitted new bearings so everything came apart easily.

New bearings already fitted.


I was rushed to get it all back on the car last time but now I need to address the worn parts.
The copper is pretty ridged and although working the regulator pickups are nearing the end.

Heritage do a replacement made by Meyle which at ÂŁ10 is worth trying.
I have smoothed out the ridges on the copper with sandpaper but it could really do with a lathe cut.
After plenty of sanding the aluminum body and cooling fan are ready for paint.
 
#21 · (Edited)
Nothing much to post but lot's happening behind the scenes.
James Calvert has sourced suitable rods from the states and these will be Scat I beams which he will then machine to take the required 24mm pins.
The supplied bolts will be chucked for some genuine arp bolts, so this sorts the weak point that was preventing any possible revs above 6k.
JC suggested a web 86a grind cam for my requirement of street use only, mid range torque for normal driving but a red line around 6500rpm.
The other limit was .500' max valve lift as any modifications required to gain clearances gets expensive fast.
WBX's have a fixed deck height as the water jackets also seal against the head, meaning you cannot use spacers under the barrels like a t1 engine.
In order to gain deck height you would have to shave the piston tops or start looking at alternative conrod/piston combos.
I'm not made of money and the cost of this build is rapidly heading towards 2k anyway :lol:
This cam matched with 1.4 rockers lands perfectly just under .500' but their use will depend on spring requirements which I will discuss later.
Lifters remains undecided between T4 solids or gutted and spaced T25 units, the later having both better oiling and less weight, but as I have an almost complete set of new T25 lifters i'll probably go with them.
The modification requires removing the internal piston and replacing with a suitable length tube that fits snugly under the snap rings which is apparently something Jim at TES used to do and may still have parts for.
JC is trying to source some German quality valves as stainless is proving difficult to find due to the 9mm stem.

And now to my mistake and the consequences:rolleyes:

During the port work I noticed some small bumps in the inlet chamber which appeared to serve no purpose and where duly smoothed out.

Turns out this area is pretty close to the valve spring seats and by doing this I will no longer be able to machine the seats down for fear of breaking through.
The other unexpected thing is that according to someone who races these engines they actually improve air flow due to the rolling effect created prior to hitting the bottom of the port turn.
Luckily machining should not be required as an option is using Berg retainers which increase the valve gap by sitting further up the stems.
The upshot may mean 1.4 lifters won't have any suitable springs, but I will leave this to the experience of JC.
Push rod's also remains undecided between JC's hd aluminum ones and stock.
The reason aluminum was used in T1 engines over steel was to match expansions as things got hot retaining your valve gap.
On a T25 wbx engine steel was used as it provided the extra required strength for dual valve springs and the raised rev limit.
Expansion is less of a problem on a wbx engine as the temps are so much better regulated, so you would not expect any tapping when using solid lifters on a hot engine.
The down side of the steel push rod's is of course weight but I think cost may be the deciding factor.
In anticipation of setting valve geometry I thought I would make an adjustable push rod out of an old used one.

Just needed to tap the holes and cut down a suitable bolt.

Had the tap in the tool box, so it cost nothing :)

Build wise i'm looking at receiving parts for the bottom end mid december so until then i'm focusing on the gearbox replacement and replacing all the suspension bushes whilst it's all apart.

The replacement alternator bushes arrived.



Despite being made in Germany they lack the quality of the original and were difficult to fit due to the holes not aligning perfectly:rolleyes:
 
#22 · (Edited)
A little more progress.
I'm still waiting for the main engine parts from JC but I suspect it will be next year now.
In the mean time I've been preparing what I can.
First up is the carb linkage setup.
This has been a pain in the ass since day one as it's not ideal for this engine layout.
I've been through 2 sets of bar mounts ends having worn them down to the point of engine running issues.
Part of the problem is that the bar is at such an odd angle.
The solution is to fit a CSP bell crank which will also free up room around the air filter.

Once it arrives there may be some tweaking required as it's a T1 style and I need to clear both the alternator and cooling hoses.

Second job involves the lifters as i've decided to modify my existing hydro lifters rather than go solid T4's.
Having discussed at length various options with a chap on shoptalk i'm going with his suggestion.
Basically all that needs doing is replacing the bottom spring with a solid sleeve, so I purchased a suitable steel rod that's very close to the bore diameter which I can cut down.

This is a hydro lifter with all it's components.



A hydro lifter works by filling the bottom area under the main piston with oil taking up any slack in the drive train.
There is a little ball bearing at the bottom of the piston that allows oil to pass though as required.
The lifter can adjust just under 5mm of gap so this will be the required sleeve depth.
You must retain the existing piston setup as it regulates the oil flow to the pushrod.


Each sleeve is cut and then required sanding to get as close to 4.7mm with the basic tools at my disposal :(

First hydro is back together with the retainer nice and snug to ensure everything stays put.

I'm debating whether to purchase a set of later style circlips as i'm concerned the current retainers won't hold up to 6k + revs.

Just got 7 more to cut, file, sand, measure, sand, file, measure........
 
#23 · (Edited)
The bell crank arrived and as expected it's not a direct fit :rolleyes:
On the wbx engine the top case has more meat where the studs fit.
This means the crank mount won't fit, so I made a bracket to relocate things.

I also had to replace the supplied mount stud with a longer suitable bolt and lock nut to stop the mount twisting back during operation.
Unfortunately the mount is not central now meaning the rods create uneven carb linkage movement, so I will be adding a spacer on the bracket.
This will mean the support bolt will then sit over the case webbing, so more mods required here also.
Nothing is ever easy with this engine :lol:
 
#24 · (Edited)
Road trip today to pickup parts from JC.
The crank has been balanced and polished.

Trust me, it's done, but I will leave it sealed up until ready for the initial build check.
The Scat rods have been machined and honed for 24mm pins.


Also they have been re-balanced and fitted with genuine arp 2000 bolts.
Thought I would weigh them for a comparison to stock:

Stock unit blows the scales as they max out over 660 grams, so total 671 grams when weighed in bits.


Scat comes in at 554.7 grams so that's 116 grams lighter or nearly 18% lighter!

I went for the lightened 200mm T4 flywheel combined with a 1700 lb Kennedy pressure plate and Diakin friction plate.

The flywheel has been balanced and marked to indicate component positions when assembled.


These flywheel's come pre drilled for extra dowel pins but won't be required for this build.
JC went through some more Cam / lifter combo's but the limiting factor of 500' max lift only left the original web 86a matched to 1.4's option.
This is actually a good choice anyway as a lower lobe height is better for the valve train but it does add considerable cost when including a replacement set of 1.4 rockers for my 1.2's.
Lifter wise I'm still torn between my converted hydro lifters and a set of JC's lightweight T4 units.
JC's view was that a T25 lifter had a much higher chance of wiping a lobe based on his experiences.
Luckily I don't have to make this decision yet until the valve geometry needs to be set.

This brings things to the last hurdle, valves.
JC has had no luck sourcing a quality set, so i'm going to have to try myself.
It does look like custom made may be my only alternative.
I'm keen to find out what the wbx racers use as this would seem a good place to start, so will be posting on STF and emailing a couple of wbx builders.
 
#25 · (Edited)
Slow progress but things are happening.

The heads have been completed by JC.
After much searching I ended up buying a new set of TRW valves only to find out that Manley offer an affordable custom valve build in stainless:mad:
There where concerns that the head seats would not take a satisfactory 3 angle job but JC was able to.
To further frustrate matters there are issues with spring heights due to the odd WBX setup.
Up shot is that despite a lift of 500' being plausible the lack of spring travel makes bind a higher risk.
JC has played around with several retainers, both aftermarket and stock, but not been able to get the travel required.
In the end stock T1 combined with his single springs provided the best compromise, but he advises to run 1.25 rockers rather than 1.4 as it's too close to call with 1.4's varying sometimes upwards. Bugger :(

Anyway, moving onto more pressing matters.
In order to check rod/camshaft clearances and backlash I needed a suitable stand.
Building an engine in your living room is great for cleanliness but not ideal for engine stands:lol:
With that in mind I knocked up this:





The wood used was just hanging around as it's warped, but it's sturdy enough.
I knew all those woodwork classes at school would pay dividends, my teacher would be proud:lol:
Once all the parts arrive from JC I can begin building the bottom end.
 
#26 · (Edited)
My new Torque Wrench arrived yesterday :D

NOS for a good price but being the 70 to 350nm one it's no use for most of the engine build other than the rod bolts and flywheel bolts.
I have an old skool style wrench for everything else.
It will, however, be very useful for heavy duty stuff like hub nuts and suspension bolts!

The conrod bolts are 12 point imperial requiring the purchase of a snap on socket.

Torquing to 50 lb/ft was a doddle on my new engine stand :crazy:

The bolts have been through 3 torque cycles as instructed but I may do another this time checking the stretch despite these being new.
For now the crank and rods are packaged up to keep things clean.
 
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