Project performance WBX build - Page 2 - VW Forum - VZi, Europe's largest VW, community and sales
 
Machine 7, high quality air-cooled  restoration and performance parts

     
 

Go Back   VW Forum - VZi, Europe's largest VW, community and sales > CLUB FORUMS > Alternate Engine

Alternate Engine Got a Scooby motor in the back of your dub? Or a V8? Alfa? You know a Porsche motor drops straight in - right? This is the forum for you. Please, no 'For Sale' or 'Want To Buy' ads, plugs for your 'business', links to 'for sale' ads or Ebay links to your (or your mate's) auction (use the VZi 'Classifieds' section) - this also includes thinly veiled 'What's My Car Worth?' threads and "Who Can Sell Me A . . ." posts.

Machine 7, high quality air-cooled  restoration and performance parts
Reply Post New Thread
 
Thread Tools Rating: Thread Rating: 3 votes, 5.00 average. Display Modes
Old 15-05-2015, 07:56 PM   #11
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

Well my weighing scales finally turned up.
The results are going to be a problem

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

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

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.
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:23 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 07:57 PM   #12
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

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.
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:26 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 07:58 PM   #13
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

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
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.
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:29 PM..
iain ambrose is offline   Reply With Quote
 
Old 15-05-2015, 07:59 PM   #14
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

Today's job, porting

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)
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!
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:33 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 07:59 PM   #15
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

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
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:37 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 08:00 PM   #16
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

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 92 including delivery (They are 325 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
Ah well, keeps me out of trouble.
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:40 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 08:01 PM   #17
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

Result! The head was first listed for 140, I was tempted but let it run.
When it was relisted for 80 + 12 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

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
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:43 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 08:03 PM   #18
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

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.
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:45 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 08:03 PM   #19
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

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 10 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.
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:48 PM..
iain ambrose is offline   Reply With Quote
Old 15-05-2015, 08:04 PM   #20
iain ambrose
I'm not an addict... honest!
 
iain ambrose's Avatar

Trading feedback: (2)
 
Join Date: Jul 2005
Location: Stock
Posts: 4,218
Default

Alternator rebuild complete.



Looks much better



This does mean the heads will also need painting now
__________________
DJ Mixes http://www.youtube.com/user/djambrosia

Last edited by iain ambrose; 17-10-2017 at 10:50 PM..
iain ambrose is offline   Reply With Quote
Reply Post New Thread

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 09:44 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

Disclaimer: For recreational purposes only, some assembly required. Any resemblance to real persons,
living or dead is purely intentional and the site admins are not responsible for direct, indirect,
incidental or consequential ridicule resulting from any defect or failure to perform. No animals
were harmed in the creation of this forum. Colours may fade over time. No other warranty expressed or implied.

volkszone.com

SupportingSupporting Brad's Cancer Foundation

 










 
© Volkszone • Terms and Conditions of use



volkszone.com is an independent Volkswagen enthusiast website owned and operated by VerticalScope Inc. Content on volkszone.com is generated by its users. volkszone.com is not in any way affiliated with Volkswagen AG.