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Recommendations on building a mild 1776 cc engine for my 1303.

5442 Views 37 Replies 10 Participants Last post by  qwan
I am building a stock looking 1776 cc engine for my 1303.

Any comments suggestions and specially experience with a similar setup, on the specks below, are most appreciated?

What i want is a civilized easy driven engine that pulls from low down.
Of course I want as much power as I can get, but not on the great expense of low down power and torque.
Going from 1300 to 1776 will naturally give a great deal of what I want, but maybe there are more easy apples to pick?

I will use:

Cast AA pistons and cylinders.

AB 1300 engine case – AS41- With Hover mods.

Full flow oil pump / filter.

Stock crank, con – rods.

Stock TP heads, and do a little flow work on them

34pict carburetor – MAYBE a progressive Weber.......

Probably stock valve train with bolted rocker axles.
Depends on whats needed for the cam I am going to use.

CR 8 – 8.5

Stock looking exhaust with CSP High Flow tailpipes and either I will mess the internals up in the stock exhaust, or maybe buy the CSP stock looking one.

As I don’t want a screamer and as I rarely will see over 4000 rpm, I am a little I doubt about if I just should stick with the stock cam or go for a mild upgrade.
Have tried to order a CB 2280 cheater cam but the order were canceled because it is not available any more.
That leaves me with stock cam,
or maybe an Engel W90,
or maybe 1:25 rockers with stock cam is just what I need,
or if some of you folks have a better suggestion?

Recommendations to the rest of the setup is of course also most welcome.

Have been looking a little towards this setup CSP has posted, using a W90 cam, in conjunction with their High Flow tailpipes.
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Have already got it linebored ,by someone else with the right tooling, who knows how.

My oldest son is a toolmaker, therefore the machine work is for free. 😁
Have the bores been inspected and found to be correct? 20 microns is a tolerance I have never in 40+ years seen achieved by common or garden lineboring techniques which most use, but I have seen the destruction it leads to. I have been told too many times by VW 'engineers' that they set the cutters with a tenth thou' clock, simply assuming the holes will end up equally accurate. Undersize or oversize, the wrong size is storing up troubles for what is essentially building a block of new flats on old bungalow foundations...
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I won't entertain an old case, too risky
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Everything Beetle related has been on halt for a while, but now I am back on the track again...

The guy who have line bored my engine case is a dedicated air cooled mechanic with several hundred rebuilt air cooled engines below his belt, and beside that he is a machine engineer with his own workshop.

He has developed his own system and tools where the engine block is fixed to a lathe.

A lot of people have, with great success, bought rebuilt engines from him and have also used him for just line boring.

I have no doubt that the work he has done for me is top class!

But said that, if money were no concern I would just have bought a new engine block.


Planing the last things in the configuration of the engine, and have been thinking a little about the oil cooling system.

I am going to use an external oil filter using the fancy ”EasyFlow with Pressure Valve” oil pump

from CSP.

Considering a larger external oil cooler instead of the original one.

If I do that, the question I have been thinking about is, if I remove the original oil cooler, remove the doghouse and block off the exit to it, will the extra air giver a better cooling of the engine, especially to the left side of the engine?
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Leave the cooler where it is. There's no huge positives to gain.
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im running an 1835cc with standard cooler no problems with overheating, make sure all cooling tin is in place and seals
Ran a 2007 in a Bay Camper for 50000 miles without extra cooling. Not a problem unless you plan to try and cruise everywhere at warp speed...
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Thanks all.

Have bought a new standard oil cooler and will monitor the oil temp. If it is getting to high for my liking, I can always later ad a oil cooler more in conjunction with the oil filter installation.
Thanks all.

Have bought a new standard oil cooler and will monitor the oil temp. If it is getting to high for my liking, I can always later ad a oil cooler more in conjunction with the oil filter installation.
It takes no more power for a 1776 to push a Beetle along at 70mph than it does a 1300. It might run marginally hotter than a stock engine due to reduced fin area but this can be addressed with cooling system tweaks. Only repeated hard acceleration/braking and cruising at illegal speed will overheat a properly built oversize engine.

Wil your engineer provide an inspection certificate? If not, or he is offended to be asked, you are quite naïve to have 'no doubts...'. I have seen line bored cases as much as three thou' out of tolerance - this particular gem having been done by one of the real 'Big Names' of their era. The engine ran for 30 seconds before seizing solid.
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Do you ever get bored telling everyone how shit line bored cases are? 😂
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Just hoping to save people from the expense and disappointment I have seen so many times over the decades...
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I do get that, but there must be thousands of them out there that work really well day in day out?
I used to send 10 cases at a time off to John Maher in the 80's. Quite often 5 of those would be scrap.
Scrap? Why?
Too far gone on the main bearing saddles and or sprung centre main saddle.
Scrap? Why?
Further, magnesium has a fatigue life, just as does aluminium (think exploding aluminium crank pulleys - ever wondered why VW didn't do that in their weight-savings quest?), and case cracks are common; how many folk out there crack-detect their cases before stuffing in and bolting on all those expensive performance goodies? I've said it before and I'll drone on like an old curmudgeon and say it again:
Don't build a block of flats on bungalow foundations.
The general lack of understanding of even basic metrology is all too evident in the VW engine building scene, and the days of bolt-together quality engine parts was gone three decades' ago. Yes, there are line bored engines happily chugging away, but for those of us who consider a 50 000 mile engine life to be a minimum, they are unworthy. A weekend toy with little mileage? Often no problem. A reliable engine doing 20 000 miles a year, year after year for business as I used to? Probably not, but don't be surprised to see the oil light come on at idle after a long motorway run with a few thousand miles on a line bored case!
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I always regretted not going 1914 instead of 1776. If your studs are going to be compromised then don't but for a small price increase in the heads you get a more powerful motor. I ran a mild 1776. Stock heads and valves diy polished and ported. Dual 34s. Engle 110 (but I had the crank balanced so would rev higher than stock)
Tbh i would save yourself a heap of time and money, as if your going to stick with a single carb I'd just slip in some 1641 barrels and be done with it. Difference between a mild 1776 and a 1641 is only really noticeable on a big hill.
Good luck 👍
Thanks all for your considerations and advises.

I appreciate it all, and have taken it all into consideration and weighted it up into a cost benefit analyze.

Regarding the engine case.
With a new case at 1.600 to 1.800 Eur, and a toughly examination of my old case.
I have no hesitation in using it.

Further more I have actually worked on old cars and engines for the last 35 – 40 years, and have always been able to produce a usable result.
Even though I have a long mechanical experience I don’t consider myself to know everything and have the only right solution to everything, therefor I in most cases try to get some second opinions and talk to people who have been handling the same kind of task I am about to perform.
And there are always someone else out there who has an even better solution, than you can come up with.

Line bore.
Just to clarify.
The person who line bored my case is not just some-random-backyard-mechanic, but he has a excellent reputation, and my reason for letting him do the job were not because he said he could do it, but because I know of, and have talked to different people, in person, who have used him, who, among others, have been driving around most of Europe on holidays in there Bus for several years, and their engines runs still just fine.

Besides that I don’t buy that, that all old cases are scrap. Many are, but some are also reusable.

Not saying a new case not could have been the best premium outset, but at around 1700 Eur. and all the examination there have been done on my old case.
I am ready to take the risk.
After all.
It is not rocket science , but only an engine, and if something goes wrong, I will just take it apart and rectify it.

Parts have already been bought:

Thick wall 1835 cc PC.

Engle W90 cam and Engle lifters.

New cam gear.

Harder valve springs.

New valves.

Bolted rocker shafts.

Swivel feet adjusters.

200 mm. flywheel and clutch to go with it.

CSP full flow oil pump with build in pressure regulation.

Used 34 pict 3 carburetor. The venturi is going to be bored up to 28 mm. and the manifold centerpiece is going to be fabricated with an internal diameter of 34 mm.

Plus a heap of other small items.

Still need to decide / get the exhaust, but leaning against the stock style CSP one.

Flywheel, pressure plate, crank and pulley are going out to be balanced individual and together.

Pistons will be matched and conrods end to end balanced.

Heads have already been machined to 101 mm. and also for bushings for 12 mm. long reach spark-plugs.
Still have to install new valve guides and cc them to 53 cc to get around 8.7:1 compression, with a deck height of 1 mm. or 0,04 in your parts.

Still waiting for a vacant milling machine to mill out the engine casting for the 1835 cylinders.
If it takes to long I will pay for the job elsewhere.
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Looking good Mr dk bug.. from what youve said above.. take your time, build it nicely with good tolerances and it will serve you extremely well (y):)....

Don't forget the -
air filter-(modded stock style works well!, cheap chrome ones will kill the power),
ignition- (waterboxer/tzh/late bay style, mallory, csp pacemaker, decent original used svda, 123 ignition)are all good and can have vacuum, which you need... cheap chinese ones WILL have far too much vac advance, and the electronic stuff in them doesnt last.
exhaust - csp hi flow with the high flow tail pipes as well.. vintage speed stock/125hp style or "possibly" a decent 4into1 with single muffler... that's a last resort really, however.. also, don't fit a completely stock exhaust. Again, Kills the power.

Good luck with it!
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