Longevity of tuned VW motor

[corduroyboy]

Hi, I guess almost all replica owners run a tuned VW motor.
Has anyone got any experience or ideas on the longevity of these things?
I've only ever run stock motors.

[Nige]

Its down to how well a hot motor has been built, but generally a Hot Type 4 will give more reliablility/longevity than a Hot Type 1. But then a hot Type 1 will cost alot less to rebuild.

[davidppp]

Revs and heat kill bug motors.

Any time you exceed 4,500 you knock thousands of miles off.

Any tuned motor will be making more heat..how much depends on CR, mixture, etc etc..

As a guide, we reckoned to rebuild a road rally bug engine (very moderately tuned 1600 TP with good cooling and 8.5:1 CR, fully balanced etc, flowed heads and standard cam, but nice twin carbs and 4;1 zorst every 20,000 miles at most. about 78 BHP flywheel on the rolling road....but it got revved to hold a gear between corners...and the case was usually worn enough to replace or recut the mains..

T4 is a whole nuther story....bit heavier stock, but its possible to lose weight quite well from them..

Kind regards
David

[corduroyboy]

Have got a 2000cc Type 4, twin 40s and Porsche fan - I know that keeping cool is part of the story. I guess what I am getting at is how much thrashing can they take?

Having said that, the crash test post is sure to lighten my right foot

[roger]

A friend has a tuned type 4 in an RSK replica and that got a fair hammering. It had covered about 25,000 miles with no apparent signs of wear, until..... an oil pipe came undone........

My own 150 BHP type 1 lasted about 20,000 on the original engine before I had problems but I think that was more to do with a poor rebuild. After the rebuild I did about 15,000 miles before I sold it. It was fine at that time. I do have a heavy right foot!

I have always taken cooling very seriously and had a fromt mounted cooler on my Spyder (ran at 85 to 90 degrees C). On my tuned 914 I have an oil cooler with fan and typically run slightly hotter (90 to 95 degrees C)

My view is that when doing a limited mileage the cost of rebuilding is not that great if you amortise it over 7/8/9 or even 10 years, in return for a whole lot of fun. (assumed a maximum of 3000 miles per year)

[corduroyboy]

Ta Roger!
What happened when the oil pipe came undone?

[roger]

What happened when the oil pipe came undone

After saying "some poor sod behind us has a problem - look at all that smoke".....knock, knock, KNOCK, KNOCK, KNOCK

[corduroyboy]

Ouch!

[davidppp]

Bit more..

The T4 motor will last much better, but still doesn't like the revs..

here the pistons seem to suffer most..the topring grooves wear badly for some reason when revved..

It is possible to use a T1 piston with narrower top ring..may be better..certainly much lighter..

The 66mm crank, used in 1.7 and 1.8 motors is much better all round BTW, unless for some reason you really want the huge engine..

They are more often than not usable without a grind(!), unlike the 2L 71mm which has smaller crank pins and flexes much more of course..

BTW, we were running two cars with identical motors as above, and rebuilds were a matter of policy rather than waiting for the need to become apparent..as has been said, the bits are/were cheap and the rebuild was much less than a day's labour if the case was OK,, by keeping fresh heads etc on the shelf..later we kept a case there too!

And I can assure you these motors were well and truly thrashed, day in night out..one car did over 30k in the year..
Dunno if all that nostagia helps !

Kind regards
David

[hot66]

Hi, I guess almost all replica owners run a tuned VW motor.
Has anyone got any experience or ideas on the longevity of these things?
I've only ever run stock motors.

don't worry too much about it, if the worst should happen then they a resimple enough / cheap enough to repair / rebuild.... anyway, I'm sure once you have some miles under your belt you'll be thinking of ways to extract more power

[Gone in 60 seconds]

Giles,
The Type 4 in question is going to be very lazy, it is 2000cc running majority 914 innards and full "911" cooling, I have also left you a Kenlow fan as my experience on the Gumball as stated in the thread above cooling is all I d worry about. Consider the car is ultra light and is being driven by a super torguey engine derived to pull a van/bus along at speed, it wont be effected by load. This is totally dissimilar to say a type 1 motor stretched to 1941cc and under labour at all times. I suggest the car will be frighteningly quick without a deal of effort.

All parts are cheap, but keep the oil temp down and you should have a very happy long term reliable engine

[hot66]

Hi, I guess almost all replica owners run a tuned VW motor.
Has anyone got any experience or ideas on the longevity of these things?
I've only ever run stock motors.

Now I know you are a 'northerner' , we have a superb engine builder in this neck of the woods. A significant amount of engines in the VW scene will have passed through his doors. He is also a very reputable 'cage' builder if you are thinking of having a roll cage built. If you need any help at all I can pass you his details.

[corduroyboy]

Cheers folks! Like that bit about frighteningly quick, James
Hot66 - My be considering 'cage - check out the crash test thread! In fact make that 4!
Who's the rebuilder then?

[stevesprite]

I would also be interested in a roll cage, any chance of some details

regards

Steve

[hot66]

The guy who I'm talking about is Darren, who owns / runs 'aircooled performance', based near Croft race circuit. Most of his cages are for VW drag cars, but all are custom made and extremely good quality. His number is 07712 016997 .

Give him a call to see what he suggests.