Aircooled VW South Africa

Thanks Nick, yes it went well till it started overheating, then it was back home being towed by the Beetle in 3rd gear.

Had a lot of fun with the nylon strap burning off at the exhaust every few kilos, but made it back home before the strap was too short.....

(Had to fix to the gearbox mount)

Herman

So that in itself was an experience not to be forgotton !
Glad you are safe albeit a bit cheezed off i'd say

Nick

Sorry to hear of your troubles Herman. I was looking forward to seeing your cars at the show, but will have to wait until next year... Sure you'll have it sorted in no time!

Thanks guys.

yes I was going against everything I preached so it had to happen.

Always said that a classic had to be driven short routs around the house, and then bigger and longer runs, till it had proved it will do a road trip.

But as they say, school fee's are a bitch.

Herman

No no no Herman. Maybe its your mechanical skills.

I absolutely love the challenge of taking a long trip with an untested car. Best way to check if you did a good job or not.

sean wrote: ↑Fri Feb 16, 2018 12:09 pm No no no Herman. Maybe its your mechanical skills.

I absolutely love the challenge of taking a long trip with an untested car. Best way to check if you did a good job or not.

Love a challenge like that as well, did it with the Bay to KKK last year, but then I was testing MY OWN work......

This time it was out of my hands...

Hey !!!! .. Wait a minute....Are you trying to insult my Angle grinding skills......??.





Herman

Motor is back in and running very sweet.

Will be following my OWN advise, and driving bigger and bigger circles around the workshop, till I have clocked up some mileage.

Will run it till the 1st and 2nd oil changes, so I have clearance on the parts for the run up the Sani.

Fitter Coil-Over shocks at the back, so I can get the ass up for clearance to get up Sani without leaving behind some valuable parts.

They will also help to get the wheels down for traction.

Will report back after run's

Herman

What caused the overheating... mixture/timing issues?

No, Internal heat generation.

Did some Googling, and found out that the 1915CC motor needs extra clearance, over and above the norm.

Also I think the vacuum advance brought the timing too early when going up hill, that it fired before clearing TDC

Have now blocked off the Vacuum and only using the centrifugal advance, and she runs much better.

Timing is now more in sync with the electronic ignition.

Thanks for asking

Herman

Interesting. The 94mm type 1 cylinders traded cooling fin space for larger piston diameter because of fixed spacing between cylinders. So more clearance between pistons and cylinders would allow more space when piston expands from heat.

What Porsche did in the 60's... was to specify more piston clearance for their higher output engines.
So the more powerfull "S" version had more piston clearance than the less powerfull "T" version of same cc engine.
In the mid 70's they went to alloy based nicasil cylinders which have their thermal expansion rate closer to that of aluminium pistons. So the cylinders also grow with temperature when hot, allowing less clearance to be used.

Also wondering... which distributor did you use? Was'nt there an issue with a distributor you initially had on the beetle?
The standard distributor's vacuum advance should fall away when putting foot to tackle a hill.

retrovan wrote: ↑Sat Mar 10, 2018 12:08 pm No, Internal heat generation.

Did some Googling, and found out that the 1915CC motor needs extra clearance, over and above the norm.

Also I think the vacuum advance brought the timing too early when going up hill, that it fired before clearing TDC

Have now blocked off the Vacuum and only using the centrifugal advance, and she runs much better.

Huh?
Herman, if the vacuum made the timing advance too much during wide open throttle, then you either have carbs which are far too small or you set your timing wrong.
Vacuum advance works at part throttle and advances the timing during low power cruising which lowers fuel consumption and believe it or not, actually makes the engine run cooler.
Centrifugal advance only will make your engine fuel hungry and will fry your exhaust valves at part throttle.

If your carbs are too small, you will still be pulling a vacuum under wide open throttle which will then advance your timing slightly and cause what you described.


I hardly know your engine builder but after having spoken to him a few times over the years and spoken to others that have had issues with his engines, I can guess at another two reasons why your car overheated.


My test drives are simple. Drive it up and down my property in 1st (100m). If it works, drive it 2km down the road at a normal pace. Turn around, nail it home. If it survives that, its ready for breaking in the rings...

Tony I agree with you, if you speak of an engine that has the right clearance,

But as Dawie said, you need that extra clearance, so should you not have the correct clearance the lower fuel usage ups the internal heat and there you go.

I am sure that when the motor has run in properly I could put the vacuum back and have her running like the beetle.

Have had 5 engines from him, and this is the 1st that gave issues, all the others I run in as I always do with my new engines, and never had issues with them.

Not sure if he knew about the extra clearance needed on a 1915 cc engine, most engine builders don't. I only learned about it when I investigated the reason why this engine, and not the others.

Hey ! happens, its fixed now, so lets learn from it.

Herman

I agree, the 94s do run very hot initally. But if you get kit made by Mahle you wont have any issues. Unfortunately, the "guys" in SA now are not importing Mahles anymore as they are too expensive and instead selling the new cheaper AA kits. These are known for their issues but the price is right. 4k locally instead of around 10k for the Mahles.

Herman, if you just went with a stock standard setup all your suffering would have been avoided.

Modified doesn’t last

But hey, of course you will insist to modify something