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Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Sun Jun 05, 2016 5:37 pm
by capitolatim
I acquired a nice 914 with a 2.4 /4 engine. Ran very strong but was leaking oil around the cylinders and cam seals, etc.
Local Porsche shop disassembled the engine and recommended against trying to seal the cylinders to the case as it had very little surface remaining.
So here's the question.
Assuming the crankshaft and camshaft are still good and I do want to keep the Dellorto 45's and 1 5/8 European racing headers( no heat exchangers) and use the front oil cooler(Patrick GT Conversion).
I’m thinking I must find a 2.0 Short block, or will a 1.8/1.7 case work?
Obviously I will have to find barrels and pistons for whatever case I use.
Rod journals on a 2.0 are smaller, so if I keep the crank I must use a 2.0 case, eh?
I found a set of 2.0 heads today at the PCA swap meet, hopefully they will check out.
Final question, what are those 2.4 cylinders & Pistons and heads worth?
Thanks for reading.
Cheers
Tim

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Sun Jun 05, 2016 9:14 pm
by Piledriver
Welcome to the STF!

Don't bet a dime a Porsche shop actually knows what they are looking at.
Unless they build HiPo T4 motors all the time, they only know stock engines.

Thats a pretty typical leak (seeping jugs anyway) and not remotely cause for a new motor.
They want to build you a new motor.
Great for them, but bad for your wallet, and also likely totally unnecessary.

Even bone stock aircooled T1 or T4 engines ALL start to leak like that after awhile, at least seep at the jugs.
(both ends) air cooled 911s suffer from the exact same thing, just to a far lesser extent. (usually at head)

The sealing surface on the big bores is thin.
It's not an actual issue.

Unless the case was cut too large, at worst you may just need to have the case decked.
Also heads checked.
It may just need cleaned up and resealed.

Disassemble
clean, pull the studs.
have case checked out and decked if required, also have heads checked for flat, at least.
If you have any mechanical aptitude whatsovever, you can check the decks for flat yourself with a straightedge.

IF it needs machined, send it to EMW or RIMCO, there are a few other places that can do it right but a typical automotive machine shop will cost you 5X what someone that already has the tooling will charge, and is also more likely to screw up and scrap the case.
Send it to someone that does it all the time.

reassemble with same parts, don't mix up the lifters, have to go in same holes or its best to throw the cam and lifters out, expensive mistake on the Porsche shop..
Install base gaskets to set desired deck.

Use Permatex Anerobic sealant on the case, and a thin smear on the cylinder bases/gaskets.
It sets very quickly one the parts are together, but remains a gel ~indefinitely up to that point.
If you put it together with that sealant, mean it or it has to be cleaned off and reapplied.

The stock cases are all interchangeable with only fine detail differences, early cases are preferred to some extent due to thicker casting in places and perhaps better metal, generally avoid cases from Busses, they have had a long, rough life.

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Tue Jun 07, 2016 7:09 pm
by capitolatim
Piledriver:
Thanks so much for the guidance. I took the engine to my local machinist. He builds many motorcycles and air cooled VW race engines back in the day. He agreed with you totally and has a new project.

I did mix up the lifters(in my hurry to get out of Porsche shop) but he saw a bad flaw in one of the lobs, so now I must find a good cam. The engine has straight cut cam gears which I intend to keep.

Engine ran very strong, has Dellorto 45's and 1 5/8 headers( no heat exchangers). Got any recommendations on camshafts. I liked the torque and low end with the cam installed, 276 duration. 383 lift.

It's a street car.

A thousand thanks for the great advice.

Cheers
Tim

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Wed Jun 08, 2016 1:39 am
by Piledriver
Cool. :D

Pictures in the 914 forum when she goes together!

Favorite:
Webcam 163/86b on its std 104 LC (108 is std for anything else they sell)

You might like a Web 494 as well, less duration and lift but a bit rampy and hard on the lifters bores etc, dual springs recommended for the 494 and required for the 163/86B (or ~anything that lifts beyond ~440" at the valve).

Web cams are nitrided, No one else AFAIK (Other than Jake Raby) nitrides cams for ACVWs.

Google a bit and you'll understand why you want that.

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Sun Jun 19, 2016 4:51 am
by Type 4 Unleashed
The straight cut cam gears, since your going to keep them, put them on the shelf.

For a street car, forget about the strait cuts,, their cool at first, but you will get tired of them in no time, ask me how I know. They will whine you to death.

Run dbl thrust bearings on the cam and run the stock type gears.

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Sun Jun 19, 2016 4:37 pm
by Piledriver
Type 4 Unleashed wrote:The straight cut cam gears, since your going to keep them, put them on the shelf.

For a street car, forget about the strait cuts,, their cool at first, but you will get tired of them in no time, ask me how I know. They will whine you to death.

Run dbl thrust bearings on the cam and run the stock type gears.

Like he said.

T4 cam gears use a much shallower angle than T1s so have ~no issues.
T1s benefit from straight cuts much more.

Do make sure to use the dual thrust cam bearing set.

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Fri Jun 24, 2016 8:36 am
by aircooledtechguy
Piledriver wrote:
T4 cam gears use a much shallower angle than T1s so have ~no issues.
T1s benefit from straight cuts much more.
Not trying to stir the pot here, but have you actually looked at type4 & type1 cam gears and measured the gear angles?? They are exactly the same as far as I can tell/measure. Different diameters for the gears, but the gear angles appear to be identical.

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Fri Jun 24, 2016 1:20 pm
by Piledriver
I know that T4s have about the same cam bearing design, but don't eat the thrust anywhere near as bad as t1s with a stiff cam/springs. Dual thrust still suggested as that frequently is the first thing to go, T4s tend to last so much longer its a shame to have to pull them apart just for that, it was the only thing really wrong with my 400+K mile 1700.

I'll go dig up a T1 cam later, think I still have one from a WBX..

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Fri Jun 24, 2016 6:38 pm
by sideshow
WBX is the same as late T1

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Sun Jun 26, 2016 10:20 am
by Piledriver
Yep, angle looks identical.

I mistakenly accepted an explanation I saw that looked plausible in another thread by a usually reliable source.

I don't think the diameter difference is enough to explain the T4s not eating themselves while T1s do, so I am open to suggestions.

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Sun Jun 26, 2016 10:49 am
by Type 4 Unleashed
Could the offset lifter bores of the Type lV be a factor, where the Type 1 bores are evenly spaced ?

Re: Salvaging a toasted 2.4/4 back to 2.0 or so?

Posted: Mon Feb 05, 2018 2:01 pm
by Clatter
Did this one ever play out?