Top end rebuild. Opportunity for performance upgrades?

[nolegjoe]

Hey folks.

my '92 GTII 8v when in to the garage for a clutch replacement, and as is always the way the guys have found exhaust gasses coming into the coolant and overheating as well as a bunch of seals that have gone. Looks like it's top end rebuild time!

While they're in there and have access, are there any performance upgrades I should consider? I'm not looking to build a complete monster, but a little more pep would be appreciated. First thing I'm considering is a replacement exhaust manifold. I've read that the original C-clamp manifold is a performance disaster. Anyone know anything that's a good replacement without needing a completely new exhaust system?

Thanks a lot!

[mark1gls]

I would get the head skimmed, replace valve guide seals and check the valves and guides for wear (probably will need this) good decode and reseat the valves so they seal well (around £300) for head work and then leave any performance mod as port and polishing is expensive for little gain.

Fit a 4,2,1 stainless manifold and get it wrapped to keep the heat down, this will fit to your existing exhaust, you will also need to wrap the rubber boot on the steering UJ as the manifold is very close and they can catch fire!

Yes C clamp toilet bowl manifold is terrible for performance, when I fitted a 4,2,1 manifold I noticed performance gains especially higher up the rev range, from 4,000rpm to 5,000 it keeps pulling.

Other manifolds is the VW 6 bolt type fitted to tin top Mk1 Golf GTi and early Sciroccos can fit and will help with performance but finding a good one is not easy as they will be old and 2nd hand.

Not sure how much performance gains there is but a K&N panel filter in the original air box should let more air in and lasts for years so will pay for it self as no more new air filters every year. Don’t go for the K&N filter on top of the carb as engines work best with cold air going into the carb and the air around the top of the carb, just above a hot exhaust is not cold air…

If you still want more power later on then a 2l engine from a later Audi/VW fitted to your refurbished head is another idea?

[chopperoli]

I would recommend some basic cleaning up of the inlet port casting around the valve seats

[nolegjoe]

thanks for the advice! Would love to hear a bit more about this 4-2-1 manifold! Don't suppose you have any links to one I can look at?

Cheers

[mark1gls]

Well here’s the problem, I don’t have a Mk2 Scirocco. I fitted one to my Mk1 Golf cabriolet and I brought a raceland manifold years ago and I don’t think you can get them anymore, the Mk2 Scirocco should have the same exhaust, running gear etc as the Mk1 Golf cabriolet.

There is some pictures here of the manifold in my thread
https://vwgolfmk1.org.uk/forum/index.ph ... e-1988-gti

I’ve seen a few manifold like this fitted to Mk2 Sciroccos but they may need a little modding to fit but not sure.
https://www.ebay.co.uk/itm/324030031648 ... R-qO58TCYQ

[nolegjoe]

Hey, thanks for the link! I had previously seen this manifold before, and was slightly put off by its ebay-ness. Scared to ask my professional mechanic to fit an ebay part :D

maybe I'm just being an idiot and its actually solid though!

[whiteshark]

Ask your mechanic first if he's willing and has the time. My mechanic made me do it myself but he let me use one of his lanes with a lift and talked me through it while he was working on another car. The first time I did this the manifold was for a left hand drive, even though it was not advertised as such so was a bit of a balls as it did not fit. A four branch manifold increases your acceleration and is worth the money. Post a wanted on this site as I'm sure someone has one lying in their shed or garage.

[nolegjoe]

Thanks mate! Will post on Wanted.

You think the ebay one linked above is no good?

[whiteshark]

As it's from Germany, built for a left hand drive. Put a post up on this site to get one for a right hand drive to keep you right. The last thing you want is to start this job and whack on a manifold that touches your floor bulkhead.

[whiteshark]

Also consider changing your engine mount bushes to polyurethane. With a four branch you want less movement to prevent it cracking or splitting.