Headwork On A Gti-6 Engine?

[Joshy 0]

Right, I currently do not know what I should do regarding my GTI-6 engine, or more specially the head. When I bought the car it was a tapper, but I drove it around regardless (praying that it wouldn't drop a valve) but very recently the HG blew, which has given me a bit of a kick up the backside to get some vital work done to my car.

 

Now I am wondering what is the best route to go regarding my head. The choices seem to be:

Source a known good standard head and stick it on.

Remove my current head, have it skimmed (possible problem with GTI6 engines?) and have it rebuilt to standard specifications

Remove my current head, send it to an expert and have them port, polish, gas flow, etc and have it rebuilt with as fuirty cams as I can get away with on a standard bottom end

 

Ultimately my power goal would be a rather "tame" 200BHP, most likely via a set of ITBs and I have no real interest in going any further than this, so am I right in thinking that a ported cylinder head may be overkill for my target? Surely ITBs and well mapped management should push me into the 2XXs alone on a standard head?

 

It is also worth noting that I won't be fitting ITBs for at least a few months, so am I right in thinking that a cylinder head that has had work done to it may pose some drivablilty issues on a standard ECU?

 

Thoughts?

 

Thanks

[welshpug 1,661]

You wont need much done at all to these heads until your pushing well into the mid-high 200's, they are extremely good as standard, so yes the right combination of parts will get you over that 200 mark quite easily.

 

The main problem with this engine is the lack of clearance to the pistons at TDC, even more so if you skim the head.

 

 

Have a look here for what I found when checking out the most common cam upgrades and how safe they are in a standard bottom end; http://www.306gti6.com/forum/showthread.ph...4146&page=1

 

 

basically not a lot will go in safely!

 

If you do plan on going wilder its a good move to either get a set of aftermarket pistons, or get your original ones machined to suit Colin Satchel (eeyore) and Martin Price (CRF450) can both sort them out for you.

 

Bear in mind that the standard 10.8 is ok for most cam upgrades, but the wilder you go you will need more compression.

 

a worked over cylinder head alone wont cause driveability issues, but any cam upgrade will, you can get the standard ECU mapped to cope with the milder end of upgrades, but afaik the only person that can do that is Wayne Schofield at Chipwizards.

[DrSarty 90 1 Cars]

PeterT does both Mi/S16 and GTI6 fast road, reprofiled cams. He knows what he's doing; and don't be under the illusion that a regrind is any less of a cam. Extremely good pricing too, and you won't be suffering from issues pushing the valves nearer and nearer the piston crown.

 

That is unless of course you skim the crap out of the head.

 

And I simply wouldn't waste any money on extensive head porting and certainly not polishing. There are a few threads on here that show that style of head having the ports slightly reshaped, but that's really on the XU10J4R and XU7JP4 heads. I'd leave it standard if 200bhp is the goal, only removing any factory anomolies in the casting.

 

With a decent inlet cam, well timed, a good manifold (inlet and exhaust), 40mm plus ITBs on a decent ECU well mapped, you're 200bhp won't be far away. Dan Taylor's GTI6 shows a great standard of work and performance.

 

Even on a std inlet you should see 180 plus with a well built engine, properly managed on a clever cam.

 

Good luck with your project.

Edited February 28, 2010 by DrSarty

[Joshy 0]

Thanks for that guys!

 

Just what I wanted to hear to be honest. I have liked the sound of fitting a PeterT regrind since I bought the car, seeing as how everybody seems to rate highly but back in my head I couldn't help think "You get what you pay for", but I think I'll go with a regrind after all .

 

What would you suggest I do in terms of a standard cylinder head then? Is it really worth the expense of having the cylinder head completely rebuilt, or is it worth taking a risk with a second hand head from another car and simply changing the Inlet cam on that? The issue with my current head is that I do not know what skim it is running, or what work has or has not been done, but I do know that once upon a time the engine fitted in my car was fitted with some lairy camshafts... Although saying that, I won't know what sort of life a new head would have lived either!

 

Would rebuilding even be worth having a short myself? I have taken apart and put back together heads in the past, but I'm a bit more weary doing the job on my own car rather than a training engine on a rig .

 

And if I do keep my originally head, am I still best of getting the head a skim regardless? When the HG blew it did not excessively overheat (as soon as the fans kicked in it didn't creep above 90c-95c).

 

Thanks Again.

 

Josh

[camgti 56]

Hey Guys,

 

Take a look at this thread. I think it will give you an idea of what to expect when things are done after research and development and when things are done right.... Before ITBs check it out...

 

Cam

[Joshy 0]

Hey Guys,

 

Take a look at this thread. I think it will give you an idea of what to expect when things are done after research and development and when things are done right.... Before ITBs check it out...

 

Cam

 

It'd help if you posted a link!

[andyjstone 6]

I'm running a more or less standard QEP head on standard bottom end with Jenvey 45s and K3 management and it makes 190.

 

Andy

[CaptainK 11]

I'm running a standard bottom end GTi6 (albeit all of the engine is rebuilt), using a set of Colin Satchell ITBs, a set of Catcams and properly mapped by Sandy Brown using a DTA S40 Pro and mine is running at 190bhp. Like yourself, I was seeking the magic 200bhp, but mine was mapped more for driveability throughout the rev range and also to allow for me using a sports cat on it. Its perfectly quick enough as it is now.

Edited March 8, 2010 by CaptainK

[camgti 56]

Sorry Boys,

 

this is the link i should have included. Seem to always forget the main bit..!

 

http://www.aussiefrogs.com/forum/showthrea...ght=grahams+205