Ah, damn.
Author
Discussion

markrichards

Original Poster:

150 posts

195 months

Saturday 28th April 2012
quotequote all
3 laps of VMAX = 175mph = head gasket failure....

Many thanks as always to Dave at Jetstream for picking me up from the bottom of the runway. Convenient breaking down 100yrds from them.

Cylinders full of coolant. Yet to take a close look to determine damage.

Any thoughts on what to do while the engine's in pieces are welcome.

daddysumo

2,545 posts

242 months

Saturday 28th April 2012
quotequote all
Depends on how much you want to spend...

951

614 posts

184 months

Saturday 28th April 2012
quotequote all
Yep, my 612bhp started out as just investigating a positive HC in the coolant test..... biggrin

Sorry to hear your troubles though.

Regards

Graham

markrichards

Original Poster:

150 posts

195 months

Saturday 28th April 2012
quotequote all
Not looking to spend huge amounts given the cost of the car year to date.

I reckon:
- Oil cooler
- Helix clutch

In addition to fixing the heads etc.

Gadgeroonie

5,362 posts

265 months

Saturday 28th April 2012
quotequote all
do the valve springs and fit a hot intake cam whilst the head is off

what spec is engine ? does it have forged pistons ?

R0162

2,435 posts

193 months

Saturday 28th April 2012
quotequote all
markrichards said:
Not looking to spend huge amounts given the cost of the car year to date.

I reckon:
- Oil cooler
- Helix clutch

In addition to fixing the heads etc.
yep thats where it starts, then it will be ..hmm while doing the heads i may aswell do this..and if i'm going to do that i may aswell sort that at the same time...oh feck it sort it all ..smile...after all if your doing clutch you may aswell upgrade gearbox ..lol

markrichards

Original Poster:

150 posts

195 months

Saturday 28th April 2012
quotequote all
Ha, you're likely right Chris.

It has the upgraded injectors, valve springs, forged pistons etc.

What do the hot cams do?

Currently running c.515bhp so not looking for power, just reliability.

951

614 posts

184 months

Sunday 29th April 2012
quotequote all
Unless you cut the chassis, the engine needs to come out to upgrade the clutch.

Do you already have the gearbox upgrades?

If you are not taking the engine out, the full race heads are about £600 + vat (well they were not too long ago), and the cams are about the same.

Even if you don't up the power, they will both take some heat & stress out of the engine as the turbos will not have to work quite so hard - but you would also need a remap.

markrichards

Original Poster:

150 posts

195 months

Sunday 29th April 2012
quotequote all
Thanks for the advice all.

What are the characteristics of race heads and cams? How do they increase power and do they change the tractability of the engine?

Cheers

951

614 posts

184 months

Sunday 29th April 2012
quotequote all
I can only pass on the advice I was given when specifying mine.

You can get heads that have been ported to let the engine breathe better and more efficiently. The full race heads go further and have more extensive porting right through to the manifold. Needed for 600bhp but also a good mod for 500 and may allow the turbos an easier time, thus keeping a bit of heat out of the engine.

Cams are again really only needed for 600bhp but are a nice mod for 500. Engine can rev higher and again will breathe better and more efficiently.

I have both and the car is still tractable at lower revs, but the cams can make it a little lumpy. Not a problem though.

The prices are for exchange units by the way.

Regards

Graham

Adrian W

15,449 posts

257 months

Monday 30th April 2012
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Iv'e not heard of race heads for a Noble, so am curious, normally this would mean PB valve guides(maybe re angled) recut 3 angle seats, one piece stainless or inconel valves, light weight retainers and a lot of porting. I thought all that people do for the Ford heads is a light clean up and flow?

951

614 posts

184 months

Monday 30th April 2012
quotequote all
Hi Adrian,

It's just what Dave called them, but I think he was only referring to the additional level of porting.

Maybe the description is a bit misleading, but they have much more than just a light clean up.

I think that the basic improvements are usually confined to a light clean up of the combustion chambers, but on these (which he also referred to as the 600 spec) there is a lot more work done and the porting goes all the way through to both the manifold faces, with the inlet ports also being opened up a bit too to match the lower manifolds.

Can't remember if it's a 3 or 5 angle valve cut - they're not just relapped though.

However, I didn't get the impression the valves, guides or retainers were any different. The springs are, obviously, but that's on top of the exchange head price.

Regards

Graham

Edited by 951 on Monday 30th April 13:05

Gadgeroonie

5,362 posts

265 months

Monday 30th April 2012
quotequote all
(3 angle valve seats are not really needed on a forced induction car imho)