V8 overhaul advice

[Barkychoc]

I've been reading the info on the RPI website about V8 engines, and the 14 bolts in the cylinder head being an issue and that it is much better to fit just the 10 main head bolts.
Anyway I'm rebuilding my V8S and had decided to strip the engine to do this while its all in bits (and also to try and stem the oil slick leaking out of the sump).

Today I took the exhaust manifolds off - and was surprised to see that it already has only 10 head bolts fitted.
Is this standard from new on a TVR fiddled with V8?
I can't now decide whether to take the heads off or not - the engine runs really well though I still intend to have the cam out to check it. It has done 66000 miles, and RPI said with 60000 miles plus and 14 bolts the head gasket will begin to leak - but if I have 10 bolts already does that mean I needn't worry.

Here's the RPI link if you want to have a read ---> http://www.rpiv8.com/engine-4.htm#gaskets

Cost is a factor here - I don't have a bottomless pit of cash to throw at it.

All advice appreciated.

Chris

[dwgriffith]

If it's running OK leave it alone. Do something more useful with the money.

[griffter]

My '92 Griff had 14 bolts in the 14 bolt heads. The 10 bolt heads were only produced from 94 or 96 or something - way after the last of the V8S were made. Seems like your heads have been swapped at some time in the past.

[Barkychoc]

Sorry maybe I wasn't very clear - I have 14 bolts heads but only the 10 bolts are fitted.
From the bit sticking out the side it seems the head gaskets are composite aswell not tin.

Edited by Barkychoc on Saturday 29th March 16:23

[dwgriffith]

They've been off already then.

[350Matt]

You might want to CC the heads while they're off as the composite gaskets are a superior part but they are thicker so will drop the compression ratio and therefore power.

However if whoever did the work knew what they were doing (and the 10 bolts used implies that they did) then the heads will have been skimmed to compensate.

Matt

[Tahiti450]

350Matt said:

You might want to CC the heads while they're off as the composite gaskets are a superior part but they are thicker so will drop the compression ratio and therefore power.

However if whoever did the work knew what they were doing (and the 10 bolts used implies that they did) then the heads will have been skimmed to compensate.

Matt

Do you know if it is fitted with composite gaskets, wouldnt necessarily be so.

[GreenV8S]

350Matt said:

However if whoever did the work knew what they were doing (and the 10 bolts used implies that they did) then the heads will have been skimmed to compensate.

It wouldn't be that unusual to exchange the heads if they needed servicing, perhaps the originals have been upgraded to 28cc ones.

[Barkychoc]

I think they are composite gaskets as there's a little bit sticking out the side - it seems to be a grey covered metal gasket. Is this the construction of a composite gasket?

[Tahiti450]

Barkychoc said:

I think they are composite gaskets as there's a little bit sticking out the side - it seems to be a grey covered metal gasket. Is this the construction of a composite gasket?

Sounds likely that they are composite then, the shim gaskets are simply wafer thin steel sheet (beer-can gauge). The composite gaskets are about 1.5mm thick when compressed (hence the increase in combustion chamber volume and reduction in CR when these are fitted as opposed to the shim type). The composite gasket is of traditional construction with a sheet of presumably metal reinforced gasket material with sheet metal shielding over the sealing faces and flame ring areas.

Edited by Tahiti450 on Tuesday 1st April 00:05

[Barkychoc]

Well thanks guys for all the info.
I'm going to work on the basis its working well so don't with it.

I'll still check the cam and regasket the timing cover and sump etc to stem the Exxon Valdez effect.

Chris