Help with RV8 Head bolts and Torque protocol

[The Moosehunter]

Hi Chaps. Help Please

Having fully re-built my 5 ltr Griff motor a few weeks ago, it would appear that the head bolt have slackened themselves off causing a head gasket failure. Definately set at 70 Lb Ft in the correct order and progressively and yet some are now as low as 40 Lb Ft.

I did re-use the existing bolts (rightly or wrongly) as they all looked AOK and the motor is not that old. Obviously now I have decided that may not have been the right thing to do.

I also put a small amount of Mobil 1 on the end of the bolts when I fitted them to help guide them into the block, again rightly or wrongly.

Questions

1 - If the heads require re-torquing, what should be the timescale / mileage after initial start up.

2 - What would you expect to be the average drop in torque values as a guide (surely not as low as 40 Lbs)

3 - Should the new bolts be lubed at all during install or should they be dry (if so ideas on cleaning my oily block threads ) or should they be loctited

4 - Existing bolts have the Land Rover part no of ERR 2943 and ERR 2944. Was informed that these are standard head bolts and not "stretch bolts" Please tell me this is correct.

5 - Am I a complete plum who shouldn't be let loose on the internal working of a TVR motor. (or behind the wheel for that matter)

Thought I had sufficient knowledge experience to tackle this job, looks like I was sadly mistaken

Help on this greatly appreciated

Assembly (with new bolts) taking place on saturday.

Cheers

Moose

Edited by The Moosehunter on Tuesday 19th June 11:12

[That Daddy]

I would strongly recommend getting your torque wrench checked/calibrated 1st

Edited by That Daddy on Tuesday 19th June 11:06

[ray_von]

The Moosehunter said:

I did re-use the existing bolts (rightly or wrongly) as they all looked AOK and the motor is not that old. Obviously now I have decided that may not have been the right thing to do.


5 - Am I a complete plum
Cheers

Moose

Edited by The Moosehunter on Tuesday 19th June 11:12

I thought that using old bolts is a complete no-no.
As for being a plum, I think your being harsh on yourself. I admire anyone who has the balls to take on work like this
So chin up and just remember, I AM THE LUCKIEST MAN ON HERE

[Talkwrench]

Thats frustrating bad news but the solution may be a simple one.
I'm pretty sure your information on the head bolts was unfortunately wrong. The bolts listed are stretch bolts and must never be reused.
New ERR 2943 and 2944 stretch bolts are tightened to 20ft/lb and then turned through 180 degrees.

The earlier non stretch bolts are tightened to 30ft/lb then 70ft/lb. I hope this helps!
All head bolts stretch & weaken a little over time so, for the minor cost of a new set, always replace them.
Oh, and by reputation, non stretch bolts are generally preferred.
Lightly oiling the threads is OK but instinctively, I wouldnt use something as tenacious as Mobil 1. Dry threads are the ideal if theyre new and spotless but a touch of WD40 or something similar will ease entry (ooh err... missus!) and not interfere with the correct torque setting. Never use Loctite on these head bolts!

[dnb]

When I spoke to Rob to buy my cam, he advised me that I should definitely put new head bolts in. I was planning to anyway given mine's a high mileage engine.

Mistakes are all part of learning, (that's what I tell myself anyway ) so whatever you do, don't give up!

[Boosted LS1]

Older bolts are reusable, new type bolts are TTY or torque to yield and not reusable. You've probably stretched them past yeild point.

Why not fit some studs instead from Real Steel?

Boosted.

[The Moosehunter]

Talkwrench said:

The bolts listed are stretch bolts and must never be reused

How stoopid do I feel now

I suppose that's what you get for listening to the wrong people

If I had known that they were stretch bolts I would have course replaced the lot

I guess we now move on to Head Bolts vs Studs argument

Any thoughts ?

Cheers for the info so far chaps. Nice to have an answer for the failure. Shame that answer is, me

[JR]

Can't remember the details but are you using the extra row of bolts that shouldn't be there? Hopfully someone like boosted or GreenV8 will clarify this shortly.

[TVRleigh]

ummm maybe I should replace mine,
As I changed my heads on my 89 4ltr V8 but used the old bolts,

I've not finished the engine re-build yet so would not be too much of a problem to change them.

So need advice on best bolts or studs to use, and best place to buy.

I think as its a older 4ltr I don't think I have strech bolts, but as said may be best to change them. suprized the ppl I got the new head from did not sell me new ones. (or did they was a while ago.) I know they sold me gaskets.

On a side note the rover hanyes manual say to re-torqe the bolts after 1000 miles. is this right or wrong, or only with non strech bolts.

[350Matt]

On the earlier engines ( pre-serp and some intermediates) they have a 3rd row of head bolts on the exhaust side, these bolts were deleted on the later engines as its was shown they actually distort the head rather than clamp it.

If your engine has them only torque the bolts up to 20ft/lb or so

I'd also thoroughly recommend using the composite gaskets and get the heads skimmed to compensate for the extra thickness

Matt

[JR]

350Matt said:

A proper explanation of my earlier comment

Thanks.

[Boosted LS1]

JR said:

Can't remember the details but are you using the extra row of bolts that shouldn't be there? Hopfully someone like boosted or GreenV8 will clarify this shortly.

Hi JR,

People don't usually bother with the outer row of bolts these days especially if using studs.

As for a stud debate, have a look here.

http://www.pistonheads.co.uk/gassing/topic.asp?h=0... and on the link to the V8 forums.

Boosted

[ed_crouch]

Problem with fitting head studs is that you may not be able to get the heads back on with the engine in the car, as the heads have to slide a long way up the studs to come off.

I think its a problem for Wedges, but not sure about Griffs...

Ed.

[Number 7]

I've been running ARP studs in the 4.3 pre-serp in my Wedge for several years. It has the drillings for the outer row of bolts, but I don't put anything in there at all.

7.

[TVRleigh]

I have new head's that don't have the extra row, as I know about that problem with the heads. I thought the compersit gaskits where thinner then the orignal ones. (that had a big copper ring in the middle. The 400SE was very high comp. and would pink a lot, so maybe a sight lower compression may help with this.

Main aim is just to get it running.

also anyone know best place to buy new bolts or studs.

Edited by TVRleigh on Thursday 21st June 17:43

[350Matt]

compressed height of the composite gasket is about 1.0mm (according to Real steel's website), std tin ones about 0.5


Matt

[TVRleigh]

I'm sure the one's I had was compersit with coper inserts. was told they was a TVR special. don't have them any more tho

[350Matt]

TVRleigh said:

I have new head's that don't have the extra row, as I know about that problem with the heads. I thought the compersit gaskits where thinner then the orignal ones. (that had a big copper ring in the middle. The 400SE was very high comp. and would pink a lot, so maybe a sight lower compression may help with this.

Main aim is just to get it running.

also anyone know best place to buy new bolts or studs.

Edited by TVRleigh on Thursday 21st June 17:43

Real steel sell lots of RV8 goodies


Matt

[Boosted LS1]

TVRleigh said:

I'm sure the one's I had was compersit with coper inserts. was told they was a TVR special. don't have them any more tho

Those are thicker then 'regular' gaskets. If fitting tin gaskets watch out for piston to head contact. You'll hear it as the revs rise

Boosted.

[TVRleigh]

Boosted LS1 said:

TVRleigh said:

I'm sure the one's I had was compersit with coper inserts. was told they was a TVR special. don't have them any more tho

Those are thicker then 'regular' gaskets. If fitting tin gaskets watch out for piston to head contact. You'll hear it as the revs rise

Boosted.

So would the compersit gasket be the same thinkness as the special gaskets, also I got the compersit gaskets of the same ppl I got the new heads from, so hopfully it should not be a problem.