The V8 Owners Forum -

Bit of an odd one - I have just pulled the valley gasket up (tin) whilst removing the Offy manifold to have it milled at a lower angle and it had evidence of some porting work at did the inlet ports - also had some strange remnants of numbers in the floor of the ports 21 24 19 etc.

Its an old engine - a 9.25CR P6 engine but its very very clean and the internals look very good - a check on the cam in comparison to Vitesse cam and a vernier on a lobe gives a 40 thou higher lobe than the Vit. Cam has a purple splodge on the end. I guess the only way of telling what it is removing it and inspecting the end for marking and not any casting idents

The followers are also different from the two stock types that I have in that the centre looks to be in two parts rather than one - Does this indentify a hi-rev type?

The head gasket I expected to see a tin type - but this is thicker and has lugs sticking out into the valley area to cover additional bolts - as if for 6 bolt - I dont know how many holes the composite gaskets have as I only have some old tin ones. In my Hardcastle book there is a picture of a McCord Permatorque that looks like it could be similar any suggestions?

Cheers

Andrew

No one

Andrew

I missed this one.
If the lifters have a separate inner ring to the outer ring under the circlip, they sound like Rhodes hi rev lifters.

Cam could well be a higher lift model to compliment the lifters, and the head gasket is possibly a composite one. Without some pics its hard to tell.

Andrew,

The head gaskets are oldsmobile 215 which is the only 215CI engine in the GM family tp have 6 bolt heads and wedge shape combustion chambers, the valves were also on the centre line of the bore which is interesting. This information from David Hardcastles book.

Have you checked the heads to see what they are?

Kevin.

I had a Realsteel typhoon in my old 3.5 lump, that had a purple blob of paint on it at one end!

The standard follers that I use are also in two parts for the centre bit, there is the piston type bit then a cup bit on the end.

Pete

Forgot to say about the paint on the cam. My Typhoon also has a purple blob.

Thanks guy's

The heads are Rover - Birmal ERC 0216 ( only marked under rover cover) single valve springs fitted and they are less coils than stock ones. Old P6 heads I have are also Birmal but a different number so not sure if these ones are machined for double springs anyone know if the 9.25 engines are single or double springs as standard? Heads have the non seal type guides.

So looks like someone may have been shopping at real steel and done a cam swap.

I will try and get a snap of the lifters - but as a better description under the circlip there is an outer tube and then the inner piston inside - picture in Hardcastle tuning book on page 116 for the gasket - pictures I have seen of the standard composite does not have the valley area bolt holes.
The followers are similar to those on page 108 described as standard - but the standard follows I have are more like the Crane ones but without the lettering.

I have measured the rocker pedestals and they are stock so no machining done to correct for geometry of the higher lift cam - but then again I guess you would also need adjustable push rods to maintain the correct lifter pre-load. Do most people just put up with the error in the geometry and live with the extra valve side loads?

Reason for the questions is that I was going to just throw this "old" engine back in the car after the chassis rebuild whilst I built up a warm 3.9 - Now I find that I am am lucky enough to have warm 3.5 with many of the parts I would have bought for the 3.9 - so do I just buy a gasket set and build up the 3.9 now as its little real expense to what I was expecting.

Cheers

Andrew

Darkspeed wrote:Do most people just put up with the error in the geometry and live with the extra valve side loads?

I can't speak for anyone else but I got the heads machined 1.5mm where the pedestals bolt down. (The seats are NOT parallel to the gasket face of the heads).

I then used the RS adjustable pushrods. My 3.5 heads have had 70 thou skimmed off them to suite my 4.6 block and pistons. Due to all the machining I had to get the pushrods shortened by 4mm. You will have to work out whether you need need to do the same if you go for the pushrods. If you do end up shortening them then be aware that there is an internal step that needs drilling slightly deeper so that the ball ends will sit in the tube properly.

From what I've seen by looking at the wear pattern on even standard engines the geometry is not very good. The wear on the rocker pad indicates a nice line contact with the tip of the valve at zero lift but is almost a point contact at full lift. (The opposite situation would be much better).

You will propably have to file out the push rod holes at either end of each head, all the other holes seem OK. (Maybe the two holes at either end, IMHO filing is better then drilling as you can elongate the holes just in the required direction)

I went for 20 thou preload as this is good for BHP above 5k RPM.

I'd check the cam and followers very carefully before deciding that they are OK to use. I was going to use my typhoon in my new 4.6 as it had only done 5k miles in my 3.5. When I checked three of the lobes were knackered! I'm not saying that this will be the case for you, I did not own my engine when it was first run so the cam may not have been run in properly.

Pete

Cheers Pete some useful tips there that I will certainly keep in mind.

Andrew