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Valve Guides

Posted: Sat Sep 01, 2012 10:17 am
by johnwp5bcoupe
I have a pair of Efi ERC 0216 heads to go on my 1969 P5 coupe which I have owned for 39 years. The reason for changing the heads is I am fed up with trying to run smoothly on 95oct the engine has only done 38700 and will last me out :wink:

I would like to fit the later type stem seals but the guides I have need to turn down the step to fit them, this I can do as I have the machinery but need to know the measurements? I bought a step one off Ebay but the bore was 8mm and the new valves are 8.66mm so I dont know if that step profile is correct? are the new seals for the larger stem diameter?

I also want to fit new rockers and shafts as I am fitting all new valves, Rimmer Bros only want nearly £50 each for OEM Rockers :shock: so I have to go after market! are there a good type/supplier to go for steel are the cheapest but are they as good?

My last question if I go for composite gasket will I need to shim the Pillars and what will be the CR if I go for composite and what it will be if I use Tin?

Thanks for any info I am fine on the standard stuff :wink:

Thanks, John.

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Posted: Sat Sep 01, 2012 10:45 am
by DaveEFI
Just an aside, but if you don't do many miles why not use 97/8 octane super?
My high compression P6 ran happily on that. But you do need to make sure the timing is spot on and doesn't drift with wear, which usually means fitting electronic triggering. Also in theory, the MPG should be better than with 95 making it no more expensive in practice.

FWIW, I use Super unleaded on my SD1 EFI - and that covers quite a few miles each year.

Posted: Sat Sep 01, 2012 11:28 am
by johnwp5bcoupe
Hi Dave I use the Tesco 99 but if I hit the throttle hard it still pinks I have an SD1 front cover with the RR Electronic distributor tried the timing everywhere but still pinks, plus we have the extra 5% of Ethanol before long and at 10.5-1 I need to lower it a bit.
Thanks, John.

Posted: Sat Sep 01, 2012 3:55 pm
by SimpleSimon
As far as rocker arms go be careful as there are some real moody quality pattern parts out there that rattle around on the rocker shafts like a cock in a sock, far better to get yourself a set of OE used rocker assemblies off Ebay or similar IMO 8-) as new old stock is getting hard to obtain nowadays :cry:

Posted: Sat Sep 01, 2012 4:12 pm
by johnwp5bcoupe
Hi Simon thanks for the reply they are for sure Efi Heads as there is a very small indent in each inlet port plus they are waisted inlet valves the ones I have new aren't waisted but they will do for my old girl :wink:
Ok on the rockers I have the set that came with the heads but the shafts are scored and without buying new shafts I don't know how good the rockers are I don't like the idea of sloppy imported replacements OEM new are about £480 for each side!!.
Thanks, John.

Posted: Sun Sep 02, 2012 2:22 pm
by johnwp5bcoupe
A further question guys are the pre 95 guides longer as they haven't got the shoulder to take the latest oil seals? another way! the post 95 are including the oil seal the same length as the pre 95? and do they have a seal on both valves?

Posted: Sun Sep 02, 2012 6:26 pm
by Darkspeed
Compression ratio is piston dependent not cylinder head so you will not lower the compression ratio unless you are looking at also using composite gaskets

If you have the tools why not buy and fit a set of Real steel bullet guides - If looking to machine the seals in situ - the real steel guide shoulder for the seals is 12.51mm x 5.97 guide diameter 15.13 bore 8.72

Seals are fitted on both valves

Andrew

Posted: Sun Sep 02, 2012 8:41 pm
by johnwp5bcoupe
Thanks for the info Andrew, I have a new set of guides to go with the new valves so I want to turn down the new valve guides to take the latest seals before fitting them, and I wondered if I had to shorten them by the amount of the seal which would overhang, or is the guide the same length ?
Thanks, John.

Posted: Mon Sep 03, 2012 6:23 pm
by johnwp5bcoupe
I now understand that the older type guides will seize if used the same way as the newer type ie turning them down and using the new seals, there is a difference in the material used :? the new guides are Sintered Steel which is self lubricating! so it will have to be a new set of valve guides?????

Posted: Mon Sep 03, 2012 8:27 pm
by Darkspeed
Buy a set of bulleted guides from Real steel - a slight performance gain - not much granted but if you are doing that amount of work on the heads surely you will do the throat tweek and really maximise on the work

Andrew

Posted: Tue Sep 04, 2012 5:10 am
by demo2
I have a set of complete rocker assy's done about 500 miles so like new, i will have a look at them on the weekend if u like make sure the shafts aint rusted or anything.

Posted: Tue Sep 04, 2012 6:16 pm
by johnwp5bcoupe
demo2 wrote:I have a set of complete rocker assy's done about 500 miles so like new, i will have a look at them on the weekend if u like make sure the shafts aint rusted or anything.
That is good of you I will wait and see, postage from Australia may not be too bad? I sent a mate over there some P5b stuff inc a really good steering wheel quite rare over there :wink: