Cam buckets and cylinder head

[sulzeruk]

Hi all, does anyone have the dimensions for the bores where the tappet sits into the head. Some of the tappets feel a bit sloppy in the head so wanting to mic them to see if I need a new set or need to get them lined. Anyone have a rough cost of getting them done if I have to? I am making up a small spreadsheet with all the tolerances on it so I can print it off and note all of the dimensions down when I measure the crank, block, pistons, etc. If anyone wants a copy, drop me there e-mail address and I will forward it on,
Alasdair

[christopher storey]

If the bucket guides are worn they need replacing. They are readily available . The tappets wear but often in a subtle way , in that they deform to become barrel shaped, and then rock in the guide. It is not very easy to measure this deformity, which is probably less than half a thou, but it is probably this which you can feel . Again, the tappets themselves are readily available. Where possible, use Jaguar and not aftermarket parts, as they are more accurate in dimensions. The tappet outside diameter should be 1.3738 to 1.3742, and the clearance should be .0008 to .0019 . The internal bore of the guide should be ( reamed) 1.375 minus NIL to plus .0007. It sounds as though you are doing this without a workshop manual, which gives all this information . I advocate strongly that you get the Brooklands reprint of this as you will find it invaluable

[Heuer]

Alasdair

My car is with CMC at the moment because of noisy tappets which turned out to be a loose bucket. Cost to rework the head with new oversize buckets is ?500 + gasket set. Labour getting the head off/on is extra obviously. This is the CMC report:

[sulzeruk]

Thanks gents, I have a genuine workshop manual as well as the series 2 additional section. It looks like the buckets on the head are ropey but will get it all measured up tomorrow as I ran out of time today.
Alasdair

[sulzeruk]

Had a phone about this morning about whether to put standard or oversize buckets back in. Had a chat with Andy Rainer at Hutsons and he says that the quality of the standard buckets have been rather poor of late. So in a quandary what to do now! Have ordered the rest of the parts from him anyway. CMC get all the parts from VSE who say they don't do parts so I presume the work is subbed out to them David,
Alasdair

[Heuer]

No idea who CMC use as I never bothered to ask however it was a VSE rebuilt engine that dropped an oversize bucket after 36k miles. Suggest you give Rob Beere a call and see if he supplies the over size buckets.

Edit: Rob does at ?8.50 each: http://www.rob-beere-racing.co.uk/cams.html

[sulzeruk]

Many thanks David. I measured up the rest of the engine and it looks like the crank and mains are still standard with no wear so good news with that. Just need a polish and a clean of the sludge traps. The bores are however worn and will require a rebore as the worst is at 0.20mm. Is it worth going for slightly higher compression ratio pistons as the engine runs on super unleaded anyway?
Alasdair

[Heuer]

Not sure there will be much benefit unless you do other work to the engine. Mine is 9.5:1 and I have run it (gently) on 95 octane when I could not get super without problem. Other here might have a better view.

[christopher storey]

Pistons have recently been a problem . The AE original equipment ones are becoming very expensive even if you can get them - I paid about ?480 for a set not that long ago. Many people are using the JE pistons from Australia, and I have heard nothing against them except that inevitably there is a delay in producing them. As far as CR is concerned, I am perhaps a bit of a heretic but I like 8:1 for 3 reasons

i.it leaves you room for manouevre if you need to deck the block or skim the head - with 9:1 you can easily end up with CR in excess of 10.5 : 1 if the tolerances stack up against you

ii.The 9:1 engines always pinked even on 100 octane fuels, and on modern fuels this tendency is worsened, and you can end up having to retard the ignition which rather defeats the object !

iii.The 8:1 sets almost always produce a lovely smooth running engine

I should also tell you that my 8:1 car is noticeably quicker than my 9:1 car!

FWIW Chris

[sulzeruk]

The head is still original size so hopefully not much will need removed. The water passages all look spot on with no corrosion at all in the head at all. The block should clean up nicely as well. Have used JE pistons before and found them to be well made. Will have a look about and see what is on offer. I will be doing a bit of blue printing of the engine components as there are some rather large steps between the manifold and head which can't be doing the gas flow much good at all, ime to break out the Dremel! Will get some pictures of the whole shabang tomorrow.
Alasdair