removing cylinder head. streched bolts? head skim?

[bombz4]

am i going to have to buy new bolts or are they re-useable? as some engines have to have them replaced.

what difference will skimming the head make on performance? its cheap to do and while its off!? im just abit concerned itl cause problems and wont last as long with raised compression. anyone ever done it?

 

[Batch]

I had a couple of thou's milled off my head and used the same head bolts no problem.

although a few thou's ain't all that much really. raised compression will obviously add a bit of strain on the internals but the K10 blocks are fairly sturdy so it shouldn't be too much of an issue...

 

[bombz4]

any power differene from it tho?

 

[Batch]

not really, accelleration a little, but not much.

On a 55bhp engine you aren't gonna feel all that much difference from a 'few' mill's off the head. Best to get a re-conned and re-jetted carb, re-profiled cams, manifold (both preferably) and full S/S system. If you get these going and then get the head gas flowed and ported/polished you should be looking at a good hike in power.

Maybe consider a mapped ignition system and twin carbs for a quick high power fix! (would be totally un-driveable and in-efficient though! )

 

[Andrew]

A mill is 40 times bigger than a thou...

 

[AMY]

Hi Bombz, I'm selling (one of) my k10 if your interested, the body work isn't great, but It's fitted with a 1.2 engine and 5 speed box I rebuilt it about 3 months ago. The head has been skimmed back 45 thou and has triple angle valve seats and been ported. the inlet and exhaust manifolds have been de burred and port matched. It is fitted with a rebuilt 1.2 carb which has been setup. it also has new rotor cap, arm plugs etc and has had all the gaskets and valve stems replaced.
I was told that the engine has only covered 50k, I can't confirm this, but it doesn't smoke at all and pulls real strong. The bores still had the original cross hatching so it can't have done many miles. The car still has 10mths mot and a few months tax and a few extra's, rear spoiler etc. I don't want much for the car it might work out cheaper to transplant everything over to your car, also i'm just down the road from you, I'll take you for a spin if you want, you'll be amazed how much quicker it is than standard!! Let me know

Forgot to mention, it has a new complete clutch and timing kit (belt and pulleys)

Cheers

 

[Ed]

AMY with so much taken off the head did you do anything about putting the cams back in timing?

 

[Andrew]

I can't remember the diameter of the top pulley on the cam belt, but it is between 100mm and 150mm, with a 45 thou skim (1.7mm), you are looking at between 1 and 2 degrees timing variation.

 

[Ed]

which is quite significant really.

 

[AMY]

Ed, I tried to get an offset key, but I don't think there is anyone out there who makes one. I turned the engine by hand to check for interference using blue tack on the piston crown, there was a good few mill of clearence. As for the cam timing there isn't much I can do about that unless I can make an offset key or modify the cam gear, but it runs spot on anyway. Even with the compression raised that much my tuner was still able to raise the base ignition timing to 8 deg btdc. Am I correct in thinking my cam timing will now be advanced?

 

[Andrew]

Cam timing will be retarded... unfortunately because it is a single cam engine, both exhaust and inlet will be retarded which tends to lead to loss of power across the range.

 

[AMY]

Yeah I kind of figured that after I had posted, It still goes like a rocket anyway, I could probably drill another dowel hole next to the standard one and elongate the bolt holes. Assuming that it is around 2 deg retarded at the moment if I could drill another hole this would probably advance the timing by 4 or 5 deg so 2-3 deg more than standard which should give more power. but anyway i'm selling the car so if anyone wants a good engine/car that has had a lot of work done and a lot of money spent please let me know. I'm only selling it as I have a new super s which I'm going to spend the money on instead. I'v got bigger plans for this one!!!

 

[bombz4]

sounds nice amy but ive got my superS head off on the driveway at the mo (f***ing valve!)and my super still mashed up in front of that,(my rents are goin nuts) sounds like a nice motor tho. if i can fix and get rid of my super and you still got it id definately come and have a look. out of question what compression are you running at? (if you know) and werd you get it ported and polishd? my heads off so would be a good time to get it done.
+ shocking result against barnsly! i went to the brentford match