K100 Head Studs
Turbo Mini Forums

I was planning on using the three existing head studs as recommended by the SC manual.

However, on the small bore the slight missmatch of the bore centrelines causes a significant overlap.



The head could do with moving over by about 2.5mm.

I was planning to sort this with a 1.0mm offset of the bore in the north/south direction.

However, I recently saw a photo of a dry decked block where the three studs had been moved by plugging and re-dirilling.

Is anyone else planning or have done it this way?

If I do it this way then I can offset the bores further in the east/west direction which would help unshroud the exhaust valves on cyls. 2 & 4.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

i was at the machine shop the other day and we had a similar discussion. not sure what would happen with regard to the cam pulleys lining up etc.

what we said for now was we would put a chanfer on the top of the bore to stop hot spots and then put "pockets" in. tbh though they will be more like a radiused lip.

i wouldnt have thought that this would cause a problem with the cam pulleys because as long as they stay inline on the y axis then you should be able to move them on the x-axis enough to get the clearance you need.
or am i totaly wrong?

it sounds like a very good idea to me, a good way of getting a better match to the bore spacing.

My main concern was the plugging and then re-tapping of the stud holes.

As far as the cam pulleys is concerned, moving the head a couple of millimeters towards the front of the engine should not pose a problem.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

ahh i see move it forwards!!! i thought you meant moving it more towards the water pump end. i dont see why it would be a problem to redrill them as that is what you have to do on a couple of the others anyway.

How about plugging the head holes, and re-locating those?
Or at least elongate the middle three?

This made sense when i looked at the 8v - not so much on the 16v though

One thing about doing it that way Dave, is the locating of the head. Id be inclined dowel the head in that case

Sprox,

It turns out that the photo I could not find was of your block. Hidden deep in your EFI forum.

Did you do it that way for the same reason?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I did indeed, i wanted to get the head chambers dead centered over the cylinders. Optimising what i got rather than clearance isues.

Did you use 3/8 BSPT plugs? and then re-drill?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I moved the front head studs on mine

Team Racing

looks like i will be calling the machine shop this morning!!! hopefully they havent done much more to it!!

Edited by Sprocket on 10th Mar, 2008.

Thanks Sprox. Great Stuff.

Makes more sense than shifting the bores towards the studs.

Edited by Paul S on 10th Mar, 2008.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I used 3/8 bspt plugs for my plugs, cast iron bar just to be safe on the thermal expansions. Mine overlap on the back three between plug and block, i can't see a problem with it personally and our engine builder for work said it should be okay.