Hey yall,

I had my head resurfaced and they had to cut 0.015" off to get it straight again.The OEM maximum resurface limit is 0.2 mm (0.008 inch) based on a height of 105 mm (4.13 inch).
I know I can restore my hight if I use a thicker head gasket but am I going to be OK with the oem head gasket and have a bit more compression? Am I going to have valve contact problems? Dose anyone have any experience with this?

Thanks for any help!

 

I think youre ok with .015", it will make piston to valve clearances tighter, but still ok. You should clay the engine to make sure everything will clear. Or if you want to be on the safe side get a cometic gasket thats .007" to .008" thicker than the OEM gasket.

 

Thanks for your reply!

I would like to use an OEM head gasket. Do you have first hand experiance with this on an F20C motor? Is this not uncommon? Do you know if there will be any significant probs with cam timing ect?

 

I dont have a lot with stock set ups, mainly with aftermarket ones. These are interference engines, and fairly sensitive to timing, so you do have to be careful when modifying them. The biggest thing is the Timing Chain Tensioner, if it does happen to fail you are more likely to have the pistons whack the valves, when you tighten up the clearances.
I have taken .040" of a head but this was an engine that had aftermarket cams, valves, rods and pistons.
However when you take off material from the head or block you may gain static compression but you retard the timing, because timing chain is still the same length. And the retardation will probably offset the increase in compression. That is why the K engines have a broader torque range because of the VTC on the intake gear. Cam timing is more important then compression ratio. Every 1.0 point in compression gain is roughly 4% in power, but cam timing can be worth a lot more.
I hope that helps

 

With the high compression and moderately aggressive cams in the f20c, you'd be best off claying the motor since you cut off about twice the recommended amount, or if you want to play it safe and don't want to clay the motor, then go with a thicker HG as mentioned.

 

I think i'll go with "better safe than sorry" and order the thicker HG. That way I don't have to worry about cam phase or valve clearances.

Thanks again.

 

If it is a stock engine just be safe and run a little thicker gasket. If you are building a new motor and can check clearances, .015 isn't much off. We frequently take .030-.060 off to get compression up, but there are some things that need to be worked out at that point.

 

To update;

I got this engine back together and I used a slightly thicker gasket than OE. (.036" Cometic). The cam timing as actually advanced slightly from milling the head due to the idler gear/cam chain sprocket turns opposite of the cam gears. Car feels great. If I take It to the dyno any time soon i'll have before and after sheets to post.

 

on the head, there are 3 places to help you mesure how much is too much milling

this video show you how to mesure it on the block
http://www.youtube.com/watch?v=vkpd1...81655&index=39