Was rod bolts, now deck height question

[PeterK]

It got me thinking when someone had a water leak problem on their 4A a couple of days ago.

I had my block decked flat and my cylinder head shaved .033". When I measure the cylinders to check that they "stand proud" .003-.005", how would I correct them if the'ye now too tall? Are different thickness figure of 8 gaskets available in varied thicknesses? Also since the FO8 gaskets are fragile, I really don't want to take them on and of and on, so would I need to measure every cylinder or just one? Then what about the thickness of the forma-a-gasket that I apply to the gasket to seal to the block? I'm afaid I'm losing sleep on this one.

I am using a .030 solid copper gasket that I modified to match my ported headwith the special copper sealer spray.

btw, I am ordering ARP rod blts in the a.m.

 

[Alan_Myers]

Hi,

The usual way to correct too-tall sleeves is to mill a little off the sleeve itself. Too low is corrected by milling the top of the block slightly (requires removal of the head studs, of course).

There are different thicknesses of FO8 but only "standard" and +.005" thick. So, most adjustment needs to be done to the sleeves or the deck height on the block.

Check the sleeves stand proud by installing FO8 dry (no sealer), torquing the head down on the head gasket, then remove the head to measure the amount the sleeves are standing proud. Measure all 4 in several places around each circumference.

There are also different types of materials used in FO8: copper and steel. Copper is usually best to about corrosion (FO8s are in contact with coolant), but does compress slightly. Steel might be used to if the sleeves are a little on the low side of the usable range, won't compress, to help the head gasket seal. It's especially important to coat the steel type with sealer to help reduce rust in the water jacket.

Only a thin coating of sealer should be used, and won't effect the height of every thing significantly.

After you have the heights right, remove everything, be sure the FO8 shelves in the block and the bottoms of the sleeves are perfectly clean, and install.

I was recently chatting with someone very knowledgeable about TR engines, asking about using solid copper gaskets in case I want to reduce compression in my car a little (the head's been milled a lot). He told me he's had some trouble getting them to seal (might be the cause of that other person's coolant leak, although it sounds like powder coating on the block might be the culprit in that case).

You might check out https://www.headgasket.com/gaskets.html for info on getting a proper seal with copper gaskets.

Hope this helps!

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[PeterK]

Thanks Alan. I have copper FO8 gaskets with my Hepolite 87mm set and the copper head gasket torquing instructions. I need to use the solid copper head gasket because the chamber has been unshrouded and swept per Kastner so the sandwich style gasket that I have overlaps the chamber and can't be trimmed like the solid copper one.

But it just doesn't make sense to torque the head down. If the liners are too tall, then the head gasket would be deformed and ruined. I also wouldn't expect that the sleeves would compress, the FO8 only very, very slightly. So I think that as long as the liners drive fully home in their bores, I'll be OK taking the measurements that way.

Thanks for the advice.