Ford built them with steel shim gaskets and specified the compression ratio on that basis. If memory serves 239's have something like 7.2:1 comp. ratio so composition gaskets will lower that to below 7. This is just giving away some power and economy. The reason for comp gaskets is that they do not have to be retorqued like the shop manual calls for after initial warm up. The shop manual never anticipated comp gaskets. As I said if the block and heads are flat use NEW gaskets and steel shim would be my personal preference.

Note the beeds on the shim gaskets deform to fill any minor concavity and the gasket sealer just fills in any minor machining grooves etc that the gasket itself can not deform into. But they can not do it twice once they are flatened they are done so I would be extremely reluctant to use any gasket over again. BTW I have always used brown gooy permetex but others use paint or ?

Doug T

The Highlands, Louisville, Ky.

54 country squire, I ordered bolts. I don't have any experience with studs. I've seen a lot of studs on big horespower engines and I guess you are less likely to strip the threads in the block with studs but I just went with what I am familiar with.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

I did this just yesterday. Timing pointer lined up with zero on the pully. Do both valves at #1. Twirl pushrod while tightening stud. When it's too tight to twirl, stop. Back the stud 1/4 turn, tighten locknut.

Turn crank 1/4 turn, do the valves at #5. Turn the crank 1/4 turn, do the next set of valves following your firing order. Continue until all 8 sets are done.

  Dennis in Lititz PA

My last set of gaskets were ROL gaskets. They felt sticky to the touch and the instructions said to not put anything on them.

  Dennis in Lititz PA

hello doug t, thanks for the info., I will be sure to check the rocker arm surfaces, also is your only reason for recommending the steel shim gaskets comp., loss? this is a daily driver wagon in the summer and I just want it to be dependable. one other thing, have you ever re-used the steel shim gaskets? my engine builder says they used to run an old hemi and re-used the steel shim gaskets several times without problems, thanks again, doug.

hello dennis, my engine is an ebu, which I believe is the early version, I do have the correct gaskets. whats your take on spraying the composites w/ copper spray? thanks, doug.

hi mark, thank you for your input, when you say you ordered a set from mummert do you mean studs or bolts? thanks, doug.

thank you for your input, although not an expert I agree with you. sometimes I think race builders have a little different take on things?

If they are not flat there is a formula used based on # of turns outwards once the arm is in contact with the pushrod.I believe it is 1/4 of a turn.Anybody know for sure? Also works with rocker arms hat have a flat pad in contact with valve end.

  

I have just posted for sale 3 steel shim head gaskets which this thread reminded me that I have with no expected use for. There are pictures with this posting also showing the differences with the normal y block gasket which are considerable. If it were mine to do I would go with steel shims if the heads and block are flat because the composite gaskets cost compression which is in short supply in a 239 anyhow.

Re valve adjustment be sure that the rocker arm surfaces that contact the valve stems are flat, this is a wear point that is often overlooked by non yblock specific mechanics. If they are not flat the valves will be noisy because they will not be adjustable with feeler gauges.

Doug T

The Highlands, Louisville, Ky.