Headgasket question


#1

If i end up putting an EJ head onto an EL bottom end, which would be the better head gasket to use, EJ or EF? Curious as never played with either. Goal is twin cam 660cc using the current EJ wiring, ecu already in the topless just for fun and to compare the 2 capacities.


#2

Can’t remember. Looked at it once. Just beware the oil pressure hole.

Watch the pistons to valve clearance with the (stupid) domed pistons. If you wanted revs look at a short stroke crank in the EJDE. It will rev harder in the ej block than ef block. Of course rod length is something to correct. But the long rods with short stroke mean reduced piston acceleration and this is key to pulling more revs. So same crank with longer rod length always has the ability to rev harder.


#3

Find an ef-gl and put the ej manifolds on it.


#4

But that means spending money finding one etc :wink: can get a complete EJ head from local wreckers for about $50-80 :smiley:


#5

My biggest worry you may have is the piston clearance with the ef/el pistons as they are domed and not flat or dished like the ejde or the ed. There are a few exceptions with ef series that have flat pistons but they are very few and far between. I am very interested to see how this pans out. I honestly fear you will spend that $50-80 for the head that wont work with the combo.


#6

Need to look under a piston but dome easy to remove in a lathe and have done it before and about to do it again with some 99.5mm pistons. The dome is awful for flame travel. Especially the case if looking for revs. Flat piston least likely (btwn the two) to have detonation probs and can run latter timing so higher bmep


#7

The exception to the issue with a dome piston

Combustion happens nearly all in that pocket on the top. Ignite the fuel near tdc and you get the full push down on the piston. Maybe you could pocket an efel piston? I’d never thought of that. Need to find a piston. Hmm, I do have one last ef el head and if I can find a piston I’ll see where the spark plug matches up.


#8

dammit I threw out a block with pistons before I moved. I will sing out if for some strange reason I didnt and packed them somewhere.


#9

Have just one piston here and a head. I think it would work from a material thickness and pocket position. Many benefits, including lighter piston