Thread: 53J 3R and 53J 4L

I honestly don't think that sodium filled valves make any difference in the heat dissipation of the valve head. A proper tune would keep this issue at bay anyway.

really good info though tek, thanks. Found some BC valves fairly cheap, may get them with the springs and retainers as well, already got their cams.



pretty wild what these damned engineers come up with though.

couple more questions about swapping these two heads. I obviously need sr20de seals, and valves because the head I've ported is a highport de. My question really is: If I install the highport de onto my det block it will raise my compression correct? Would it be better to blend the bowl of the head a little or just get a thicker headgasket??

ttt^^

checked the head code list on the old site but neither of these heads are listed. I know my u13 head is 8.5:1 but I'm not sure if the highport head that I have is 9.5:1 or 10:1, any ideas? I'm trying to get the right headgasket for this set up.

The head shouldnt dictate the compression ratio between the engines you are mentioning in any way. The de has slightly dished pistons and the compression is 9.5:1 the 10:1 engine has higher compression beacuse the pistons have no dish they are flat topped they both use the same head. If i am not mistaken the det head has the same dish or bowl as the de, with the exception of the gtir which if i remember correctly has a slightly larger bowl area. The det has pistons that are even more dished than the det, which makes the compression lower. The gtir uses the head to get the 8.3:1 compression, it uses the same pistons as the det.
I could be wrong, as its been a long time since i looked into the matter, but thats what i remember off the top of my head.

Thanks, that's what I was hoping to hear.