sr20det head work - questions / concerns

[opponheimer]

I apologize for naming the thread title as I did, this doesn't focus on performance head work or anything like that. Just rebuild.

Mechanically over - revved my sr to approx 10500rpms a few days ago (a bad miss shift), bent two valves, nicked the pistons up, and cracked 4 rocker arms from the lobes of the camshafts crushing them into the inside castings of the head. I have parts from another sr head lined up. I do plan on reusing this head, with good cond. parts though.

I just need

1 intake valve
1 exhaust valve
intake valve seal / exhaust valve seal

and maybe valve seats.


My questions are:

1) Do sr20dets have valve guides? If so I do not see any, I believe the valve seal is the guide, am I correct? (I also did not see a part number for guide, anywhere listed on sr faq archive.)

2) Is it totally necessary to retorque ARP head studs after heat cycling the engine? How many heat cycles are necessary? Will I be able to get to the arp nuts without removing the cams?

3) How exactly do you "reload" the timing chain tensioner so that it is ready to spring back into action when i lift the little hook arm off it?


Thank you guys for any input you provide me with! :w00t:

[Sileighty_85]

A1) Yes they have valve guides, No the Seal is seperate the Guide is located underneath the Seal.

A2) See ARP Secs. No you have to remove the cams, maybe you can get to them with a U-Joint Socket Shallow socket, but you might as well as take off the Cams

A3) it springloaded with a latch so hook it, the pop it in in the correct direction and your done. It un latches by itself

[fliprayzin240sx]

If you damaged the head that badly, check the valve seats and make sure theyre all good. I highly doubt they're still good, Most of the people I know whos done something like has nicked a good chunk off one of the seats. No way you can fix that, your head is probably junk considering how much damage you did to it. I wouldnt recommend you to re-use it.

[opponheimer]

All cam bearing surfaces look fine, and valve seats look fine and don't appear to have any scratches/scrapes etc. on them. I would need new guides and seals def. I considered getting another head but I do think I'm safe with reusing the head w/ replaced parts. It'd be nice if I had a photo.