SR Checkout... Need some advice asap

[Kenrik]

Ok so I went to my importer today and picked out the SR20det I felt was in the best condition. We did a compression check (cold) with a little bit of oil in each cyl.

Test results came out

175175175155

Everything on the engine looks great it's one of the cleanest SRs I've seen should I be worried about the lower number on cyl 4?? Stock SR compression is supposed to be 156 on all four cold right? (without oil in the cyls)

I would be picking the engine up Monday so please reply before then


Modified by Kenrik at 12:13 PM 7/22/2006

[S13240]

It's suppose to be around 156 psi warm I think. Other than that I would be worried about #4 cyl definitely. While it's still at the shop, see if you can have them do a leak down test also.

[Kenrik]

Bump

I doubt it's the rings, it would be a valve stem seal or head gasket. and of those two more likely a valve stem seal (or the guy did not tighten the gauge in the socket enough) I'm planing on doing a cometic headgasket after everything is working well... should I really worry about it?

Yes it's lower then the other cyls but overall the engine has much higher comperssion then most used engines would...

[ILikeMy240sx]

the fact that #4 cylinder is 20 psi lower than others worry me. But the numbers themselves look okay. I would test one more time if possible to investigate further regarding #4 cyl. status. Perhaps a leak-down test on #4 cyl. is your best bet.

[AmoebAssassin]

A leaky valve stem seal would not cause a low compression number. It's either a stuck valve, busted HG, or bad rings.

[Kenrik]

The SRs use lifters right? could it be partly stuck lifter due to the engine sitting?

I mean you look in the oil cap and you can see the cams are in good condition and the metal is still silver in there... all of the freeze plugs, nuts bolts, etc... look new and there is no corosion on the engine. (the other SRs I have looked at have it..)

hmm...

[ILikeMy240sx]

lifters might have air in them (common if SRs been laying on its side and such) in that case you would have to bleed them but they dont have anything to do with compression nor your valve seals...

Id do the compression test again..

[Kenrik]

Blah this sucks... will I ever find a good SR?

[FAST-DATSUN]

oil in the cylinder rases the compression and mask ring problems, it should be check with out oil, the best is after running for about 15 minutes...