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View Full Version : SR20DET Bearings/Rings, what’s your preference?


snow hawk
12-22-2017, 02:36 PM
Hey Zilvia;
I’m going to be rebuilding this SR I have in my shop. Just curious as to what my SR people recommend for bearings and rings? I’m going to do stock rods/pistons, so I was going to go with OEM, but I figured I’d see if anyone else would throw their two cents in on what may be a better option.
I was going to go with Manley rods/maple pistons/king bearings, but I changed my mind and just going for stock at this point.

Thanks in advance!

RalliartRsX
12-22-2017, 03:05 PM
King or OEM for bearings. ACL has shown to have significant variance in sizing

Kingtal0n
12-23-2017, 12:57 PM
I can't think of anything better than OEM for an OEM rebuild. If you can get 50k or 100k out of a rebuilt sr20det with stock internals, then you can move on to the forged stuff. Problem is you will be 5-10 years older and maybe not care about cars anymore or need to sell it before then. This is a fundamental problem with building a forged engine for the first time, and part of the reason the failure rate seems so high. First and second time engine builders using aftermarket parts often neglect aspects/measurements in places that OEM parts would not have been as likely to need.

In other words, you can follow FSM to perform an OEM rebuild, as long as it is clean it has a good chance of success IMO. Where following FSM for an aftermarket forged bottom end could be disastrous. There are no "guidelines" for perfect forged bottom end sr20 engines (unless you make one yourself like the "pros" whom own machine shops etc...) you only get some basic measurements to take (like a recommended piston/wall clearance) and the rest is up to you to figure out what else to measure and how you are going to 'correct' those measurements....

gaz_moose
12-24-2017, 08:44 AM
^^but most engines will be getting rebuilt due to wear^^ so things like OEM piston to wall clearance will be out the window. same with trying to spec bearings off the numbers stamped on the crank/block.

snow hawk
12-24-2017, 09:11 AM
Thanks for the insight fellas!
My plan with it is to get dropped off at the machine shop for a full Work-Over. The machine shop is going to hot tank the block, ball hone, check deck, gap my rings, (might have them assemble the short block for shits, I work at a shop but I barely have any time as it is) disassemble and hot tank my head, valve job, check surface and get a nice fine RA. Just figured I’d see if people had better results with aftermarket bearings and rings than OEM.
I was going to go with a built bottom end while I have it apart, but my bank account said chill lol.
Plus, I’m tired of missing track time.
Just figured I’d see if there was any winning combo other than OE. I’ve owned KA/KA-T(700hp)/4.8 LM7/5.7 LS1 so I’m not very familiar with SR’s as far as what a winning combo is.


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Kingtal0n
12-24-2017, 01:02 PM
^^but most engines will be getting rebuilt due to wear^^ so things like OEM piston to wall clearance will be out the window. same with trying to spec bearings off the numbers stamped on the crank/block.

I've yet to see an sr20 engine with 150k or 200k miles that the OEM stamped bearing and piston/wall was wrong because of wear. The FSM probably gives you some great ideas how to handle this also, if it happens, I've just never seen it happen. I also don't consider this a big issue since you can always go one size up or down in the piston (from another cylinder with a different "stamp") or even buy a brand new OEM crankshaft if you needed to. I've also seen 200k mileage motors come apart looking brand new, that just needed a hone/ring and oil pump, and I re-used almost everything. I'd rather do all the work in my own clean room than have a machine shop touch anything on an sr20. Everytime I've sent an engine to a machine shop they screwed it up royally. I had them come back with:

1. air in the lifters (apparently, Honda engines get "bled full of air" or something, and machine shops that don't deal with sr20's will do this terrible thing to your sr)
2. wrong deck/oil pump shape, leaking massive amounts of oil in the front of the head I see in 90% of rebuilds
3. left out bolts and loose bolts, I've found the two long head bolts missing before, and two rear main/oil pan nuts loose.
4. wrong camshaft timing which may lead to bent valves (I got lucky once)
5. Too much piston/wall clearance (seems like machine shops are over zealous and give extra thousandths for no good reason)
6. out of round bores after machine work due to improper deck-plate/clamping force on the deck or mis-used hardware

And those are just thing things I was able to catch

kyral
12-26-2017, 01:26 PM
Nippon NPR pistons with rings is good quality and very affordable

bearings id go with either king or mahle clevite

TheRealSy90
12-26-2017, 04:10 PM
The crank bearings are a softer material than the crank. Unless it spun a bearing and damaged the crank there should be no significant wear to the crank journals that would make the oem bearing size stamps incorrect. OEM bearings all the way, get the sizes recommended for your crank and block. The sizes are stamped on the components.

sidewaysil80
12-26-2017, 05:25 PM
I am getting ready to rebuild an SR with blown ringland. I am using OEM .20 over pistons (FSM has specs for them) and rings. I will be using OEM main and rod bearings that I'm going to measure with calipers/bore dial to confirm stampings. I will be replacing main, rod, and head bolts with new OEM hardware. I am however upgrading to a Tomei head gasket. I have sent the oem rods off to be checked and shot peened for insurance. The reason I'm leaning heavily on OEM components is that I am only going to boost 17psi from S15 Spec R turbo and wanted the reliability of a factory motor. By following the FSM and using it's specs I remove a lot of variables and guesswork. Since this is my first motor the FSM is sort of like training wheels for me and I feel a lot comfortable referencing it as opposed to several manufacturers of separate components. I ordered all of my hardware and internals through amayama.com and they shipped very quickly and were priced MUCH cheaper than stateside (surprisingly).

All of my research on the subject pointed to oem bearings being superior to acl/clevite (for the sr20 that is) due to the sizes and specs of clevite/acl compared to what the factory recommends.