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View Full Version : Can sr20det rod caps be installed backwards??


Dsmguy1993
07-09-2020, 02:23 AM
hello so I rebuilt a red top sr20det recently and installed it in my s13 driveshaft hooked up everything hooked up minus a turbo fuel injectors air intake and fmic. one thing that came to my mind today after watching an ej20 rebuilder was can our rod caps be installed backwards? I remember lining up my rod caps with the notches on the same side is that the right way to do it or am I possibly screwed? the motor spins over by hand easily it feels good and after I timed it and spun it sounded like it made compression just like normal.

jr_ss
07-09-2020, 07:33 AM
Rod caps should be installed as they can from the factory. Also to note, torquing rod bolts isn’t the only step you should complete. Rod bolts stretch is vastly more important, because torque wrenches can be erroneous. Please see both links below.

https://www.realstreetperformance.com/blog/tech-tip-4-bearing-tangs-and-rod-cap-direction

https://www.google.com/amp/s/blog.k1technologies.com/how-to-install-connecting-rod-fasteners-the-right-way%3fhs_amp=true

S14rebuild
07-09-2020, 09:33 AM
No!!! Rods and caps go a certain way..they are numbered stamped, both numbers to one side

https://www.google.com/search?q=connecting+rods+stamped&tbm=isch&ved=2ahUKEwi9j6fAscDqAhUQRFMKHY_wD_kQ2-cCegQIABAB&oq=connecting+rods+stamped&gs_lcp=ChJtb2JpbGUtZ3dzLXdpei1pbWcQAzoFCAAQzQI6Bwg jEOoCECc6BAgjECc6BAgAEEM6AggAOgQIABADOgUIABCxAzoEC AAQHjoGCAAQCBAeOgUIIRCrAlCevQFYmfYBYMv3AWgBcAB4AoA BvQGIAcYlkgEEMC4zNZgBAKABAbABBQ&sclient=mobile-gws-wiz-img&ei=fCoHX73hHJCIzQKP4b_IDw&bih=678&biw=412&prmd=sivn#imgrc=5ZhaZT9PJ4CmMM

Like soooo

Dsmguy1993
07-09-2020, 10:33 AM
Oh I see yeah without taking it apart I have no way at this point of knowing if thats done correctly or if its not done correctly. the only way I can see that happening is pulling apart everything to check the rods are oriented correctly because you would need the cylinder head off also at that point in case you had to remove a rod cap.

Dsmguy1993
07-09-2020, 11:46 AM
Yeah when I assembled the shortblock I just matched up the bearings by that little tab or notch they all share I put them on the same side so they match up. So I would install a new bearing in the road cape and install that cap onto the connecting rod with the notches facing eachother. used plenty of assembly lube spun the engine by hand seemed to spin over just fine did not notice any abnormalities.

S14rebuild
07-09-2020, 12:07 PM
Why would u have to pull the cylinder head?

Dsmguy1993
07-09-2020, 12:21 PM
Well I usually tap the connecting rod bolt lightly with a flathead just to move it a little bit under the journal but if you dont take off the cylinder head yo cannot remove the piston in case the connecting rod gets a little bit mis-oriented while you remove the caps. or maybe you can remove the caps carefully and dont need to worry about this? Either way I think I did mine right I faintly remember in my memory bank while assembling the motor I made sure the numbers matched up the notches match up too I think they only go on correct one way. the motor spun over really easily by hand. I was even thinking about blocking the turbos oil feed filling up the sr with oil and cranking it just to listen and see if it turns over nicely and makes good oil pressure?

S14rebuild
07-09-2020, 12:30 PM
Theres no reason to move the head...

Remove lower and upper oil pan...(remove motor mount bolts to halp lift the motor up to gain clearence to get upper pan out)

Now u have full access to the rods.

Spin crank to rear 1 rod at a time..verift the cap is backwards. Remove both nuts and flip the cap. Torque and repeat.

If changing bearings do the same, but tap the rod up by the stud with a brass hammer or wood dowel(not to damge threads) pop the bearing out. Reinstall upper bearing half and pull the rod back down, make sure the bearing is seated properly in the rod. I stall bottom bearing into the cap. Then install bearing and cap in THE PROPER ORIENTATION. torque to spec and reinstall pans, mounts and oil.

S14rebuild
07-09-2020, 12:32 PM
Just incase here-

https://www.realstreetperformance.com/blog/tech-tip-4-bearing-tangs-and-rod-cap-direction/

Dsmguy1993
07-09-2020, 01:07 PM
yeah that sounds very easy well not very easy but not too hard either for sure. I can definitely do that do you jack it up at the transmission or just put a hoist on it to gain clearance for that upper pan? Also since im gonna have to reseal it obviously my next question would be like is it hard to reinstall the upper oil pan nicely without smearing the rtv? I know it has little dowels so im sure those help. Last thing though if a cap was backwards theoretically would the engine still spin by hand or even just crank without starting?

S14rebuild
07-09-2020, 01:15 PM
Just un bokting the motor mounts and jacking up the motor, should give you plenty of space, but if needed u can drop the fro t subframe some aswell. That should allow enough space. As for the rtv, just take ur time ,gain enough clearence and ull get the pan back on and sealed up fine. Its tight but doable.

As for the cap, that i dont know, ive never put them on backwards and torqued them down and see if it spins. For all we know u installed them properly..but that have to be on u and ur memeory. Cant speak on something i didnt do. Thats why engine building is a precise job. Has tobe 100% right.

If your really not 100% sure.


Acually im not 100% sure but i think u can just drop the small oil pan, pickup and large tray and u can see #1 cylinder.... look up in there and that might save u fro. Tearn it all down(that is if u put the caps right) just to check it

jr_ss
07-09-2020, 01:22 PM
DSM- please don’t take this the wrong way, but it doesn’t appear that you have the knowledge or know how to complete this task as it should be done. I strongly suggest you put a stretch gauge on your rod bolts too, otherwise, you’re going to inadvertently vent your block.

Watch the video I linked in the second post, it answers your question. If you aren’t sure how you assembled them, remove the components and verify. If you didn’t number rod caps to rods, then it all has to come apart, so the rods can be machined to match each other.

Pull the shit back apart and put it on a stand. It’s far easier to check this way.

Dsmguy1993
07-12-2020, 08:22 PM
agreed its coming back out and getting verified the caps go to the same rods so im gonna check their orientation and make sure everything is good before putting it back in the car. Already got the trans drained driveshaft out wiring disconnected shes coming out tomorrow. i wonder do I take off my clutch to put it on a stand? Or can I throw it on the stand with the clutch(preferrable) as im running arp flywheel bolts but prefer not to remove the tty bolts.

S14rebuild
07-12-2020, 08:26 PM
Clutch n flyweel off, plus ud need that off to remove crankshaft to check bearing clearences...

Dsmguy1993
07-14-2020, 02:14 AM
yeah I got the sr20 pulled out clutch off flywheel off ordered nissan orange gasket maker 999mp as they call it. tomorrow its going on an engine stand and then Ill take a look at it.

jr_ss
07-14-2020, 07:56 AM
yeah I got the sr20 pulled out clutch off flywheel off ordered nissan orange gasket maker 999mp as they call it. tomorrow its going on an engine stand and then Ill take a look at it.

Check your rods, there may be numerical marks on the rod and cap to mark the married pair. My Eagle rods have these markings, even though I marked them as well.

Dsmguy1993
07-14-2020, 01:11 PM
thats exactly why I pulled it is to check it basically I already have it chilling in my engine stand I took the lower oil pan off I cannot seem to get the upper oil pan off I hondabonded it on and its like stuck on I think I gotta run two bolts through it to break it loose but I dont know what size those bolts are to tighten it down and it takes upper oil pan off anyone know? and yes srs do have married rods and caps one number denotes the bearing grade usually 0 or 1 the other number is cylinder number so 1-4 so just remember like if the cylinder number is 3 then on the rod cap 3 would face 3 on the rod and the other number 0 or 1 should face 0 or 1 easy to understand.

S14rebuild
07-14-2020, 01:46 PM
No he meant the cap is stamped 1 and rod stamped 1
2-2 3-3 4-4. There matching sets n numbers go on same side....were NOT talkn about bearings


https://motoiq.com/ultimate-sr20-rebuild-guide-part-1-the-teardown/7/

Dsmguy1993
07-14-2020, 02:35 PM
I know mate thats exactly what im saying that the number is stamped on the cap and on the side of the rod itself as well and the caps number and the rod numbers should match. by the way upon pulling it my cylinder number 1 cap was indeed on backwards its a really good idea I checked it before cranking this motor I had a feeling itd be a good idea.

S14rebuild
07-14-2020, 02:36 PM
Ohhhhh mannnnnnnnn

Dsmguy1993
07-14-2020, 04:44 PM
im amazed honestly goes to show you really gotta check and make sure its okay or take pictures of it

S14rebuild
07-14-2020, 06:15 PM
Was taught dissasembly is just as important as reassembly. Gotta mark and document EVERYTHING when taking motors apart. Carefull of direction of parts, bolt lengths, and be organized!

Dsmguy1993
07-14-2020, 07:23 PM
Just out of curiosity can the main caps be installed backwards? i have their numbers facing the same way in the correct order from what I can tell.

S14rebuild
07-14-2020, 07:44 PM
Mains go 1 starting at the oil pump and go back towards the rear main seal.

Like

Oil pump

1
2
3
4
5
Rear main seal

S14rebuild
07-14-2020, 07:49 PM
You should download the fsm.and review the engine section of it..all this info is in there.....

jr_ss
07-16-2020, 02:36 PM
The main cap should have the stamped number on the intake side of the motor. Or the right side if you’re standing at the oil pump looking at the rear.

Kingtal0n
07-16-2020, 05:19 PM
never take an engine apart unless you have everything ready to re-assemble.

The mind forgets very quickly and soon you just have a pile of parts and lack of willpower and memory to get the job done

Dsmguy1993
07-16-2020, 10:21 PM
finished checking my engine today and re-assembling it I removed my girlde to double check my main caps props to whoever said its on the intake side mine were on the intake side already heres a photo if you zoom close you can faintly see the numbers sorry I was working on the sr at https://i.postimg.cc/ZR4bLLFX/253-BBE1-E-E90-C-4206-927-B-F09112-B1-E0-B1.jpg

Dsmguy1993
07-16-2020, 10:24 PM
here are pics of the rod caps on correctly you may need to zoom in for #1 its shadow is hiding it slightly.
https://ibb.co/cD2BN0R
https://ibb.co/BB5zP0S
https://ibb.co/HY74Rs1
https://ibb.co/q1TtTBp
https://ibb.co/x5tgt1Y