Need advice on engine rebuild - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

AndrewS13 · 02-12-2020, 06:40 PM

I just bought a 1993 240sx with a sr20det swap. Here are the specs that I know of-

ISR 3871 turbo
Built/ported head 7500k miles
Built block -cp pistons, eagle rods, new crank, tomei procams 7500k miles
Stock ecu
Stock injectors
Stock maf

The problems I've noticed so far- rear main seal leak, running super rich, boost leaks, an exhaust leak I havent tracked down yet, antifreeze in the oil, and a bunch of oil in the inlet of the turbo and intercooler.

Since theres antifreeze in the oil, im thinking I'm going to have to redo the headgasket. And since I have to get to the rear main seal anyway, I figured I'd just pull the engine. This is only my 2nd turbo car and 1st rwd and I could use some advice as to what else I should replace while I have the engine out?

Parts I already have-
Apexi pfc with datalogit
Enjuku 750cc injectors
Z32 maf

Obviously I need a head gasket and a rear main seal, but am I best off getting an entire engine gasket rebuild kit? Or are there just a few that are important? Thanks.

S14rebuild · 02-12-2020, 07:06 PM

Pull motor out, invest decent $ into proper measuring equipments and check all tolerances and spaces of the motor..
Go from there

Or find a machine shop that has years of knowledge/experience with your specific motor and have them tear down the engine and check everything and go from there...

Either way be prepaired to pay and invest $

jedi03 · 02-13-2020, 08:27 AM

also get the full engine gasket set...this should include the DP gasket iirc, get a seal for good (stupid thick gasket at autozone, think permex? makes it...have used them and they are great!) for the elbow to DP, measure and put some new bearings in it...but like stated above would be good to bring to machine shop that can do it and they should help do it correctly...would recommend someone who works on race engines as a lot of the others tend to mess things up...

AndrewS13 · 02-13-2020, 04:05 PM

Quote:

Originally Posted by jedi03

also get the full engine gasket set...this should include the DP gasket iirc, get a seal for good (stupid thick gasket at autozone, think permex? makes it...have used them and they are great!) for the elbow to DP, measure and put some new bearings in it...but like stated above would be good to bring to machine shop that can do it and they should help do it correctly...would recommend someone who works on race engines as a lot of the others tend to mess things up...

When you say DP gasket, are you talking about the downpipe? And put new bearings in what?

So far my plan is to pull engine, inspect, and rebuild with a gasket kit. Thoughts on this one?
https://www.enjukuracing.com/product...20det-s13.html

I'm also going to rebuild the turbo as there is a decent amount of shaft play. I can just use a rebuild kit for a gt2871r right? Im pretty sure they're essentially the same turbo just ball bearing vs journey bearing.

This isn't my first turbo engine rebuild and I'll have help. Its just my first sr20 and s chassis

TheRealSy90 · 02-13-2020, 04:47 PM

Quote:

Originally Posted by AndrewS13

I'm also going to rebuild the turbo as there is a decent amount of shaft play. I can just use a rebuild kit for a gt2871r right? Im pretty sure they're essentially the same turbo just ball bearing vs journey bearing.

Ball bearing CHRA's aren't really rebuildable.

AndrewS13 · 02-13-2020, 05:00 PM

Quote:

Originally Posted by TheRealSy90

Ball bearing CHRA's aren't really rebuildable.

So do I have any options here other than getting a new turbo? If I need to get a new turbo am I best going back to stock turbo and keeping stock ecu set up? Im only looking for 300-350hp

mechanicalmoron · 02-13-2020, 05:23 PM

Does the turbo made bad noises, or turn hard, or have any scoring or fin damage?

Not saying cheap out on a turbo and risk your motor eating it, but oil in the intake and being able to wiggle the (smooth and nice feeling, unchipped) compressor wheel a bit is par for the course with any vehicle with a turbo.

If you need a head gasket you need a gasket kit or the balls and experience and materials to make and fake the gaskets you need. If you've rebuilt motors you should have some sort of feeling about all these questions you're asking...

S14rebuild · 02-13-2020, 06:25 PM

Worryn bout a turbo when the motor has issues.....

AndrewS13 · 02-13-2020, 07:41 PM

Quote:

Originally Posted by mechanicalmoron

Does the turbo made bad noises, or turn hard, or have any scoring or fin damage?

Not saying cheap out on a turbo and risk your motor eating it, but oil in the intake and being able to wiggle the (smooth and nice feeling, unchipped) compressor wheel a bit is par for the course with any vehicle with a turbo.

If you need a head gasket you need a gasket kit or the balls and experience and materials to make and fake the gaskets you need. If you've rebuilt motors you should have some sort of feeling about all these questions you're asking...

Thanks. Definitely more play than the t25, 14b, and 20g turbos i've had. And wayyyyyyyyyy more oil EVERYWHERE. I have a feeling there's a bunch of engine blow by, going to do a compression test to confirm. I just don't trust this turbo so i was asking if they were able to be rebuilt like my td05... I think the turbos still good but I don't trust it long term especially on a freshly rebuilt motor.

AndrewS13 · 02-13-2020, 07:42 PM

Quote:

Originally Posted by S14rebuild

Worryn bout a turbo when the motor has issues.....

Just trying to plan my rebuild. Thanks for the input.

jedi03 · 02-18-2020, 02:18 PM

look at twisted motion for help on lower cost for turbo...tear it down, measure it correctly and put it back together!

AndrewS13 · 02-18-2020, 03:31 PM

Quote:

Originally Posted by jedi03

look at twisted motion for help on lower cost for turbo...tear it down, measure it correctly and put it back together!

Thanks. Engines ready to be pulled and should be on a stand this weekend. I have the s14 sr20det FSM downloaded so i'll most likely just do the measurements myself. If anything looks odd I'll be taking it to a local machine shop that did work on my 4g63 to check it out. Couldn't find anyone that has a lot of experience with sr20s.

I definitely think the turbo can be salvaged at least temporarily until im ready to upgrade to a bigger turbo. Thank you for the twisted motion tip. I'll look into them.

jedi03 · 02-19-2020, 09:43 AM

if you have a good micrometer like https://www.grainger.com/product/2ZT...200219162722:s and know how to use it definitely! I would also suggest a bore guage (think that should be able to measure the crank journals too) so that you can tell if the block has had the bottom end machined as well...if it didn't spin a bearing or the bearings don't look to worn sometimes you can get away with just measuring the bearing and get a same size set...also don't skimp on the replacement of wear parts...they aren't that expensive, also would suggest re-do freeze plugs, and actually remove them, not just push them in...its been recommended to me to use bronze as they don't weld themselves in like the steel ones do

02-12-2020, 06:40 PM	#1
AndrewS13 Leaky Injector Join Date: Feb 2020 Location: Omaha, Nebraska Posts: 80 Trader Rating: (1) Feedback Score: 1 reviews	Need advice on engine rebuild I just bought a 1993 240sx with a sr20det swap. Here are the specs that I know of- ISR 3871 turbo Built/ported head 7500k miles Built block -cp pistons, eagle rods, new crank, tomei procams 7500k miles Stock ecu Stock injectors Stock maf The problems I've noticed so far- rear main seal leak, running super rich, boost leaks, an exhaust leak I havent tracked down yet, antifreeze in the oil, and a bunch of oil in the inlet of the turbo and intercooler. Since theres antifreeze in the oil, im thinking I'm going to have to redo the headgasket. And since I have to get to the rear main seal anyway, I figured I'd just pull the engine. This is only my 2nd turbo car and 1st rwd and I could use some advice as to what else I should replace while I have the engine out? Parts I already have- Apexi pfc with datalogit Enjuku 750cc injectors Z32 maf Obviously I need a head gasket and a rear main seal, but am I best off getting an entire engine gasket rebuild kit? Or are there just a few that are important? Thanks.

02-12-2020, 07:06 PM	#2
S14rebuild BANNED Join Date: May 2019 Location: Florida-FAIL Posts: 2,495 Trader Rating: (8) Feedback Score: 8 reviews	Pull motor out, invest decent $ into proper measuring equipments and check all tolerances and spaces of the motor.. Go from there Or find a machine shop that has years of knowledge/experience with your specific motor and have them tear down the engine and check everything and go from there... Either way be prepaired to pay and invest $

02-13-2020, 08:27 AM	#3
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	also get the full engine gasket set...this should include the DP gasket iirc, get a seal for good (stupid thick gasket at autozone, think permex? makes it...have used them and they are great!) for the elbow to DP, measure and put some new bearings in it...but like stated above would be good to bring to machine shop that can do it and they should help do it correctly...would recommend someone who works on race engines as a lot of the others tend to mess things up...

02-13-2020, 05:23 PM	#7
mechanicalmoron Zilvia FREAK! Join Date: Jul 2013 Location: tx Posts: 1,078 Trader Rating: (0) Feedback Score: 0 reviews	Does the turbo made bad noises, or turn hard, or have any scoring or fin damage? Not saying cheap out on a turbo and risk your motor eating it, but oil in the intake and being able to wiggle the (smooth and nice feeling, unchipped) compressor wheel a bit is par for the course with any vehicle with a turbo. If you need a head gasket you need a gasket kit or the balls and experience and materials to make and fake the gaskets you need. If you've rebuilt motors you should have some sort of feeling about all these questions you're asking...

02-13-2020, 06:25 PM	#8
S14rebuild BANNED Join Date: May 2019 Location: Florida-FAIL Posts: 2,495 Trader Rating: (8) Feedback Score: 8 reviews	Worryn bout a turbo when the motor has issues.....

02-18-2020, 02:18 PM	#11
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	look at twisted motion for help on lower cost for turbo...tear it down, measure it correctly and put it back together!

02-19-2020, 09:43 AM	#13
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	if you have a good micrometer like https://www.grainger.com/product/2ZT...200219162722:s and know how to use it definitely! I would also suggest a bore guage (think that should be able to measure the crank journals too) so that you can tell if the block has had the bottom end machined as well...if it didn't spin a bearing or the bearings don't look to worn sometimes you can get away with just measuring the bearing and get a same size set...also don't skimp on the replacement of wear parts...they aren't that expensive, also would suggest re-do freeze plugs, and actually remove them, not just push them in...its been recommended to me to use bronze as they don't weld themselves in like the steel ones do