What to look for before buying an SR20DE Autech?

[GoldHawg]

I'm considering the buying the engine in the pics; JDM w/60k miles. Looks exceptionally clean on the outside and is a fair price. Since I won't be putting this in a car and firing it up for probably a year, I'll have no recourse if it doesn't work out well. What besides a compression test should I look for? Obviously compression should be relatively even across the cylinders but what top line # should I be looking for to indicate a good engine? It has the ECM and MAF and wiring harness looks complete, although at the back one connector or something was cut (with a few wires).

Thanks!

[spriso]

Standard stuff.. .pull the valve cover if you can and take a look at the valve train-- make sure that the cams look clean and there is not too much oil sludge-- the cleaner it is the better.

Looks complete, and that is the way you want it. You won't be able to use the beautiful Autech headers, and you will need to have the computer reflashed (with retarded fuel and timing maps) to deal with our lower octane fuel (since this is an Autec version), but they are a hoot-- the Autech powered SR20 Miata we built is a riot to drive!

Michael

[GoldHawg]

Michael
Re the header, do you know if it will not fit in the chassis (major hitting of frame or something) or is it just the steering shaft that is in conflict? I'm wondering if I could use it if I was willing to have the shaft run thru u-joints and do extra work with the shaft. I've heard the Autech header really flows well. Any idea how much performance you lose going to the factory FWD manifold?

[spriso]

The exhaust manifold will hit the frame and the steering column. I brought a brand new Autech manifold back from Japan with me on one of my trips with intentions of putting it on one of my SR powered roadster back in the day-- it was not even close.

I have no idea what HP loss you will have but it will be there. But also remember, that the Autech setup runs a 2 3/8" exhaust system (ie. huge!) from the factory too. Very big, very loud without a huge muffler that you have no hope of putting under a roadster.

I would still pick it up, even the amount of hp that you lose won't be that bad-- they are 200hp from the factory, so even if you lose 10hp it will still be a fun ride!

Michael

[nissantoy]

GoldHawk

take a look at rc mike's 68 sr20 in members rides, toward the end there is
a custom header he had made for his not cheep but very sexy.

nissantoy

[GoldHawg]

Well, the Autech engine & tranny is in the back of my minivan. I'm temporarily in the DC area but will be heading back to Ohio mid-week. I had some trepidation, cuz I was not happy with the compression test. First time thru was totally dry (they drain all the oil prior to shipping from Japan), and 3 of 4 cylinders ~130 psi. The fourth, however, was only at 80! The guy working there said this is not uncommon with their JDM engines, as the long period of no oil can cause the rings to stick. He then squirted oil in all the cylinders, put the plugs back in and cycled the engine and repeated the compression test wet. All of the cylinders were ~ 150 psi, (3 slightly higher, one slightly lower). The 80 psi cylinder was up about 160 on the 2nd wet compression test. Since compression tests should be done on a warm engine (I've heard of 10% or better improvement with an engine at normal operating temperature), this seems like it was probably ok. I called a friend that is more knowledgable about engines and he said the guy was correct that it could all be fine; worst case is I might have to put the engine on a stand and replace the one piston's rings. Hoping that is not the case, but I'll repeat the compression test in a month or so to see if it is still ok. I had previously negotiated the price down to what I thought was a good deal, so I took it anyway. Crossing my fingers that it will be ok.

[Gregs672000]

A leak down will give you a much better eval of the engine condition, and will identify any weaknesses and where... Rings vs valves. Harder to do, especially since you need to have a way of keeping the engine from moving or turning when you put 100lbs of pressure into each cylinder at TDC for the one you are testing. If you are not familiar with how to do this test, I/we can guide you when you're ready.

[GoldHawg]

Pulling off the wiring harness today make it easier to put the engine on a stand, and I have 3 connectors that I'm not sure how come off. Anyone know? Also, how does one specifically apply power to the starter to turn the engine over for another compression test? Hate to admit I've never done a compression test w/o having an engine in a car with a key and battery to turn it over! Any pics/videos to show? Can this be done with a battery charger or do I have to have a battery? Or better yet, can I just use an air impact on the crank pulley to spin the engine over while its on an engine stand?

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[spriso]

Jeff,

I like to use a battery when doing a compression test with a starter-- the battery charger typically does not pull enough amps.

Positive to the Black/Red wire, ground to the block, and touch the black/yellow to the positive lead and it will turn over. Make sure that the trans is in neutral and you have some oil in the engine.

I would not be to fussed with running a compression check on that engine however-- it will be fine.

As for your electrical connectors-- the VVL solenoid needs to have the wire retaining clip removed-- use a very small flat blade screw driver to pull the connector off over the retaining tab. The connector will then slide right off.

The Injector/Knock sensor sub harness plugs are removed by pushing that small retaining tab IN and pulling up on the plug. They can be tight, but it should pull right off. You can see the retaining tab on both the plugs in the images you posted.

Let me know if you get stuck.

Michael

[GoldHawg]

Well, wiring harness is off. But I still managed to crack one piece of the end of the VVL connector to try and get that wire off. Why do manufacturers have all different type releases?
On the good news, which I really don't understand, I redid the compression test w/my own setup and every cylinder was right at 200psi! I don't know if the JDM supplier's tool was off or what, but I don't think I have any problem with the engine.

Finally, I removed all the bolts (I think) that hold the tranny on, but it still is on tight. I'm guessing it must just be stuck on the dowel pins. How do others get this off? Beat on w/a rubber mallet? Pics below

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[spriso]

Remove the starter!

Also, there are some smaller 10mm bolts (14mm head) on the underside of the bell housing, make sure you don't miss those!

Remember that the S15 uses a deep flywheel, so you will have to pull it straight back quite a ways to clear the clutch-- you will see once the trans is off.

Michael

[GoldHawg]

Remove the starter!

Also, there are some smaller 10mm bolts (14mm head) on the underside of the bell housing, make sure you don't miss those!

Remember that the S15 uses a deep flywheel, so you will have to pull it straight back quite a ways to clear the clutch-- you will see once the trans is off.

Michael

Starter is off, just hanging in front by wire. Do you mean these two bolts that appear to go thru the oil pan into the bellhousing (about 6 o'clock)?

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[spriso]

No-- that is just the cover for the torque converter for the automatic cars.

If you have them all out (and the starter is out) then just wiggle the back of the trans and see if it budges!

-m

[GoldHawg]

Thanks. Tranny now off and engine secure. With the much larger flywheel setup It will not go on an engine stand w/o me getting some really long bolts. So I just secured it to cart on castors so I can move it around. I removed all the accessories and the exhaust header I won't be using. But I'm wondering; given the alleged 60k miles on the engine, should I take the setup off anyway to replace the clutch disc? What do you all do w/medium mileage clutches?

[pebbles]

But I'm wondering; given the alleged 60k miles on the engine, should I take the setup off anyway to replace the clutch disc? What do you all do w/medium mileage clutches?

Apply a paint stripe to the PP and flywheel, to maintain balance/alignment at re-installation.
Remove PP and inspect the flywheel and PP for cracks, hotspots and wear/grooves.
I would replace the disc and the T/O brg, if the PP and flywheel look good.
Scuff the pp and flywheel with some 60 grit paper by hand, if they pass inspection, prior to installing the new disc.