ThePass

iTrader: (3)

I've got a spare engine sitting in the garage, and I want to prep it for going into the car now - my engine has been low on compression for a long time, and it is also leaking like a collinder, so I don't think I'm going to wait until it stops producing power to replace it, like I was planning on.This is a totally stock motor, and is intended to stay that way - I'm trying to keep the motor itself as cheap and replaceable as possible, make power via boost alone for now, so not changing any internals or anything.

I was wondering what you guys think are smart things to replace/refresh while it's still sitting on the engine stand.

Engine has ~110k on it, solid compression numbers.
-I'm thinking full seal/gasket/rubber hose replacement of course.
-What about head gasket? If I do this, I need to get new head studs right?
-I am not sure about when the timing belt and water pump were replaced. If I can get that info, I might not do it if they are fresh, otherwise probably a good idea too..

And the only concern I have with the motor is that it has a brownish discoloration in all the areas that pass water. Old owner of the motor said it was like that when he got his car, never had issues but the water was always brown-ish/orange-ish even after flushing it.

-Can I have the motor cleaned out somehow by a machine/engine shop or something before I put it in or does it need to be fully dissasembled for that?

-Ryan

Midtenn

iTrader: (15)

If its been sitting a long time, make sure the oil rings aren't stuck to the pistons. I know a member here got a junkyard motor, perfect compression and leak down. Installed the motor and it smoked like a train under decel. Turns out the oil control rings were stuck in the piston.

I know rotary engine mechanics will put some ATF in the motor to loosen carbon deposits to get the apex seals to move again, but I don't know if that's a viable option on a piston motor. You may want to pull the pan to do it.

ThePass

iTrader: (3)

Thanks for the input. Motor has been out of my friend's car for roughly 5 months, and has sat in my garage since then. If I put a wrench on the crank bolt, it turns smoothly, so I would think it's OK in that regard.

M.Adamovits

When we got our 1999 as a road car, it had coolant exactly as you describe. We took off the the upper rad hose and hose clamped and garden hose flowing at low pressure. Disconnected the lower hose as well and let it flow thru for a while. A couple hours if I recall. After the the coolant always comes out as clean as it goes in.

comradefks

iTrader: (3)

Don't know how much tearing down you plan on doing to the motor but when I did my rebuild last summer I went mostly through everything. If you want to refresh the motor when disassembling it I would do the following. Parts are cheap (enough) and there is some "while you are in there" type of items. I know you track the car regularly and are pushing about 200hp right? So some money up front may be worth it.

- Seals/gaskets - OEM kit is about $200, change out what you want from there.
- Piston Rings - A set is about $50-100
- Rod Bearings - ACL Race bearings are around $100 for a set I believe
- Balance the rotating assembly - $100-150 at a machine shop and it made my motor a lot smoother. Also puts less strain on various parts of the motor.
- Check/Service Oil Pump - Case by case, make sure it's good.
- Water Pump - Pretty cheap part, piece of mind thing for me
- About head studs, I believe they are not torque-to-yield and can be reused. Others could chime in here.
-Don't know if you already have a coolant reroute but it would be a good time to throw that in as well.

That's all I got off the top of my head.

Fireindc

iTrader: (13)

I'm putting a 140k mile 99 motor into my 90. I verified it had good compression and ran great before pulling it, or else i would consider doing a full on rebuild. This is what I've done.

Timing belt/waterpump.
Front/rear main seals
Cam seals
VC gasket
EGR delete
Coolant re-route
Oil pan gasket, oil pan removed to drill/tap
motor mounts
resurfaced flywheel, new throw out and pilot bearings

In addition to that I will soak the cylinders in mystery oil before the first restart of the motor. It last ran.. 4 months ago about. We did this same thing on my brothers sr20 that was sitting for over a year, and it doesn't smoke at the least and makes great power.

I will also flush the coolant passages with a hose like Mike said above. Good idea.

ThePass

iTrader: (3)

Thanks for the input guys.

Just confirmed with the PO that the engine had the water pump and timing belt done very recently.

I intend to replace every seal/gasket in the thing, including head gasket. Still wondering if I need new head studs in that case.

Maybe when the head is off will be the best time to try to clean out the water passages... I'm thinking I can try flushing it with water, but maybe also wire brushes/brakleen or something similar will get the stubborn stuff..

I have a coolant reroute already, which will of course be transferred to the new motor. Lots of other little things I want to do while the motor is out - change to a one-piece NB lower radiator hose, change my turbo drain line to an Aeroquip push-lock instead of SS braided, build a heat shield for the turbo that actually covers everything..

Possibly resurfacing flywheel is a good idea if it looks like it needs it too..

Didn't FM sell a full gasket/seal kit? I can't find it on their website now..

-Ryan

hornetball

iTrader: (4)

If the engine is stock, it uses head bolts. The bolts are not TTY and can be re-used.

The only thing I'd do that hasn't been covered is to get rid of all the little coolant hoses that go everywhere. Delete the air valve, etc. Anyplace that Mazda put a rubber plug on a tube tap to quickly swap the motor between FWD/RWD/Manual/Auto configuration should be pulled and replaced with brass or SS plugs. I'm thinking "cursed water plug," manifold vacuum tap on the rear of the IM, water tap for the throttle body, etc. I've got pictures of those locations in the coolant reroute part of my build thread.

Ellianedwin

Check your engine with a mechanic to make sure it still working better.
If it has low on power output or making some noisy sound, then first repair your engine with replacing part if need before installing it in car. To proper installation, your engine in car you should make sure with each step to go with proper guidance with a mechanic.
For getting some help for swapping your engine, you can check some online page like Engine Basics - Learn, Repair, Rebuild, Install & Troubleshoot Engine Problems. From here I got helpful tips related to swapping.

Soravia

ATF does little to clean engine properly. You best bet is a gallon or so of Carburetor cleaner fluid. Soak the engine part in it and then use hard tooth brush. Things will come off real easy with that.
Pull out the oil pan and replace the gasket. I'm sure there's stuff sitting in there that can use a good sweep.

PCV valve grommet will be hardened and crack easily. Replace it along with the $2 PCV valve. OEM or aftermarket for most Toyota works.