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3 Posts
Hello, just joined, new to MR2 ownership but have had long ago a '78 Corolla rally car and an AE86 ice racer. Also long ago rebuilt my own Formula Ford motor, not particularly expertly.
My son and I are undertaking a rebuild on his 4AGZE ('89 SC street/track day car). This car came to us as a non-start, grassroots modified car. We got some notes and the full Toyota manual but no details on the engine internals. It has a water-to-air intercooler, a larger (JDM Previa van?) supercharger, & 180mm pulley. We deleted the stock ECU with Greddy piggyback and the AFM, and got the car running well on a standalone Microsquirt, but have not done any serious tuning or dyno work. This is his first car and intended to be for fun street/track day use, nothing too crazy or fancy.
Motor is out now while the gearbox is getting new synchros. It was running great, compression was even, only issue was after sitting overnight or longer it blew oil smoke on startup. This would clear after a few blocks, then no substantial smoke while running. So, seems like valve seals. Other than that the DIY oil pan (welded-on extra capacity at the front) was leaking and the welds look dodgy, maybe other leaks too but hard to pinpoint exactly where - no obvious mainseal leaks.
We've removed the oil pan and all looks good and clean inside. Somebody has done some balancing and it has adjustable camwheels, so it's not stock but we don't really know what was done. No particular markings on the cams, crank or rods, they look stock. Pistons are marked "2?0610SC7650" (see photo), not sure if these are OEM. The head will come off next and I guess I'll have to cc the chambers or do some other measurements (deck height?) to see if the compression ratio was changed. Only thing I see so far is some black markings on the cam lobes (see photo); they don't feel rough like gouges or spalling.
So, my questions are:
Cheers!
Cheers
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My son and I are undertaking a rebuild on his 4AGZE ('89 SC street/track day car). This car came to us as a non-start, grassroots modified car. We got some notes and the full Toyota manual but no details on the engine internals. It has a water-to-air intercooler, a larger (JDM Previa van?) supercharger, & 180mm pulley. We deleted the stock ECU with Greddy piggyback and the AFM, and got the car running well on a standalone Microsquirt, but have not done any serious tuning or dyno work. This is his first car and intended to be for fun street/track day use, nothing too crazy or fancy.
Motor is out now while the gearbox is getting new synchros. It was running great, compression was even, only issue was after sitting overnight or longer it blew oil smoke on startup. This would clear after a few blocks, then no substantial smoke while running. So, seems like valve seals. Other than that the DIY oil pan (welded-on extra capacity at the front) was leaking and the welds look dodgy, maybe other leaks too but hard to pinpoint exactly where - no obvious mainseal leaks.
We've removed the oil pan and all looks good and clean inside. Somebody has done some balancing and it has adjustable camwheels, so it's not stock but we don't really know what was done. No particular markings on the cams, crank or rods, they look stock. Pistons are marked "2?0610SC7650" (see photo), not sure if these are OEM. The head will come off next and I guess I'll have to cc the chambers or do some other measurements (deck height?) to see if the compression ratio was changed. Only thing I see so far is some black markings on the cam lobes (see photo); they don't feel rough like gouges or spalling.
So, my questions are:
- Any general do's & don'ts or lessons learned to pass on?
- Any opinions on OEM parts vs. aftermarket (rings, bearings, timing belt)?
- Re-use rod, head, and main cap bolts or get new/aftermarket?
- Head gasket - TRD 0.8mm, OEM, or aftermarket? Any favorites?
- Wise to raise the compression ratio, how much, or just leave alone? (S/C, pump gas)
- Any thoughts about aftermarket valves, valve springs, etc.?
- Any issues going back to the stock oil pan? ... it seems the custom one was done just to increase sump capacity.
Cheers!
Cheers
