Oil jets to cool the pistons?

[jaybee]

So, does anyone know if these engines have oil jets to cool the pistons? I looked at the cutaway diagrams dieseldavo has in his album and don't see any.

[mazdadieselsrule]

They do not. They do have steel expansion rings cast inside to help the piston heat up better and quiet the clatter sooner. "Quiet" pistons and gears as Mazda so put it in their 1983 brochure. ;D

[jaybee]

Thanks for the info. I was hoping they did have the jets. I am getting ready to try a small turbo on mine, and would like the piston cooling that provides.

I guess my strategy now will be to install a pyrometer first, and get a good idea of what the stock max EGT is. Then, after installing the turbo I will make sure to keep the EGT's below that number. I am shooting for about 6-8psi of boost, and figure I'll be able to get more power with even lower EGT's - hence less engine strain. I'm also hoping to shift the power curve down some, and reduce the engine speed since I have such a tall overdrive.

Oh, and I have a spare good engine sitting in my garage just in case this experiment goes horribly wrong!

Jason

[DieselDavo]

The Diesel Mazda Car and Ford Escort did but they both had bigger problems. (Skimpy Cranks, heads and rubber band cam timing.

The Nissan/Datsun trucks 2.2 and 2.5 both have them but they really are fair weather trucks. My brother has one of each and starting at even 0 deg. C is a challenge.

Mazda has an oil cooler and as long as you keep the truck out of 5th gear under 50 mph plenty of oil will be flying off the rods to keep the piston cool.

[Mazdadieselsrule]

I had a 1981 Datsun 720D truck with the SD22 engine. It revved higher than the Mazda and had better pep,mainly because it was a lighter/chintzier truck. The SD22 also had that sucky 3 main bearing crank that everyone else abandoned 20 years earlier in favor of 5 main bearings as was the SD25. Mazda was/is still a better truck if you put all the Jap offerings and also the Ranger, S-10 diesels from that era together for comparasin and reliability. Rust is another story. John.