I have just pulled apart a pinaple racing semi pp block that came in a 1980 sa old race car and want help identifying what is what cause i think its kind of a Frankensteined motor it's got 4 port turbo block with the knock sensor bung above the spark plugs but I'm not sure how to tell the difference between s5 t2 or rew




also might need to have the irons laped and re nitrite there is definitely some deeper scratched they may cause issues.
The other thing i dont understand is the rotors car was originally built to be n/a so I think the rotations assy is using na rotors for higher compression but I'm not sure wich ones they are they have milled compression pockets but the markings on the bearing side don't match s5 or fd rotors


Markings look like an S or 8 and then 1 and 2
also the rotor with the #2 has three dots that the #1 is missing that

#2 with the dots

#1
also here's the machined pockets maybe there rx8 rotors but I honestly have no clue also motor clearly went cause of coolant seals so one rotor has pretty stuck side seals I'm going to have to soak to get put


any info is greatly appreciated going to rebuild and hopefully throw some boost at it when it's back in the car also here's an old setup photo when it was running in the car

also merry cristmas

 

Those appear to be Turbo II side and rotor housings.

The rotors appear to be FC N/A rotors but it's hard to tell. Weigh them if you can, there is a large difference in weight between S4 and S5/FD. They are definitely not RX-8 rotors.

 

the irons can be identified by a casting letter,
S4 T2 is G,G,G, or the US center iron is a Z, i think
S5 T2 are D, D, D
FD is N3A1

the rotor housings are probably S5 T2, knock sensor, no diffuser in the exhaust port.
FD housings are really similar, the exhaust studs are longer, basically

rotors are S5 or newer, they have machined combustion recesses, of which you have the 9.7:1 NA rotor and the 9.0 turbo rotors

pretty neat setup!

 

Looking at the intake ports they can't be FD. The ports are parallel with the ground, not angled like the FD ports.

 

thanks im very exited to get it running not anytime soon though. Think she'll be able to handle some boost then even with the na rotors like 5-10 psi or should I look into a t2 or rew rotating assembly

 

Why did you have to take it apart? The answer to your question is related to that.

 

if you had it apart, turbo rotors would be the way to go. put the right (big) turbo on it, and its going to make a lot of power

 

I'm not sure car had been sitting for a minute but the was some coolant in the rear housing so I think coolant seals went or there was stuck seals but I'm assuming that was from sitting all the seals were in one piece broke a few side seals on the way out but apex seals are still good and closer to the new spec then min

 

do I need a new eshaft and counter weights if I get turbo rotors? Kinda on a budget and its going in a first gen so big big power is not the goal but it would be nice maybe 300-400 if I can. Also just gonna rock it na for a bit I think so I can drive it and try and aquire turbo parts and a ecu on the cheep(ish) side

 

Nonturbo and turbo rotors are the same weight for a given series. S4 turbo and nonturbo are the same weight and use the same counterweights, S5 turbo and nonturbo and FD are all the same weight and can use the same counterweights. So you just need to identify which counterweights you have, and go from there. Mazdatrix has a good FAQ page for identifying counterweights based on some easily measured dimensions.

If you had a coolant leak, that may have come from a leak where the peripheral port was bored through, or it may have been from a cracked coolant land, a common fault with the FC/FD side housings. Mazdatrix, again, has a good FAQ page for identifying failed coolant seal lands.

High overlap engines really favor having free flowing exhaust systems, meaning big turbo hotsides, and the kinds of turbos you can find for that really come alive at higher boost pressures than you'd need for only 300-400hp. Depending on your setup, you may be near or over 300hp naturally aspirated.

 

+1. there is a chicken and egg thing, big port wants big turbo, big turbo is efficient at big boost which = big power

 

There is some bad step wear on the rear ironn that I'll probably have to replace but no broken coolant passages or bad corrosion. What kinda turbo would you recomend then I really don't want huge hp cause it's expensive and it'll probably break the rest of the car

 

How bad is the step wear? If it doesn't have something that can catch your fingernail in the oil seal track area, it'll be fine.

OTOH I don't see an air filter on that, which is very bad news.

 

there was an air filter theirs more pictures of the old build and that's the only one where it's not on. Front iron has acceptable step were barly catchs your nail but the rear has probably 2 or 3 times the limit. Is that something that lapping and renitriding could take out or i was just going to buy a new iron
wear is not in the oil track also it close to the spark plugs in the usual area

 

I wouldn''t worry about that at all. That's normal and pretty insignificant.

I don't think anybody grinds and renitrides at the moment, and you really can't do that with FC parts anyway because it makes coolant seal land cracking more likely.

 

they look pretty bad was gonna hit it with a scotch bright pad and see if if they will clean up a bit its very long and the rust worries me.
Found this company that'll apparently do it but never heard of them
https://chipsmotorsports.com/engine-...iding-lapping/

 

Chips is currently not accepting new work, to the best of my knowledge. He's a one man operation and had a pretty bad injury a little while ago.

That doesn't look too bad, aside from the rust. The camera is probably making it look worse. That said, I've never seen machining marks like that and I wonder if those haven't already been ground once before on a surface grinder.

 

I think it has been machined before cause I can't see the lines from the original mazda machining like on other irons. should I try and wet sand it down just a bit with a really fine grit or is that bad for it it also the picture does make it worse a bit is there anything else I can do to kinda restore it as well