I'm looking for some FIRSTHAND experience, meaning someone whos actually done this or is close with someone who has done this... Putting GSL-SE rotors into a S4 block.

EXACT QUOTE FROM A OLD RACING BEAT CATALOG:

"We do not recommend swapping rotors from 1986 and later engines with 1985 and earlier 13B engines. There are small, but significant diffrences in the shapes of these two generations of rotors. You run the very serious risk of having the rotor flanks crashing against the rotor housings at higher rpm's."

I've heard of it being done but never talked directly with someone who's actually done so.

The key word that intrigues me is "recommend". That kinda says it'll work but at the same time says it won't... Anyone...?

 

I know that importboi22 TRIED to do it and the motor continualy ate its stat gears untill he gave up trying. Wether or not it was due to the shape of the rotors, im not sure

 

ya that was true... but it was also due to a few other things....
1. thermo pallet broke
2. the eshaft end play was set wrong via a incorrect spacer size used by the builder.....

 

my question would be why?

 

gslse rotors have 3mm apex seals stock, you wouldnt have to get the milled out.

i dbout thats true. a rotor is a rotor imo. i sold a set of se rotors to a guy in florida using all kinda of different stuff to make a drag engine. dont know what ever happen to it, but maybe hes around on hte forum still?

 

Same reason piston guys run 12.0:1 Higher compression ratio...

Same reason draggers use heavy flywheels...

My question is why not...?

 

A drag motor may be mated to a heavy flywheel but they are definetly not built with heavy pistons, rods, cranks, and valve train parts. And if you want the most compression you'll need an S5 rotor. I'm with Tim. Why?

 

Am I wrong in saying... Wouldn't the rotors be part of the same rotational mass that spins the flywheel...?

I do realize they are not spinning in ONE circular motion like the flywheel is doing... but at the same time I would think the heavier the rotors weigh the more enertia/force it would create.

I'm getting alot of negative feedback from the people I talk to about how the compression is tooo high for a T motor... S5's are even higher. (85=9.4:1)(S5=9.7:1)

I'd rather hear ways on how to make this set-up work, (ex:ways to avoid detonation) or ways why it won't work.

Just like the earlier replies, I didn't start this post to explain to others why I might go this route... because I'm still not 100% sure about it myself. I do know that I do have SE rotors and seals waiting to be used somewhere in one of the motors I put together.

So again my question is why not..?

 

I have done it twice and I would not recommend it. Both motors ran ok but for some reason one chamber had low compression. I have NO idea why. The only thing I could think of is the side housings have the grooves left by the .7mm side seal and it tracks different then the 1mm side seals, however that should effect all chambers but not just one. Both motors did exact same thing and I am careful when building motors. It will run ok but will have just that miss at idle. Both motors were stock 6 port with FI. The first one was GSl-SE with 86 housings, it detonated and let go, second one was 89 motor and FI, it was a slap together so I can sell car motor. It would be interesting to find out why it did what it did.

 

OH the first motor was taken apart. Classic broken end piece, no sign of rotor touching rotor housing.

 

All three of my plates have been lapped by Racing Beat.

How many miles did you get before breaking it apart...?

Classic broken end piece meaning the small triangular piece of the apex...? How was it broken.. small cracked bits or literally broken...?

Ohhhhh yea... and ALL my seals are BRAND NEW and rotorhousings have NO wear whatsoever.

So if it doesn't work right, when I take it apart I SHOULD or at least hope to be able to tell why.

 

2000mi.
pointed edge snapped off.
used stuff.
I don't think the broken seals are the result of mix matching rotors. Take it apart and see, may be you can tell me the answer of this mystery.

 

Well, I haven't put it together yet. Probally by the end of this week.


I bought a set of used 3mm GSL-SE seals that were used on SE rotors in a 2nd gen block (internet deal)... and the tips on the slanted part where the two pieces of the apex seal meet have very small pieces missing/cracks. Needless to say I'm buying new seals... but this is worring me.

I MIGHT just buy new seals for my S5T rotors and play it safe. My cars been down toooo long to go experimenting.

 

Small missing chips are sign of hi miles apex seals. It looks like a chipped tooth right?