koopz

Have done a bit if research and haven't come up with many results so here goes...

Have an early 4 port 13b (pre 79) that has had an awesome Bridgeport job done to it in past but the engine burns oil (weak oil control rings diagnosed) . Would like to rebuild the engine using the early plates and rotor housings but would like to upgrade the rotating assembly to series five (rotors eshaft, balancer, stationary gears.) Is this possible? I have heard of being able to mix and match most all 1984(6)+ 13b parts but have never heard much about mixing the pre 1979 old and the new 1984(6)+

​​​​​​If anyone has any insight into if building a franken motor like this is a possibility please share away!

Jeff20B

iTrader: (13)

What is 1984(6)+? Some kind of messed up phone number that's missing some digits?

The answer is yeah 86+ internals can work in 85- rotor housings. But you can't mix 85 and 86 externals like irons and housings.

rxtasy3

iTrader: (2)

have an 86 e-shaft in mine.

playero

iTrader: (1)

I must have a truly Frankenstein engine...74 irons, gsl-se rotor housings, 92 rotors and 89 e-shaft.....it still runs.....

.::evil inside::.

I've got 1974 rx4 housings, 1990 rotors, 1982 12a irons, 2001 e-shaft, 1990 stat gears, so yeah, no problem.

peejay

I have Series 4 rotors in an early 4 port based engine. It all just bolts together and works. The Internet told me that the 3mm seal and 2mm seal rotor housings are different in shape, but I put them together on dowels and they were identical everywhere.

If your oil rings are gone, you probably have to have your side housings lapped/ground. Pre'78 stuff was not Nitrided and it wore relatively quickly.

You'll probably want to use your existing eccentric shaft as it doesn't have the oil thermopellet thing that can fail. You may want to stick with your existing rotating assembly if you want to use carbon-aluminum apex seals, 3mm carbons are okay but the 2mm carbons have a frightfully short lifespan, by all accounts.