Re-Mounting an SC14 on Exaust side of a 7AGZE

[PRIMRK]

Building up a 7AGZE 20v for my AE86 and am going to mock up some mounting and plumbing stuff on a half cut.

The main thought is if i mount the intake and SC on the exaust side of the engine then run through the front mount cooler then to plenum and quads, this seems to be the shortest and neatest way to do things

BUT! By having the SC on exaust side it will be subject to heat from the exaust.

Now the intake is cold air with the headlight removed and a vent in its place, so nice and cold, then through the charger where it will be compressed and gain some degree of heat, then through the cooler that will disapate it.

Will the heat form the exaust effect the SC? Not so much as intake temps as the cooler should take care of that but more on the running of the SC?

[oldcorollas]

it will affect it less if you have a double layered barrier of that ACL heat shield stuff, but you'd always wonder, with heat soak, if it was a good idea

you can get IC's that have inlet and outlet on the same sides...

[PRIMRK]

Yeh, i will be heat shielding, wrap the exaust man and some of that ACL shield around the SC i figure that would keep it fairly cool, even so im waiting on a 7A block and SC14 till i can even see if it will fit down there...

Ive seen the coolers that are in and out on the same side its just that mounding the sc on the left as well as running quads and the plumbing is going to be a bit tight, again i havent mocked anything up yet.

Either way i need to fab the stuff to mount the SC also if its on the exaust side and i decide to turbo it (doubtfull but maybe) then the plumbing work wont have to be changed too much.

[PRIMRK]

So anyone know if heat effects SC's in a bad way?

[TERRA Operative]

Excessive heat will melt the coating on the lobes of the charger, however, the main cause of concern would be the clearances closing up between the lobes and casing from excessive heat. Also the bearings may be adversely affected too.

Having said that, the supercharger is designed to work in a pretty tight engine bay for a few hundred thousand kms, so if you go a bit overboard with decent heat shielding (The stuff used on the turbo Falcons is apparently really good) and some header wrap, then I don't see why it couldn't work.
SC14 chargers are only a few hundred dollars a pop, so if you get one or two years out of it before it dies, it's not too bad. Just keep the oil fresh and the blower as cool as possible.

[PRIMRK]

it will also be running a 70mm pully so it will be running about 14psi...can you get these things rebuilt?

[TERRA Operative]

14psi is at the absolute limit. the maximum long term boost ratio is 1.8, which equals about 12psi, the maximum short term boost ratio is 2.0, which equals 14.7 psi.

The superchargers can be rebuilt to a certain extent. You can replace the rear bearings and seals, but if the lobes become damaged or the front bearings fail, it's time for a new supercharger.
(You can't get front bearings unless you want to order 1500 of each type, and the re application of the coating has never been tested).

Your blower can't be expected to last too long at 14psi due to the heat rise (I'm not sure how long it will last though). Maybe if you installed a water sprayer pre-charger you could keep the temps down.

[foamy]

I don't think you can? I know a few of the mr2 guys looked into getting the rotors re-coated but didn't get anywhere with it.

[PRIMRK]

so if i see a SC14 up ill have to grab it and have a few in stock...

[TERRA Operative]

Yea.

Like I said, the rear bearings and seals are all that you can rebuild. Anything else and it's new charger time.
I'll be putting an SC14 (just rebuilt it as far as I could) on my 4AGZE in the next few weeks, but I'll be using a 103mm pulley bros pulley on mine.

[PRIMRK]

hmmm...maybe i will just go turbo...

[sprinter86]

7agte 20v is what you want

im currently in the final stages of one atm

[nick.parker]

14psi is at the absolute limit. the maximum long term boost ratio is 1.8, which equals about 12psi, the maximum short term boost ratio is 2.0, which equals 14.7 psi

True and good advice, however you can push them harder...
With my AW11 I push 17.6psi from my SC14'd GZE. (172mm on the crank and 120mm pulley on the SC). My car is only road driven, and revs are kept below 6500 generally. The SC has been fine for the last 4 years and low end torque is pretty satisfying from such a small engine! Before that I had another SC14 on for two years. It didn't fail either I just swapped it off as part of an inlet.outlet porting experiment...

Nick.

[TERRA Operative]

You're just under the bearing speed limit of 10,000RPM if you stay under 6500RPM.
You'll have to watch the supercharger temps as extended boost will overheat the blower.

[nick.parker]

Yep Terra, I factor the 10k limit into my "pizza box" calculations. Also as a general thought, the whole 7A bottom end thing is appealing to me with my current setup - with the same pulleys I could expect roughly 13psi-ish, and I'd be operating in a more efficient part of the SC performance map. I'd expect (things done right) to achieve a decent torque gains, and more power too. 200rwhp with a 7A bottom end should be possible.
Nick.