305ciRX7

This is my first post on this board, this is also my first rx7 so if i sound like a tard dont bash me to hard please.

I recently bought a RX7 that had the v8 conversion about 95% done. All i have left is wiring cooling fuel and a shifter.

Here is the setup

89RX7 Base 4lug
Freshly rebuilt 305 (.30 over heavier cam edelbrock performer stuff)
rebuilt 350turbo trans

So i have a couple questions.

First which shifter should i go with that will fit in their nicely. I have a B&M megashifter with a 4.5inch stick.

How should i run my fuel?

Dont know what to do about tranny cooling.

I have a 4 core radiator, but what about fans.

Hardest one is which headers to get for this 305.

Any and all advice is more than appreciated. The guy that had it before me gave up when he got to the wiring, he cut the hell out of the harness and then gave up so i orderd a new engine and body harness and just going to start over.

Sizzlenut

As for the wiring, you'll need a wiring diagram from the car that the ecu came out of. Constant 12V, switched12V, GND, fuel pump relay, cooling fan relay misc. controls. Taurus fan (1993? body style) works very well, lots of CFMs and the shroud can be attatched to any rad pretty easily.

Tranny cooling??? I run a 6 spd.
Headers??? 305 specific

Fuel: Walbro 225. I run stock rx7 lines with a walbro but will be upgrading the lines ASAP.

Warning: THis is a drunk post. Hope I didn't **** up.

305ciRX7

thanks for the info..

Yeah i have a 350turbo auto trans.. So i suppose i will need a oil cooler for it, i found a descent one by fluidyne that i suppose i will pick.

If anyone knows anything abut a points ignition i need some help with it. Im getting juice from the coil, and the cap itself is getting juice but after that im not getting any fire to any of the cylinders.

Im pretty descent under the hood of a late model turbo car (I have a 3000gt VR4) but stick a old school small block chevy infront of me and im retarded lol

LT-x7

I thought 305 headers were the same as every other SBC headers?
If that is indeed the case you have several choices, I run the Grannys speed shop headers and love them. Expensive but worth it.

There are tons of universal tranny coolers that will work, just pick up a summit. The hard part for me was making the lines, I ended up with a combination of 3/8" aluminum fuel line and 6an steel braid because of lack of room in the tunnel.

Check out the final drive with that TH350 with the Mazda 4.10's and short tires. Most people ditch the TH350 for something with overdrive. I run 25.7" tall tires and can't finish the 1/4 without hitting 6000rpm in 3rd. If your gonna keep that Th350 I recommend the tallest tire possible.

Nihilanthic

BTW, if you havent heard this before - 305s have smallish bores and the heads they have combined with the small bore = shitty breathing.

Unless youre a headwork pro, the only way to make any real power with a 305 is forced induction.

305ciRX7

yeah i know that much about 305's like i said the car came with a 305 sittin in it.. but if i get bored with it i have a low mileage LT1

Nihilanthic

I dont think you can bore the block to 350 cid... the other thing is it doesnt have a 350 crank in it, its got a longer stroke. So youd need new crank/rods/pistons, and thats assuming you have the cyl wall thickness to safely bore like that.

Unless you really know your **** with headwork (and Ive seen 400 hp from 305s with some GOOD headwork) Id just say boost it.

Its how you make power with a 2.3T anyway well, unless you port the hell out of it or get a better head anyway. Pressure can defeat shitty flow, to a point, is all Im saying.

305ciRX7

well i do have a extra set of stock 9b turbos off of my 3000gt i could slap on it.. they only make like 12psi but it would still be fun and they would spool up in record time.

digitalsolo

iTrader: (2)

Turbos don't make "x" boost, they make "x" flow efficiently. Boost is a factor of multiple variables.

And Nihil is right, a 305 can't go to 350, the bore centers are smaller, you'd have more then one piston in each cylinder if you did.

305 is still enough motor to have some fun with in an RX7.

Nihilanthic

You can flow high pressure efficiently with the right turbo to make up for bad airflow through the heads...

Ive also seen that serious port and chamber work can make a 305 pretty decent NA (400 hp), but cheap and easy would be just shoving air down the bad ports at a high pressure. Two holset HX35s, a IC, and the ability to supply enough fuel could do you well, but youd need to know how to do the piping or get someone to do it for you. And, well, a airbox around a carb or a tuneable EFI.

But yeah, RX7s are light. You wont be out taking out corvettes with a stock 305 but you can still have a blast.

305ciRX7

great guys thanks for all the info.. At this point im actually trying to fire this motor up and make sure it isnt junk. Im having issues though.. I bought a really nice HEI distributor and i wired it up temporarily just to fire the motor up.

Basically and correct me if im wrong but really all you need to do on a HEI distributor is Run a 12V power source into it and the distributor and it grounds itself. Well just to try and turn to motor over i ran that wire straight to the positive batt terminal and tried to turn it over.

Coil is getting juice the juice is going into the cap but nothing is coming out for any of the cylinders.. Anyone know the proper way to wire a HEI distributor up in this thing.

Nihilanthic

http://www.torquecentral.com/forumdisplay.php?f=11 <- v8 swap forum.

Also, virtually any enthusiast forum where theyve worked with chevy v8s would be able to help you.

Orr89rocz

yes, any small block chevy header will work for a 305.
i would go no larger than 1 5/8 inch primary tubes. for smaller v8's those will be big enough.

if your motor is carbed now.. then you just need to worry about basic wiring... you can get painless wiring harnesses with 12-16 circuit connections just to wire up your basic stuff.

depends on the carb tho.. the think Q-jets are partially electronically controlled, i'm not sure.

but 305's can make plenty of power. small bore and 350 stroke means it has limited potential n/a but with forced induction they can run well. but n/a they have hope too. theres a guy at my track running a carbed 305 and doing 12.7's with a stick in his 80's camaro. thats a 3400 lb car. another guy was doin consistant 13.0-13.1's at 103mph with his 305 carbed setup.

and the biggest you can stroke/bore them is to about 335 cubic inches.

th350 is an nice trans but i would recommend something overdrive like the 700r4. if your FC has 4.11 rear gears, then that will be way OVERKILL for most motors. alot of race V8 guys run 3.73-4.11's and those motors turn up over 6000rpms and run 11 second 1/4s or faster. depends on what cam and other work is done to that 305, my guess is that it runs out of breath at 5000rpms or maybe 5500. 4.11;s is just too much gear. i would look at something alot smaller. 3.4x if possible

LT-x7

3.9 is the tallest gear possible if you keep the Mazda rear end. Overdrive tranny and/or taller tires is the only option.

Orr89rocz

you probly could look into rear end swap... manual trans or overdrive trans would be nice, or 27-28inch tires would lower that rear end ratio nicely. but 28 inchs is a big tire