new to the group. hi everyone !! short and sweet -- wife bought an 80 trans am. not in good shape at all, but does have a rebuilt motor and runs great. the p.o. had the engine rebuilt, opted not to spend the money on the turbo and now it is just a 301 with a cam.
the car is quick, yet not fast. what i'm hoping to do is keep the rebuilt engine, but change a few things like the heads, intake, exhaust, etc. to achieve 250 to 300 horses.
not really looking to keep it stock, so a different motor is not out of the question, but i do have a rebuilt to work off of.
what do you guys think ?? is my current engine workable, what would you change, or should i follow the old rule of "no replacement like displacement " ??
You didn't say what was put into the engine when they rebuilt it. It will make a difference as to what kind of hp numbers you can get out of it if they put back the low compression pistons that work with the turbo. I don't know for sure that they used lower compression pistons but that was usually the way it was done. I personally would try and put the turbo system back together again. The 301ci wasn't exactly known to be a great horse power builder even with a turbo on top of it, but I'd do it just to have it the right way.
A good friend of mine in the 80's had a 80' or 81' Turbo Formula with a slushbox. It was very respectable on the street. 1st gear would shred the tires while 2nd. and 3rd. would always catch and make a great chirping sound. It was loaded with most of the options available at the time, including 4 wheel disc brakes. Nice. If I could find one I'd buy it up in a heartbeat, even if I had to get rid of my 88' Formula.
If you don't care about having the correct engine in the car then you should look into either a larger Pontiac engine or go the corporate route. Both will fit.
not sure about the pistons. i know who rebuilt it, mebbe they have some paper work still ( about 7 to 8 years ago ).
i'm just looking for some options, other than a turbo, that will work with what i have on hand. it seems to me that 301 ci should be able to give me 250 workable hp without getting too extravagant. but i don't know of a workable combo. are the heads such that this is the limiting factor ?? seems to me that i read something similar to that effect. mebbe a 350 ci (yeah- i know. so NOT stock) would be a better route for MY purposes. while i do appreciate properly restored cars, i'm not necessarily into factory restoration. this is my wife's weekend warrior with t-tops car that she has always wanted. just want some more oomph to live up to the trans am image :) heck, my full size van gives it a run for it's money.
I remember reading a site that the company or guy did a buildup of a Chev
305 into a firebreather of an engine. I realize its two different type of engines but I ll look it up and post it here. Just to give you an idea of the work that went into it. 305s aren t known to be real screamers back then either but it was certainly a respectable engine after the work
There is not a whole lot you can do with the Pontiac 265/301 cu. in. engines. They are "short deck" blocks so they don't use traditional Pontiac heads or intakes. The 301 uses siamese intake ports which were good for weight reduction and economy but did nothing for performance.
Porting the 301 heads and intake, a better cam and bumping up the compression about all you can do.
Due to the intake design they run out of breath around 4,000 RPM.
First I'd re-tune/fiddle with the advance curve on the HEI to let the cam work better. You didn't mention if it was carbed or had the TB FI system, both have things that can be tuned/tweaked. Exhaust, bigger cats or a good cat back system. The numbers you want are easily attainable for a price tag that won't set your wallet on fire.
I can't really think of any reason to keep the 301, any decent 350 would be so much better, and would be much easier/cheaper to get decent parts for. A T/A is, weight wise, a tank. The 49 cubes of a 350 would be a huge help dragging it around. Just about any GM motor ever made will fit, the hood scoop is the main problem with the swaps. I saw a totally stock looking T/A bout 15 years ago with a Buick 455 in it. The hood scoop was home cast and looked like GM had made it. That thing was great on the street..as good or better than my car.
A friend had a 403 Olds in his 79, like I did, and when it blew up, he put a 454 crate motor, and a turbo 400 in it. It was a pretty simple swap. Ran about .3 second quicker than my intaked, cammed, head ported, etc 403 T/A did, but my car was a much nicer street drive. That thing had amazing off idle throttle response, his car had to be revved pretty high to equal my car's 0-60 or so shots, and I got 3 MPG better than he did. Side by side at the track, with both cars having 3.51 gears, we both had problems launching, but if we both hooked up, my car would barely beat his car to the 1/8 mile, but he would drive around me, and really start to pull away as we came up to the finish line.
I was a dope to sell it, a Vegas car with no rust, all it needed was new paint, carpet, and seat belts. It wouldn't have hurt to rehang the front quarters too.
I think the trans has to be changed, or an adaptor or something might be needed, I don't really know. The motor mounts would have to be changed, and at 25+ years old, it would be a good thing anyway.
The 301... well... sucks. No torque down low, no power up high. I don't even know if you can get headers for 'em.
My $.02 (and I have an 80 TA project car that had a 301) is either a 350 or 400 or 455 Pontiac V8, or make it a Camaro under the hood with a 350 Chevy. The 350 Chevy is easier and cheaper to find, but you need to do more fiddling to get it in. Example -> the Pontiac and Chevy V8 bellhousing bolt pattern are different, so your TH350 won't bolt up to a Chevy without an adapter. (Unless you've got a dual bolt pattern transmission, they do exist, but you probably don't.)
Basically, the problem is the 301 was a "dead end" motor - not a lot of power in stock form, and virtually zero aftermarket support, and not a very strong foundation either - it was a "lightweight" version of the regular Pontiac designed to shave some weight, but at the expense of durability at higher than stock power levels.
heck, for $1600 you can get a 290HP 350 Chevy from Summit. Brand new.
I do have to add that if you go with any other engine, start hunting ebay for the correct shaker, or be prepared to mod yours... each engine used in a second gen TA uses it's own shaker... and they're sometimes different year to year - the styling and the opening changed as well.
You could also consider a set of steep gears if you want to keep the
301... it'll get you moving off the line a lot better at the expense of wrecking what fuel "economy" you're already getting.
I'm holding out for a 455 for mine, but at the rate it's going, there won't be any gas left when I finally get it back together. My dirt track Camaro sucks back all the time and money now...
i my self have another 1980 firebird im working on my own this time the last one i did with a stock 301 i was able to get 425hp at the real wheels all i did was new headers 3 inch flowmasters new fule and oil pump msd box mallory distrubter tayler plug wires and a holly 650 dubble pumper. im planing to put a cam n lifters in mine but the hole upgrade rebuilding it new seals paint n all came to $1600 canadian
425 from a 301 by changing the exhaust, pumps and the ignition?? I m seriously doubting that, sorry. Without changing cams intakes and some other items, you just wont get much HP increases with what you changed. Could be wrong, but doubt it.
Must be, because to add , hmmm what about 275 hp to a stock 301 by adding that stuff. Sheesh if it was that easy, we d all be running mega hp machines for little or no money
I believe and dont totally quote me but the numbers kicked around for a naturally aspirated 301 engine code YN or Xn was about 150 and for the turbo code YL was 210. Different places give small differences in numbers. `So to get an additional 325 hp on a stock engine, lol sure didnt come from a distributor spark plugs and wires and so on.
Don't forget, each decal on the window is worth at least 75hp. Just ask the Honda guys. ;)
The basic bolt ons may have gotten him from 210 up to 240, but by the time you factor in the racing stripes, JEGS stickers, etc, you're up to at least 500hp.
lol, yep my point exactly. You know you get to a certain point and then you fight for every inch of power you can find and then someone comes along and gets an extra 275 hp for basically nothing. I must be doing something wrong lol
When I ran my aluminum head, solid flat tappet cam 455 the dyno showed 418 at the rear wheels, ET calculator shows around 430 hp. If I can get the same power out of a 301 for a lot less money I'm giving my 455 away and building a 301.
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