Ah, back to the slush turd bashing now are we? lol Come on, my memory isn't THAT bad! We all know who this 'other' guy is now. Opinion, sure. Everything we type out is our opinion, which is why those who had bad experiences with something will not like it, while others who had great experiences with it will like it. I say it's all a matter of preference, and won't bash one over the other. I've had TH400 transmissions clunk out where the ST300 held up, but I'm not bashing the TH400's because of it. I've broken a Buick 8.2 rear end with a factory ST300, but I know for a fact that the Buick 8.2 rear ends are good units. Your experience with the ST300 is with a gutless bonerless stock 300 2v, so there's little wonder you have negative memories. Might as well have had a v6 in front of it. My 350-2 pulled out of the hole better than my 350-4 with the ST300, not to mention the 455's I had in front of them, so needless to say they respond well to low-mid range torque. I've tried to explain this several times before, but until and unless you have experienced for yourself, you're simply not going to believe it. I will reiterate it one more time for those who don't know: hydraulic torque multiplication and gearing is why it puts more muscle to the tires, but if you don't have much muscle to begin with, you're not going to be impressed. If one is interested in 1/4 mile performance, more gears are better, although there are some who use the ST300 in 1/4 mile runs who say they lose a little on their time, but gain on their top end MPH. So it's not completely worthless at the track. Imagine it on the street where seldom are there people going down the road at speeds less than 20 MPH, where you'll spend 99% of your driving time, and you'll begin to see the advantages. I would be more inclined to pull out a TH350 and replace it with an ST300, than the other way around. But THAT---is my opinion. My recollection of past events are pretty sound, and I have nothing to gain by embellishing or outright lying. Luv ya bro! To some other responses: a clunk when downshifting is probably an ST300 in need of its lower band adjusted (see owners manual or online documentation) that is too loose from wear and needs tightening up to remove the slack between the detent piston positions. Buick called the 2 speed automatic the Super Turbine (ST) 300, while Olds called it the Jetaway and Pontiac simply '2 speed auto'---they're the exact same transmission, with Buick and Olds the only 2 using the switch pitch variant. The 1968 ST300 didn't have the switch pitch, and are the ones I owned in two '68 Buick models, a Skylark and a Lesabre. As for rebuild advice, keep the 2 barrel intake, use a larger 2 barrel carb, and use a cam designed for increasing low-mid range torque between 1500-4000 RPM and it'll improve the vehicle's performance using factory gearing and the ST300.
You still can't beat gear multiplication. And the fact GM dropped the 300 after about 5 years and the 350 was in production for about 20 years. GM must not have agreed with the 300
I'll throw my two cents in here on this one as I've been in the exact same spot. I had the 300 with the 2 barrel rochester in it and it was a bit slow with the st300 in it - fun enough. It gave out a couple weeks after I got it back on the road. I lost first gear-I believe the band was adjusted as far as it would go then wore out. It was difficult to find a replacement that I trusted and wasn't going to put the money into a rebuild for a 2 speed (although switch pitch helps). I did the swap to the 2004r and loved it (cost me at most 750 bucks). It was noticeably quicker even having the 2.78 gears. Great fuel mileage but it was way too low in rpms on the highway. The most difficult part was attaching the linkage to the 2bbl carb. I had to fashion up my own brackets and clips. Eventually I found a higher compression 340-4 and put that in and loved that too but fuel mileage was definitely lower. Still fun with the 2.78 gears. Recently put a brand new carb on it and posi rear gears of 3.36. Now it's finally all matched up and love it! It was quick enough for me I may freshen up the 300 at some point and put it back in for awhile if I ever mess with the 340 again.
Not disagreeing, but it depends on the combination and what one intends on using it for. Saying this or that is 'best' for this or that is subjective, and depends on many factors such as engine componentry, power output (but more importantly, where the power is produced), gearing, driving habits, and the vehicle's intended usage. A light car with tall gearing with an engine that produces good low-mid RPM torque is a nice combination. Add in even more power than what it came with from the factory, and it just gets better. GM dropped it along with the powerglide (Chevy) because Buick and Chevy were working together on making a transmission that was more universal with similar components for interchangeability. This was a popular theme GM did starting in the early 70's, with the 8.5 rear, transmissions, and suspension--among many other things. Then started doing it with engines (putting Olds engines in Buicks, Chevy engines in this or that, etc. etc.), along with a common engine color for all makes (blue). The "Corporate" mindset was firmly established by about 1977 or so (even sooner when considering other elements that were implemented) at GM. They also knew the compression was dropping in 1971, and so engines wouldn't be producing the power they used to, and needed an extra gear to help them out. This idea was expanded even further in the mid 80's when the 4 speed automatic was introduced...and so on. If you expect a car to perform similarly with different components, then it's like telling a fish to climb a tree and then calling it useless when it can't. Taking something out of its element and expecting it to perform equally well is not being realistic. As with the people who know the ST300, they can even perform at the track (where the transmission is at its weakest). If it can do this, you can bet your ass it'll shine on the street. My personal testimony isn't what anyone might consider 'proof' (although it's proof enough for me), since there isn't any hard documentation regarding these past events. What we DO have is other people reaffirming my claims with actual drag strip results, as well as circle track racing. Push some torque through a ST300 and it'll take off just fine, and this is it's weak spot. Everywhere else and it outshines the 3 speeds in performance. If you're already moving, the single advantage the 3 speeds had (a lower 1st gear for dead stop take off) is gone, which constitutes the vast majority of where you're going to be when driving on the street. All you guys see is drag strip this and 1/4 mile that. There's more to a car than taking off from a dead stop. If all you're interested in is driving your car 1/4 mile at a time, then by all means get a TH350 or whatever. You will not outperform a ST300 on the street, however. Let's break it down a little further: At a dead stop, the ST300 keeps the torque converter's hydraulic torque multiplication longer than any 3 speed tranny. While this may not trump mechanical multiplication, it helps to offset the tall low gear the ST300 has, so it doesn't take off nearly as bad as you think when you have torque. As the car moves and gains speed, the hydraulic multiplication eventually diminishes and you're left with mechanical multiplication, which by this time is when a 3 speed would be shifting into 2nd gear. Well guess what---the ST300 beats out the 3 speed tranny again here too, because low gear on it has better mechanical multiplication than 2nd gear on any 3 speed tranny. Shift into high gear on the ST300 and 3rd on a 3 speed, and they're both 1:1, so equal, but wait, no they're not--the ST300 has less parasitic loss so more power is STILL being put to the wheels. The main reason people don't dig the 2 speed is because it feels 'weird' to only have 2 gears, and it's not popular with drag racing enthusiasts because of the reduced hole shot time, even though they all know it'll give them better top end MPH at the end of the track. Use whatever you want, but disregarding the ST300 as a worthless or junk transmission is just plain ignorant. No disrespect intended to anyone by this statement. "Ignorant" means 'lack of knowledge' and reflects most people's (nay-sayers) misunderstandings about something. Preference is another thing altogether. Peace
Do a google search. There's a couple places that sells everything you need for a ST300 rebuild, including the low band. They're dirt cheap to rebuild, and the stock parts are pretty durable (holds up to big block torque). Use a 3 series gear with the ST300 and it'll shock you. EDIT: I lost 1st gear on my Skylark's ST300 too, and before that I had never owned one before. I noticed it was revving up a bit just before downshifting into 1st from 2nd, like there was a bit of a pause in the low band gripping. It would 'clunk' or make a sound too before engaging. I got outside one morning to drive it and noticed there was no 1st gear. It had reverse, but nothing in "D" or "L", just like it was left in neutral. I took the oil pan off and saw the spacer in the pan. At the time I didn't know wth it was, so figured the transmission needed a rebuild. Hindsight is always 20/20, and learned later when rebuilding it that the 'chunk of metal' I saw in the pan was the spacer that connected the low band detent piston to the low band itself. The piston expanded when 1st was engaged, which put pressure against the band and caused it to contract around the planetary gear housing that controlled the forward motion (high/low). Pretty simple. Contract the band to engage the planetary gearing for low gear, release for high gear. Reverse has its own set of clutches. Anyway, that's been my experience with a 'clunky' or misbehaving low gear on a ST300. The adjustment consists of a threaded rod (a type of 'bolt') that adjusts how far in the band sits when disengaged, with a nut on it to keep it where you set it. Adjust it too tight, and low band will be engaged (even in neutral); too loose and the hesitation/clunking sound. Even this isn't complicated: tighten the adjustment against the planetary housing until it feels snug (I think it was 18 inch pounds? Can't remember this part, though it doesn't have to be perfect) to make sure the band is aligned properly, then back it out a couple of turns, and tighten up the nut. Boom, done. Readjust every 30,000-60,000 miles.
I could pick apart the previous post sentence by sentence but not going to take the bait on which trans is better than the other. I just want to say that it is ignorant to recommend a st300 behind a sbb 300 2bbl, borderline dangerous pulling out into traffic. It was a really bad idea from the factory, and an even worse idea to recommend staying with that trans behind a sbb 300 in a heavy convertible. That's all I have to say on the subject in this sbb 300 engine rebuild thread! :shock: Derek
We all know you hate the ST300 Derek, it's ok. You have a right to your own opinion. I'm not necessarily recommending anything, just giving some information on the transmission that others may not be aware of. I also stated the transmission works best with some torque, which the stock 300-2 isn't exactly abundant in, which is why I did recommend beefing it up some with a larger 2 barrel carb to keep powerband down low, with a cam that improves low-mid range torque. It still won't be a big block, of course, but will improve performance if he doesn't want to change anything out or do any conversions. Pulling out in front of fast moving cars is dangerous no matter what you drive, since if you have to floor the car and burn rubber just to keep from being hit, you're not a very safe driver in the first place. lol Peace
Staying with the theme of the thread, you can skip a step and do a 300 stroker build and make it a sbb 350 that looks like the factory original sbb 300. Source a cheap '74 or newer sbb 350 for its crank and rods, have your block bored .050" over, have the crank's mains ground down to fit the 300 block and get the customizable AutoTec pistons with the right compression distance to work with the sbb 350 rods and you now have a sbb 350 that looks like a factory sbb 300. Using the AutoTec pistons you can get away with skipping certain machining operations and be able to maintain your valve train geometry while being able to get the pistons at zero deck. 300 heads are the same as 340 heads so you don't have to worry about the 300 heads feeding the extra cubes, but porting would still be a good idea. Better yet would be getting the TA Rover heads max ported with the biggest valves that TA installs in them(2.02" in. 1.60" ex.). That is if there is the extra $$ in the budget for the extra go fast fun parts. With factory heads though and the extra cubes the engine will make gobs of low end torque to get your car moving quite well. Roller cams are available for the sbb 300 as well to further enhance the performance if you like I like the idea of not having to break in a flat tappet cam that can fail even if everything is done right. Good choice on transmissions by the way, no matter how cheap rebuilding the original trans is the 200 was a great choice. Now that the 200R4 is in your car you'll probably never want to go back to the factory installed one unless someone puts a gun to your head. :shock: Derek
You'd never want to use the ST300 with a 4 cylinder engine or a Briggs and Stratton either, for reasons explained previously. With this in mind, the more gears you have, the better a lower powered engine will perform, and with a numerically higher gearing, permits improved take-off as well as great cruising RPMs. The spirit of the thread is preserved, with only a minor tangent addressed from previously communicated inquiries/comments pertaining to transmission choice/options. Long live the small blocks!
Roger, Gary's advice on adjusting the band is certainly worth a shot before switching out the transmission. Additionally, it might be worth putting a thousand miles on the car or so before tearing off the heads for a rebuild. If the engine's been sitting, the rings just might be a little sticky. If it's been a steady driver, then, well... Good luck either way!
I had the same issue on a harsh downshift with the st300 and it turned out to be the vacuum line leading to the transmission. Repaired that leak and everything is fine now. My original 300-2v and st-300 works great as a cruiser with some adjustments, new thrust plate oil pump and gears, cleaned the pickup screen under the pan, rebuilt the 2bbl carb and installed lectric limited points conversion kit and the dual exhaust sounds good. Just a cruiser and not into the drag racing, nothing wrong with that, I'm just not into it anymore. Most of my traffic issues are with people slowing down trying to get a better look at the car. Not to get off subject but these cars are only original once and the hobby needs to be preserved as much as possible.
Nice to see others posting that believe there's more to a car than how fast it can go at the drag strip. I'm a firm believer that Buick knew what they were doing when they built these cars, taking more into consideration than simply raw performance. They're wonderful pieces of history, and the need to restore and preserve this becomes more important as the years pass by.
You could get some respectable torque out of even 300 cubes with the right combination of parts. Keep the 2 barrel intake, use a larger 2 barrel (I'm pretty sure there are small base to large base conversion plates), use a large Rochester 2g carb (350-400 or so CFM should do the trick for 300 CID, vs the 278 or so CFM the small base has--this is of course @3"), which should keep everything looking original and very little if no additional adjustments to the original linkage. Might need another air cleaner, not 100% positive on that. I believe the small base 2g's used smaller ones so would need to find a larger one. If this is too much trouble, have someone rebuild your OEM Rochester 2g small base for better CFM and performance and work with what you have. I would use one of those scavenger series "Y" pipes for exhaust if it were me. Do some head work and smooth everything over nice for optimizing flow, get a camshaft with a bit more lift and concentrated duration patterns for a powerband between 1500-4000 RPM, and that little 300 CID would probably produce close to 350 ft. lbs. down low (325+ for sure), which would work surprisingly well in a light car with factory gearing and the ST300 trans. Not surprising to me, but to others, that is. I already know what this combination and powerband does, because I've used it before with various powerplants (not a 300, but even a stock 350-2 does well with it). The more torque you can push through it, the better it'll perform (duh). You won't break any land speed records or compete with dragsters, but for a nice street cruiser, it'll get out of its own way and then some. Selecting a good cam with early IVC will bump your dynamic compression, and even with the factory 9:1 pistons could get decent performance out of it without the need for a complete rework with stroking and forged pistons and all that hot mess. Shave some off the heads to bump compression some if you want, but the cam will be your deciding factor on how much DCR you can get, and is the easiest way to squeeze more out of what you have. A torquey cam, decent compression, premium fuel, generous ignition advance and a good 2g will surprise you. :TU:
I like reading these 300 threads, and like hearing what you guys do with these engines, particularly things like the above method for stroking using the AutoTec pistons which I hadn't heard before. Is there a link to those or maybe a pic you could post? Doesn't really apply so much to Buicks but the 300 is the right engine choice when upgrading power in an MGB sports car. The motor that you guys take out to install a 350 or BBB as an upgrade is the right one for us. Opinions vary of course, some are put off by the extra 50 to 80 lbs you give up compared to the Rover or 215 but that iron block is so much stronger, and the extra cubes are so much better. Others are put off by having to install a hood scoop or go to some lengths to get it under the hood but again, I think they are missing the point. Of course we haven't much use for iron heads. Is this a mistake? We are very weight conscious, the entire car weighs about 2200 lbs. but seems to handle weight and power very well. I've personally installed the 215, the 455, and the 340 in these cars and the 300 gives the best balance of ease, simplicity, availability of components, cost, power, etc of any engine choice (I'm not even willing to discuss anything with other than 8 cylinders here as they are nothing but a communist plot :Brow. We've been looking for a nice simple stroker path but the right pistons have always been the issue. Well, that and finding suitable 300 SBB engines of course. Most guys want the '64 with the alloy heads and 4bbl but those have gotten a little scarce. In fact, if I could pick a nice one up for cheap I'd consider keeping it just in case I wanted it later. Not that I'd give up my 340 mind you, that's there to stay (I really should update my avatar). It's really too bad the BOP bellhousing pattern has become a thing of the past, though a 1/8" thick adapter plate can let you use the Chevy pattern. In terms of automatic transmissions this new stuff coming out is muy fantastico. No matter how good a non-electronic transmission is it will never be in the same game with these new ones except as a strictly single purpose, very specific application drag racing transmission. If only we could use them. But there may be hope. Chevy has a long history of racing support and they may have a standalone transmission controller for sale, if not now, perhaps when the new joint venture 10 speed (with Ford of all companies) comes on the market for 2017. More gears are almost always better, but what in the world does anybody need with a 10 speed? I don't know. Ask the man that has one. But I've driven the 6 and 7 speeds and it was enough to convince me. They are becoming pretty common in the new cars. I have an 8 speed behind my 340 and am right in the middle of modifying software code for the MegaShift controller that is wired up to it so next spring I plan to be driving it, but so far have driven it in limp mode a bit. Should be OK. I'm mostly a manual enthusiast myself but the only thing these new autos don't have is the ability to push in the clutch. I'd like to find a way to change that. As far as the usual suspects, I'd definitely go with the 2004r. Say what you like about the switch pitch, a lock-up converter is functionally just about the same and is more efficient as well. In essence you end up with the equivalent of a 5 speed automatic. Pick the right axle gears and it's a winning combination. Regards, Jim
Jim, I am so with you about putting these SBB's in an MGB. Yes, I do have fitment issues, but not due to weight (height and exhaust). I am working on some 215's that could go into MGB's, because it's easier in some ways (just the motor placement actually, but then the transmission hookup is harder or more $$$). And I also have a couple of 300's that might go into MGB's, or back into my Buick. I am leaning toward stroking the iron 4bbl 300 for the Buick and putting the un-stroked 300 with aluminum heads and intake in an MGB. Got all the parts except pistons, in fact. In the real world, the 215's are probably going into Corvairs, where the weight really is critical. And at least 2 of those will be stroked, all will eventually be EFI. Meanwhile, I will be watching here, unless you open up another thread for stroked SBB's. Then I'll watch both. I am an amateur at this, but with the help of these forums (here and MG and Corvair) I have been able to do so much more than I ever would have.
You guys all read this?: https://www.google.ca/amp/www.hotro...-how-to-hot-rod-any-engine/amp/?client=safari
A new thread is probably a good idea since I'd like to say a few things that are specific to the MG engine conversion. Thanks for the comments and I'll start that thread. Jim
It's a good article but is limited by cast pistons and steel shim gaskets for 10:1 compression. Not bad, by any means. So... How's the book coming? Jim
