I have a Silver Streak I have been driving for a few years, I pulled it out of a pasture where it sat since 1963 and got it running. It's been a great experience and a fun beater car but the time is coming to do some powertrain upgrading. The car still has the original flathead 8 with a hydra matic. The motor and tranny work well and are unrebuilt. I went through everything else that you have to do when bringing an old car back to life. I was pleasantly surprised to see how the motor has held up these past few years, tranny works well also. The problem I'm having is that the car just isn't fast enough to maintain Hiway speeds. It feels like I'm pushing it to do more than 60-65. That is running about 3 grand on the tach and with such an old original motor it's just not what I want to run at. It really wants to run at 2500 which is about 55mph. Most of the time it's ok and I don't really mind it but there have been a couple of times when people have been tailgating me and making very dangerous passes on 2 lane road, just about taking everybody out in the process of making a stupid pass. It will soon be time for a v8, tranny and probably a rear end swap. I love Oldsmobile motors and have several good 60's v8's. It's been on my mind to use one of these. I think it would be cool to have a rocket in a Pontiac. The motors I'm thinking of are an early 70's 455 with a turbo 400 or a 63 394 with the tranny that came with that motor (jet away?) The 63 tranny doesn't have a very good reputation so I'm not feeling all that great about that. All of that to ask my question, would I be able to stay with the hydra matic with a v8? Possibly the 63 motor? I like the tranny and I know they are good in their own right but I'm unfamiliar with what they can be used with. Sorry for the long explanation but I thought it would be good to include the details. Looking forward to the good Hamb input. Thanks Jon
Why not a 389 and 400 automatic, Keep it all Pontiac. Or keep the straight 8 and hydromatic and change the rear end ratio so it would run lower RPMs on the highway.
If it all works now, I'd change just the rear end. Make it one that could live up to a v8. Get a ratio that would give you the highway speed you want. This should be a weekend project if you plan ahead and have some help. Later you could put in a new v8. Meanwhile you'd be driving it.
I believe the center section of the Pontiac rear end will interchange with Oldsmobile into the late 50's. Shouldn't be hard to find a good ratio center section.
Interesting, I have considered changing out the gears but I didnt know if the motor was just too tired or what. I havent had a straight 8 before so I'm not really sure how they are supposed to run power wise. . I have read that they dont have very much horsepower. However i've always thought that they must have been able to do a lot better than my car can presently. I like the idea of keeping the motor and trans, most people have never even seen one of these motors that runs so its cool to let people see that and keep something old going. Do you think a center section from a 59 olds would work? I have some of those.
Put the Olds engine in it and fab up some Pontiac valve covers on it like these hokey assed guys do with SBC motors in Fords!
No, that's the early style chuck in your car. Here's a good place for some help with a differential that will fit your car. http://forums.maxperformanceinc.com/forums/forumdisplay.php?f=426 KK
Thanks I will look into that, still like the idea of more power, the tranny shifts into all 4 gears and doesnt appear to be slipping at all, do you think it could somehow be robbing the motor of power or holding it back? The motor runs good and spins up fine in nuetral but just doesnt seem to have a lot of power when engaged.in gear. I would assume that these cars went moderately fast back in their day. btw, if I do choose to do and olds motor I will definately not disguise it as a Pontiac motor. Was just thinking this would be a good use of some good stuff I have.
If the engine is in good shape I would mill the head it's only 6.5 to one and change the gear ratio. A straight 8 just looks cool.
I've been doing some more reading and will pursue gears before anything else. I like the straight 8 a lot and am not looking for more work to do, Lord knows I have enough irons in the fire always. Sunbeam, you reminded me of something. I had the privilege of meeting the man (Charlie) who drove this car back in the day. He is actually who I bought it from. He told me this car was his hotrod in the 1950's. He said he parked it in the 60's. I remember him mentioning that he had the head shaved back then. I brought the car home and put it in the line with my other old cars and by the time I decided to work on the car Charlie had passed away. However, I was able to meet his younger brother who told me he remembers being a very young teenager and flying down the road with his older brother in that car,he said he remembers going over 100mph. cool. I can't see how this car would do that unless the motor was just screaming. It was probably just 10 years old or newer at the time and that would make all the difference I'm sure. I will see if gears help. I'll ask a stupid question, is there anything in the tranny that can be holding the car back or limiting power? Maybe the motor is just more tired than it seems. It runs good but doesn't seem to have a lot of power and I'm just imagining going to more of a road gear isn't going to help that, it seems that would make it really doggy. It's just probably how they ran I guess.?
I would do a compression check and adjust the transmission bands First. Max torque was @2000 hp @3800
Change the points to a Pertronics ignition system with the coil, it will run much better, I did this to a 54 Buick and it made a world of difference. And yes, it had new points, plugs, wires, and condenser before the change.
Check compression and oil pressure. How many miles on it? 80000 was about the life of the motor, maybe 100000 if you were lucky. They were a long stroke high torque motor, powerful but not snappy fast. Should get you around just fine if it is in good shape. Change rear gears to bring down RPMS. If you really want performance in the modern sense a V8 swap is the way to go. My preference would be to keep the straight eight especially if I had a performance car for days when I felt like going for a rip.
Good input I will do a compression check. Petronix is a good idea as well. I will have to learn about the tranny bands. How hard is that to do? Any resources you guys can recommend for that info? So those motors were rated for 200 hp? Will start looking around for a center section. I have a 55 Olds parts car. Had a 324 in it, I believe with an automatic. That might be good? Thank you
Btw Yes I have some performance stuff to rip around with. I wouldn't mind staying original with this car, just don't want to get ran over or be a road hazard lot of impatient and non courteous drivers have moved up here in the last few years. Driving manners are different now unfortunately
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