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Hi All,
Hope you are all doing well and finally starting to get to car shows!
So I'm getting ready to pull my engine for some repairs. I have a 72 Model, Cutlass Supreme but 71 build with a 350 4 BBL Dual exhaust. I had the engine rebuilt in 2007 and it only has 37,000 miles on it. But it is having oil pressure issues, so I am replacing the Oil pump and checking the bearings and throwout bearing. I don't know if the rebuilder back in 2007 ground the original cam shaft or replaced it, since the engine only had 113,000 on it at the time of rebuild. Since I am replacing some parts I wanted to know what people used for cam shafts, with thier engine rebuilds? I'm not building a race car, it is staying stock as a nice highway and back road cruiser.
A quick back history on rebuild. I had the engine bored 0.30 over, hardened sleeved for unleaded gass. Installed 70 pistons for low end torque. Installed Thornton split exhaust cast iron manifolds ported and polished and mated them to Dual 2.5 X pipe exhaust. The engine also has a date coded Rochester Quadrajet 4BBL stage 1 jetted and needled. Aside from that nothing else was changed from stock. I'm installing a stock flow Melling oil pump. Ans a Flowkooler Hi output water pump.
I Would welcome recommendations of what you guys are stock ( NON racing or Resto mod ) running in your engine and manufacturer.
The camshaft choice will greatly depend upon the compression ratio. Do you know what pistons were used during the rebuild? Not all 1970 pistons are manufactured the same, as in cast pistons are typically short on compression height whereas forged pistons are usually correct.
My engine was built with "factory 10.25:1 replacement pistons" but due to the short height, thicker aftermarket head gaskets, larger than anticipated combustion chambers, and no block decking the real compression ratio is in the high 8.x to 9.0 range and no where near 10.25:1.
Hi Kenneth, That was my Dad's name ! much respect sir !
I have to locate my reciept book with the engine specs to be spacific. It is the Numbers matching 350 and was all stock before the rebuild. Car was power optioned with A/C super cool A/C with the high power switch and power windows and breaks. It was also originally a single esxuast car. and was aslo after the rebuild. I switched to the dual exhaust two years later if that helps. I will see if they noted the specifics on the rebuild info. Here are the pictures after the teardown back in 2007 before the rebuild
Thanks, Tony
Sorry, Gathering information as I go. I'm really kind of new as far as the cars mechanics. The trans is the original TH350 3 speed automatic with floor shifter. Not sure what the converter would be and as far as the rear gears that is stock too a 10 bolt 303? But I couldn't get the number off it since the car spent 19 years in maine and rear axel had been undercoated and very rusted under the coating ! Thanks Ziebart ! The trans and rear have never been out of the car or changed as far as I know. My Dad, the original owner passed away 22 years ago and did not keep the maintanance records. Or they were thrown out by me Family up in Maine. We bought the car used so no window sticker.
Tony, I would recommend this cam grind to maintain good torque and idle quality, I like the Comp Brand products and this would be an improvement over stock.
This is an "off the shelf" cam. You could op for a custom grind. Some folks don't appreciate a dual pattern cam, but I had a similar Engle grind that I used in a 330 Oldsmobile motor that had 9:1 compression, It ran strong.
Rick,
Is this the one that you would recommend since I have the original 71 350 small block in the car, with 70 pistons which I switched when we rebuilt the engine back in 2007.
I'm not looking at creating a race car just a good reliable cruiser.
Tony, the cam link that you have posted is in my opinion a little too much for your car the way it is configured, Stay with a mild grind like I posted and your car will still have the strong low speed torque that it needs. Good luck with your motor. I am really interested in what you discover is the source of your low oil pressure. I have not seen many oil pump failures on Oldsmobile engines,
June 16th, 2020, 05:41 PM
What cam are you using?
