BAFRAYD

My 74 Cutlass S started popping through the carburetor under lite acceleration. I had my mechanic take a look at it and he verified my concerns that the camshaft is bad. I had planned on running this engine while I had a 455 built to replace it. The car and engine only have a little over 90k miles and seem in great shape otherwise. I don’t yet have the coin for my 455 yet so I would like to replace the cam so I can continue driving it while I wait. My mechanic is advocating that I just use a stock replacement cam something like this: http://www.summitracing.com/parts/slp-kct-707/overview/

I'm kind of leaning towards something a little “better" if there is such a thing that will work well without making any changes to my current setup.

The 350-4bbl engine is completely stock other than a Pertronix electronic ignition conversion and a Summit 2.5" dual exhaust. The exhaust isn’t installed yet but will be soon. I have to drive with hand controls so I can’t manually shift the transmission, therefore it’s important to use a cam that is going to be effective with the stock shift points. My car has a TH350 transmission and 2.56 gears. I plan on towing a small trailer from time to time that weighs about 1500 lbs.
My questions are:


Would you go stock or is there an aftermarket grind that can do everything better?


If you went for a stock replacement, what brand would you use?


Anything else I should replace while I am at it?



Any other alternatives I might be missing?
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- Eric

nsnarsk65cutlass

Stock replacement is what i would do thats just me, that lobe-s material went thru the rest of the engines oil system,so if you are just replacing the camshaft i'd keep as cheap as possible.Nick

455man

I'd think there are better grinds 30yrs later that would work with your stock setup. check with CutlassEFI. But as Nick said you probably have cam shavings in your whole engine.

BAFRAYD

Ugh, not good. I guess it would not be wise to throw anymore $ at this engine. I'm thinking it might make more sense to raise cash for a good running replacement.

jcdynamic88

put another stock cam in it.over the years I have had to replace many,many cams because of a bad lobe,mostly on late 60s small block chevys and never had an issue because of the worn material getting into the engine.it should end up in the filter.you could just remove that plug wire for a short time , if the cam is replaced make sure an oil with zinc is used in conjunction with the break-in additive or you will have another bad lobe.

barnfind

Maybe a magnet applied to your oil filter to help keep those particles in there.

455man

I've got a magnetic oil plug.

Smitty275

I have many used factory stock cams here. $20 gets one. Basically that covers shipping. For $69 get a new set of lifters and the cam.

olds 307 and 403

Very rarely do Olds stock cams fail. You should be fine with the motor as long it was decently maintained. Get the mechanic to stick an oil pressure gauge on it. Cutlassefi does custom grinds for low compression Olds V8's like yours. The stock cam is plain pathetic but don't go too big either. A stock 307 vin 9 or smog 455 cam will also work well.

BAFRAYD

Thanks everyone for all the good information.

I am putting an oil pressure gauge on it this weekend. What kind of oil pressure should I see at a operating temp idle?

If I recall correctly, used cams don't need to be broken in like a new one? How is the track record of used cams? Are these good ones that were upgraded for better performance?

Smitty275

Basically correct in the new cams don't need the break in like s new cam would. But since your putting new lifters on it you should still do a short break in period.
All the used stock cams I have here are in good shape. They came out of engines that were to be rebuilt.

olds 307 and 403

Your oil pressure should be 15 to 25 idling in park. Around 40 to 55 at 2000 rpm. Get a used smog 455 cam from Smitty.

BAFRAYD

Finally got a chance to put an oil pressure gauge on it, 20psi at idle in park @ 180*, so that is good news.

While at my local auto parts dealer today, I ran into a former Olds guy. He saw my Cutlass and started asking about it. We got to talking about my issues with it and a test drive was soon under way. To him it didn't sound like a camshaft issue. Eventually we ended up back at his house with the hood opened and air cleaner removed. Right away he started pointing out vacuum lines with no end and an open vacuum port. Neither of which were pulling vacuum. He also noted that the secondary's weren't opening under WOT. He retarded the timing a little bit with the distributor and the pop through the carb went away, but the slight miss at idle got worse. He didn't have time to help me much more today but said that if I brought the car by his house next week with a diagram, he would help me redo my vacuum lines and set the timing and such. Great news to me! Even better news… The guy also had an Olds 350 for sale. Check it out: https://classicoldsmobile.com/forums...tml#post692217


Maybe a new mechanic is in order? I can’t believe my current one missed these issues. I’m also miffed as to how it got this way since it ran good when I bought the car.

bkeese

You think!