1956 olds 88 engine problems

[Guest AAM]

I have a 1956 olds 88. I purchased it 4 years ago from a family member who recently had the engine rebuilt. two years ago, the engine starting knocking and I had to have the cam and lifters replaced. Last year, I had to replace the cam again. I only drove the car 1500 miles. Whats causing the cams to go bad?

[rocketraider]

Original cams were kinda soft and would wear quickly.

However- I think your situation may be oil-related. What brand/weight oil are you using? Modern oils have little to no anti-wear additives as they are simply no longer formulated for flat-tappet valvetrains.

Recommend an oil with ZDDP additive package which will include most Diesel oils or some private-brand racing oil formulas.

[Guest AAM]

Thank you. I'm currently using 15W40 based on the recommendation of the mechanic. I'm not sure of the brand but I'll find out. I'll be sure and mention the importance of the ZDDP additive. Thanks again.

[Tedd Thompson]

Original cams were kinda soft and would wear quickly.

However- I think your situation may be oil-related. What brand/weight oil are you using? Modern oils have little to no anti-wear additives as they are simply no longer formulated for flat-tappet valvetrains.

Recommend an oil with ZDDP additive package which will include most Diesel oils or some private-brand racing oil formulas.

X2 what rocketraider said, this is what happens when an older engine isn't broken in with a high zinc content oil. 1956 for some reason came new with softer cams than previous engines of the same design, but I believe your problem lies in the break in proceder......Tedd

[Guest AAM]

Thanks for the information

[Guest chuck56]

I had a 56 Olds in 1956 and had trouble with the lifters. Since I bought it off of a car lot, the owner said after replacing them twice, he could not do it again. I put in a Harmon Collins cam and solid lifters since I wanted to beat my friends 56 poncho and thought I had solved the problem. After about a week, one of the push rods came out from under the rocker arm and I had to replace it. Since there is no adjustment on the rocker arm, you had to pull the intake manifold to get to the adjustment on the lifter. The new push rod lasted another week and the same thing happened; I decided the new cam was soft and the lobes were wearing. I put the std cam back in and a new set of hydraulic lifters. My dad liked the car and said he would buy it, I was just driving it too hard. I agreed but said I was done working on it. After several months he had no problems, I borrowed it for a trip and the lifters started clicking. I stopped at a gas station in a small town that happened to be an Olds dealer. When I asked, he told me about a factory bulletin, the oil pump has a metal plug in it that comes loose and sucks air, starving the cam, lifters, etc of oil. The pan was pulled, the plug was laying in the bottom of the pan, suggest you check it out. Chuck:eek:

[NTX5467]

If the oil you're using is 15W-40, the only type of oil with that viscosity rating is "diesel" oil, as in Delo 400 or Rotella T. Even recent oil analysis (- Bob is the Oil Guy . . . click on "Forums", then "Virgin Oil Analysis" in the list of forums) indicate that these oils still have very sufficient levels of zddp for flat tappet cams and lifters. When CompCams came out with their original recommendation for oil for their camshafts, it was "Rotella T or synthetic" oil. The synthetic diesel motor oil is uniquely 5W-40.

Interesting about the service bulletin!

Just some thoughts,

NTX5467

[Guest AAM]

Thanks for the information!

[Guest pete324rock]

Was the replacement cam another dud? A possibility. I had a cam go sour too. See the H.A.M.B. for lots of tales on Olds cams and valvetrain and the heartaches they bring.