high lift cam in olds 350 question about Push Rod length
10

Asked by Guru3WY7S Jun 30, 2020 at 10:24 PM about the 1971 Oldsmobile Cutlass

Question type: General

I put a higher lift cam (RV type) into my 1971 olds cutlass. bone stock engine with only about 3000 miles on it) For them to make a "higher lift" to fit into the olds block, the Base cirlce's of the lobes have to be smaller (by .150") so the lifters are now .075" down in the hole, making the distance from the lifter to the rocker are .075 longer. it seems I need push rods that are .075" LONGER to keep the geometry straight and the valves to not open .075" short.  am I explaining this right ?? since putting in this cam, the car has no bottom end (it is only 205/214 @ 50, .448/467 lift. I am thinking because of the Stock Shorter pushrods, I am gaining the duration but not the lift. get it ?? cam is installed straight up, not advanced) (also 2.56 gears don't help the matter).   any educated opinions on this will be appreciated.   Thank you

6 Answers
10

Guru3WY7S answered 4 years ago

the cam came ALONE (Elgin). I used new aftermarket crane lifters. was lubed properly, not my first rodeo. the lobes are fine, but SENSE tells me when a lifter and push rod goes .075 Farther down in the hole than it originally was, SOMETHING has to"make up" the difference. and the "Middling" of the hydraulic lifter will NOT take up .075".

1 people found this helpful.
Mark helpful

F_O_R answered 4 years ago

Read this. http://victorylibrary.com/mopar/regrind-c.htm

1 people found this helpful.
Mark helpful

F_O_R answered 4 years ago

And this. https://blog.trendperform.com/how-to-measure-pushrod-length-and-optimize- valvetrain- geometry#:~:text=Inspect%20the%20position%20of%20the,pushrod%20length%20for%20str eet%20engines.

Mark helpful

F_O_R answered 4 years ago

Lastly. https://www.hotrod.com/articles/how-to-measure-for-correct-length-pushrods/

Mark helpful
103,435

KenF answered 4 years ago

Your instinct is right, any change in the diameter of the base circle will affect pushrod length. Some old cam books I had showed how to measure for new pushrod length but I don't have those anymore. Try this compcams guide, starting around page 6. http://www.compcams.com/pub/media/productattach/1/4/145.pdf

1 people found this helpful.
Mark helpful

Your Answer:

Related Questions

  • high lift cam in olds 350 question about Push Rod length 6 Answers

    I put a higher lift cam (RV type) into my 1971 olds cutlass. bone stock engine with only about 3000 miles on it) For them to make a "higher lift" to fit into the olds block, the Base cirlce's of the l...

    1971 Oldsmobile Cutlass

    -

    General

  • 1964 Olds Cutlass 330 4v automatic 5 Answers

    Can ANYONE tell me if the vacuum hoses for the carburetor + old time PCV regulator in valve cover & brake booster where colour coded or had the AC delco GM numbers on them? I've heard all are corr...

    1964 Oldsmobile Cutlass

    -

    General

  • 1979 Oldsmobile Cutlass Supreme Engine and Transmission Swapping? 6 Answers

    I have a 1979 Oldsmobile Cutlass Supreme with a 4.3L 260 V8 Engine. I was wondering what kind/size of transmission did they install with the 260 engine? Also if I change to a 350 engine what kind/siz...

    1979 Oldsmobile Cutlass

    -

    General

  • Vins for 1972 Cutlass 6 Answers

    I am in the market for a 72 cutlass. There are so many cloans that I want to be able to identify what the car was born as. What part of the VIN identifies supreme, 442 and all the other models and...

    1972 Oldsmobile Cutlass

    -

    General

  • HOW MANY 1966 OLDS 442 WERE BUILT IN JULY 1966 10 Answers

    PRODUCTION NUMBERS

    1966 Oldsmobile Cutlass

    -

    General

Cutlass

Looking for a Used Cutlass in your area?

CarGurus has 1 nationwide Cutlass listings and the tools to find you a great deal.

Postal Code:

Shortcuts

Search Oldsmobile Cutlass Questions

CarGurus Experts

  • #1
    bluRAYwhale
    Reputation
    230
  • #1
    James Sparrow
    Reputation
    230
  • #3
    Gene Arnett
    Reputation
    140
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Oldsmobile Cutlass Supreme
5 listings
Used Oldsmobile 442
1 listing
Used Chevrolet Caprice
1 listing
Used Chevrolet Chevelle
5 listings

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.