How many here had to change pushrod lengths with your mods?

gnx547

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Sep 26, 2006
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I have a question about pushrod length. Not to long ago I bought a 91 Lx 5.0 and it has an FTI cam in it 224/228 Duration at .050 .536/.528 Lift 110* LSA, The block is stock and bored .020 over with srp pistions, AFR 165 heads (never machined) with 1.7 rockers, cobra intake and the deck height has not been machined..

My question is: Is the FTI cam base circle smaller than the stock cam in the 302? Does the FTI cam effect push rod length? The previous owner installed STOCK length harden pushrods.

I know you have to measure to get the correct length but I am curious and seeing how many here had to go with a different length? Do many here still use the stock length push rods, with aftermarket heads and the block not being deck? In this case the block deck height hasn't been changed and if the base circle of the FTI cam is the size same as stock cam, then most likely the stock length pushrods are correct?
 
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gnx547

Member
Sep 26, 2006
283
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I have a question about pushrod length. Not to long ago I bought a 91 Lx 5.0 and it has your FTI cam in it 224/228 Duration at .050 .536/.528 Lift 110* LSA, The block is stock and bored .020 over with srp pistions, AFR 165 heads (never machined) with 1.7 rockers, cobra intake and the deck height has not been machined..

My question is: Is the FTI cam base circle smaller than the stock cam in the 302? Does the FTI cam effect push rod length? The previous owner installed STOCK length harden pushrods.

I know that you have to measure to get the correct length but I am curious how many here had to go with a different length? Do many here still use the stock length? Without the blocks deck height being machined? In this case the block deck height hasn't been changed and if the base circle of the FTI cam is the size same as stock then most likely 50% the stock length pushrods are correct?
 

5spd GT

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I had AFR heads on my stock 302 block (no deck, no rebuid, nothing) and an FTI cam. 1.6 Stud-Mounted Scorpions.

He sent me the correct 6.250" hardened pushrods to match.

Stock is 6.272".

Is your rocker making a thin lateral patch, in the center? If so, your good to go:nice:
 

gnx547

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Sep 26, 2006
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Is your rocker making a thin lateral patch, in the center? If so, your good to go:nice:
What do you mean by making a thin lateral patch in the center? How do I check for that?


With your FTI cam, hows your valve train noise? Is it pretty noisy or quiet?


Who sent you your correct push rods?
 

5spd GT

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What do you mean by making a thin lateral patch in the center? How do I check for that?


With your FTI cam, hows your valve train noise? Is it pretty noisy or quiet?


Who sent you your correct push rods?
Valvetrain noise is actually pretty quite:shrug: I have almost forgotten what a stock one sounds like. However, it is not uncommon at all to have a sewing machine sound with more aggressive cams...

Ed Curtis sent me the pushrods with my cam/lifters/timing chain/heads/roller rockers/etc.

No measuring, he knew what works, because he does it day in and day out, and knows the tolerance differences.

As far as the valvetrain geometry, maybe this link will help you:nice: Check out post #5...

http://www.ls1tech.com/forums/showthread.php?t=327734
 

gnx547

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Sep 26, 2006
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Thanks for the info, It makes me wonder if I need to use the 6.250 instead of the 6.272 pushrods? Your mods are very similar to mine.


I was wondering what are the specs of your FTI cam ? Do you have the AFR 165 heads?
 

5spd GT

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Most of the time custom cam grinders prefer not to give out the 'custom' specs, but I can give you basic info:)

.560/.556 - 224/224 duration.

Yep, I have AFR 165's with the 7/16" studs/spring upgrade/viton seal upgrade.

If your rocker tip is on the exhaust side (outside of the engine), you have to long of pushrods, and could possibly benefit from 6.250" as far as valve guide life is concerned. Just look at that link above, and it should help you determine if you need a different size.

I have stud-mounted heads, not pedestal mounted AFR's (like stock style).