Solid flat tappet

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BTZ201
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Solid flat tappet

Post by BTZ201 »

Hi guys,
I recently broke in a solid flat tappet cam for the first time. I have done plenty of hydraulic flat tappet cams in the past with no problems.
My question is after breaking in the solid and putting a few street miles on it, I adjusted the valves and found them out approximately. 005-.007 out.
Is this normal?
Motor is a stock bottom end 350 with a pair of rebuilt older bowtie heads shaved to approximately 60cc chambers.
Thanks,
Brent
rebelrouser
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Re: Solid flat tappet

Post by rebelrouser »

That would make me nervous. At this point do you take the time to pull the lifters and see if they are breaking in properly, or just cross your fingers? I have removed the valve covers and started the engine, at a fast idle if the lifters are rotating the push rods usually rotate as well. I guess the big question for mew is what kind of spring pressures were the head set up with?
Walter R. Malik
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Re: Solid flat tappet

Post by Walter R. Malik »

BTZ201 wrote: Wed Aug 10, 2022 9:08 pm Hi guys,
I recently broke in a solid flat tappet cam for the first time. I have done plenty of hydraulic flat tappet cams in the past with no problems.
My question is after breaking in the solid and putting a few street miles on it, I adjusted the valves and found them out approximately. 005-.007 out.
Is this normal?
Motor is a stock bottom end 350 with a pair of rebuilt older bowtie heads shaved to approximately 60cc chambers.
Thanks,
Brent
Sometimes, especially if the valve train parts have never run together with each other before. After setting them that second time after a few heat cycles, they should only change a thou or so .
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lefty o
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Re: Solid flat tappet

Post by lefty o »

put another 50 miles on it, and check them again.
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Re: Solid flat tappet

Post by F-BIRD'88 »

Set the lash tighter than cam card lash while breaking in the cam.
BTZ201
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Re: Solid flat tappet

Post by BTZ201 »

Thanks for the responses, haven't had any time to put some miles on it yet.
Fingers crossed its not going flat!!!
If it survives, its sticky tires and off to the track....😀
It pulls pretty strong past 6k, would be happy to see 12sec 1/4 mile time.
Its in a heavy 1975 gmc, time will tell....
Thanks,
Brent
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Re: Solid flat tappet

Post by Monza355 »

Out of curiosity what camshaft and lifters did you use in your 350 engine ?
BTZ201
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Re: Solid flat tappet

Post by BTZ201 »

Summit ct101.
I believe its an old elgin grind.
.050 intake 256
Exhaust 264
.504 lift for both.
Using 1.6 rockers on intake
105 lobe separation.
Heads have pretty extensive port work, only have seat of the pants flow #'s...
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Re: Solid flat tappet

Post by 1972ho »

Are your rocker setting off on low side are on the high side and did you set them using the cam card hot setting it also will make a difference aluminum heads and iron block .
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Re: Solid flat tappet

Post by 1972ho »

1972ho wrote: Mon Aug 15, 2022 11:52 pm Are your rocker setting off on low side are on the high side and did you set them using the cam card hot setting it also will make a difference aluminum heads and iron block .
. So if you set them cold subtract.006 from hot setting aluminum heads iron block.So if you set them cold using the hot setting they will change by .006
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