I see that there may be differences between aftermarket heads for hydraulic roller vs flat tappet. What’s up with that ??
I’ve seen heads listed as flat tappet and hydraulic roller.fully assembled aftermarket heads - the difference will be in the valve springs
is that the only difference?I’ve seen heads listed as flat tappet and hydraulic roller.
I answered in post 2. When ordering a set of aftermarket heads, you get a choice. Roller version or flat tappet version. The spring is the difference.is that the only difference?
Yes will do. ThanksCut to the chase- call the supplier and ask them.
Hydraulic roller lifters are heavy compared to a FTH. It takes more spring to control that heavy lifter at rpm. I can't say for sure but I have heard that retro rollers for LAs are the heaviest.
I have heard quite a few guys here on FABO complaining about roller lifters. And
have heard a few guys extolling solid rollers.
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I've been running the same hydraulic FTH lifters since about 2004 when I installed a Hughes HE 3038AL cam with specs of 276/286/[email protected], and lifts of .549/.571 (1.6 arms) using Hughes 1129(IIRC) dual springs. I've been shifting it at up to 7000/7200. I got no complaints.
jus saying.
For "general principle" and especially "dem kinda" RPMs w/FTH lifters, I bestow upon you a heartfeltHydraulic roller lifters are heavy compared to a FTH. It takes more spring to control that heavy lifter at rpm. I can't say for sure but I have heard that retro rollers for LAs are the heaviest.
I have heard quite a few guys here on FABO complaining about roller lifters. And
have heard a few guys extolling solid rollers.
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I've been running the same hydraulic FTH lifters since about 2004 when I installed a Hughes HE 3038AL cam with specs of 276/286/[email protected], 230/[email protected], and lifts of .549/.571 (1.6 arms) using Hughes 1129(IIRC) dual springs. I've been shifting it at up to 7000/7200. I got no complaints.
jus saying.
Now that's a term for FTHs I've never heard...squishys
"squishified" ....Is that like nitriding, or treating hot forged steel to some liquid inert gas specialty performance or strength enhancements? No WONDER they rev so high! Lol.the lifters have never been squishified
Now that's a term for FTHs I've never heard...
YR started it, He makes perfect sense tho; I just rolled with it,lol.Why put a squishy shock absorber in the valve train if you want performance?
The big thing is that the roller lifters are taller. This changes the angle of the pushrods going through the heads and will bind and scrape in the tubes of the heads. Edelbrock makes heads with that clearance. At least this is the case with the LA heads. I had to modify mine. I was too cheap to by new made for roller cams. You have to be careful not to cut into the intake runners.I see that there may be differences between aftermarket heads for hydraulic roller vs flat tappet. What’s up with that ??
I run my squishys at near-zero preload, so if or when they pump up, they behave like a solid. Since my pushrods have never fallen out, and the minor ticking never changes after a blast; I have to assume that the lifters have never been squishified. The proof, I think, is in the 93 mph Eighth-mile, with that smallish 230 cam
I see that there may be differences between aftermarket heads for hydraulic roller vs flat tappet. What’s up with that ??
The big thing is that the roller lifters are taller. This changes the angle of the pushrods going through the heads and will bind and scrape in the tubes of the heads. Edelbrock makes heads with that clearance. At least this is the case with the LA heads. I had to modify mine. I was too cheap to by new made for roller cams. You have to be careful not to cut into the intake runners.
View attachment 1715733924
Roller lifters are heavier so they need stronger springs to keep them from bouncing (floating) off the cam..
About as simple as I can explain it...
I disagree. Lifter weight has a LOT to do with spring selection, especially when you consider the inertia of the lifter at high RPM. It will take a lot more spring to control a heavy lifter, than a light weight lifter (one of the reasons high RPM engines need light valvetrain components)....think about it critically for a moment, I'm sure it will make sense.Lifter weight is pretty much inconsequential, especially when it comes to spring loads.
I disagree. Lifter weight has a LOT to do with spring selection, especially when you consider the inertia of the lifter at high RPM. It will take a lot more spring to control a heavy lifter, than a light weight lifter (one of the reasons high RPM engines need light valvetrain components)....think about it critically for a moment, I'm sure it will make sense.
Simple illustration: Shake a can of soda at a steady rate of 5 shakes per second, now try to do the same with a gallon of milk....it will take a lot more force to control the milk because it weighs more (more inertia). Now imagine the magnitude of a small increase in weight at 7000RPM....I hope that helps.
Here is the porting I did. You can see how the push rod tubes interference. Opening them you have tobe very careful in the runners & in the tube. You can see them on the top of the whole head. The holes at the top close to the outside.I see that there may be differences between aftermarket heads for hydraulic roller vs flat tappet. What’s up with that ??