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Re: Roller lifters input
Russer1,
Around here several of us have used the Isky lifters, the other guys get about 250 hrs before they have them rebuilt. Some say rebuilding is not good, but Isky does it. One friend had his Isky's rebuilt and Isky added the oiling hole to make them the latest/greatest. He had one fail after 12 hrs. This was after getting 250hrs consistently thru the years. He has a big cam big spring psi.. etc. close to .700" and 260lbs on the seat. I would run the same Isky's. Old style and they would fail at 40hrs.. very tiriing to chase that dream. Johnny DCB I went to Schubeck .90s flat tappets and had cam problems.. so now I have the the Roller X's .903 and installing them now. We'll see if this is the answer.. Thats what the pics are of earlier in this thread.. Give Joe a call he is a grreat guy! Nobody.. That is encouraging to hear some are running them and have had success.. and I hope I have the same.. my cam is .685" lift and 260lbs on he seat.. Time will tell.. I need to get back to it.. Later all! |
Re: Roller lifters input
Originally Posted by Mr Gadgets
Johnny DCB I went to Schubeck .90s flat tappets and had cam problems.. so now I have the the Roller X's .903 and installing them now. We'll see if this is the answer.. Thats what the pics are of earlier in this thread.. Give Joe a call he is a grreat guy! |
Re: Roller lifters input
Don't forget to address pushrod deflection. There is a great amount of HP the is lost due to this. At max lift on some profiles there is as much as .100" in deflection. Once the lifter peaks on the profile the pushrod "rebounds" and this can cause the lifter to crash into the flank of the closing side. This can cause a harmonic in the valvetrain and can lead to catastrophic failure.
Chris |
Re: Roller lifters input
Originally Posted by cstraub
Don't forget to address pushrod deflection. There is a great amount of HP the is lost due to this. At max lift on some profiles there is as much as .100" in deflection. Once the lifter peaks on the profile the pushrod "rebounds" and this can cause the lifter to crash into the flank of the closing side. This can cause a harmonic in the valvetrain and can lead to catastrophic failure.
Chris |
Re: Roller lifters input
cstraub..
and what might be the answer for that problem.. Fatter push rods.. mine are around 11" long.. and I know they flex.. but I have clearance issues.. What do you do about the deflection problem? |
Re: Roller lifters input
I am fortunate to work for who I do and because of that I get a wealth of feedback, both good and bad, back from what is the creme of de creme of engine builders; a few of which frequent this board.
I added the deflection part so that for those that think a high dollar lifter is going to be all you need for a bulletproof valvetrain are not disappointedn't get blamed in the future if a failure happens. As I know Laz and a few others will agree with me, there is no such thing as a bulletproof valvetrain but matched components are key to longevity. Pushrod weight was "marketing hype" a few years ago, less is better. I used it also. But now with Spintron testing it has been proven the few grams of weight saved on the valvetrain with light pushrods is not worth the 20 to 40HP that you are loosing due to deflection. None the less the extra stress that the valvetrain is going through. The "boys" in NC run 7/16" to 9/16" stuff. Some is single taper some is dual taper. For most of you here running with blowers and NA engines a 7/16" single taper would suffice with the more severe stuff using the 1/2" diameter stuff. Mr. G, at 11" and probly with 3/8" stuff, yes you have deflection no doubt. You have clearance issues, I understand, but let me ask you this. Is it worth possible engine failure due that could have been avoided with some clearance grinding and an upper engine disassembly? At 11" you need at least some 7/16" single taper stuff. Don't get caught up it the lightweight game. Racing you can push the enevelope, for most of you this isn't the case. You need parts designed for durability. For a fact, one of the top Funny Car teams has some of the heaviest lifters in their car. The bodies have been in there for 3 YEARS!!! Just the axles and rollers assemblies have been changed. Additional oil. Hell yes. Spray bar systems in the valve covers, in the lifter valley, and built into the oil pan are all good ideas and good insurance. Hope I have helped. Chris |
Re: Roller lifters input
Originally Posted by cstraub
I am fortunate to work for who I do and because of that I get a wealth of feedback, both good and bad, back from what is the creme of de creme of engine builders; a few of which frequent this board.
I added the deflection part so that for those that think a high dollar lifter is going to be all you need for a bulletproof valvetrain are not disappointedn't get blamed in the future if a failure happens. As I know Laz and a few others will agree with me, there is no such thing as a bulletproof valvetrain but matched components are key to longevity. Pushrod weight was "marketing hype" a few years ago, less is better. I used it also. But now with Spintron testing it has been proven the few grams of weight saved on the valvetrain with light pushrods is not worth the 20 to 40HP that you are loosing due to deflection. None the less the extra stress that the valvetrain is going through. The "boys" in NC run 7/16" to 9/16" stuff. Some is single taper some is dual taper. For most of you here running with blowers and NA engines a 7/16" single taper would suffice with the more severe stuff using the 1/2" diameter stuff. Mr. G, at 11" and probly with 3/8" stuff, yes you have deflection no doubt. You have clearance issues, I understand, but let me ask you this. Is it worth possible engine failure due that could have been avoided with some clearance grinding and an upper engine disassembly? At 11" you need at least some 7/16" single taper stuff. Don't get caught up it the lightweight game. Racing you can push the enevelope, for most of you this isn't the case. You need parts designed for durability. For a fact, one of the top Funny Car teams has some of the heaviest lifters in their car. The bodies have been in there for 3 YEARS!!! Just the axles and rollers assemblies have been changed. Additional oil. Hell yes. Spray bar systems in the valve covers, in the lifter valley, and built into the oil pan are all good ideas and good insurance. Hope I have helped. Chris |
Re: Roller lifters input
Laz,
Terry's stuff is top notch I agree. It's hard to explain the value of a $20 pushrod to someone when they are out there for $100 a set. People think you are ripping them off when in fact you are looking out for them. Thanks for adding your recipe at the end there. It just goes to say, pay me now or pay me later. Chris |
Re: Roller lifters input
Originally Posted by Johnny DCB
I'll be happy with 1000 but it will be closer to 1300 I hope.Atleast thats the mark we're shooting for.
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Re: Roller lifters input
Laz,and or, Chris, what's your opinion of the Crower, 68806 and 68848 valve springs?
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