454 valve float

Hi Guys,

just swapped in a new hydraulic roller (Comp Cams 230/236 at .050", 112 deg LC, .547" lift intake /exhaust) into my 454.
Dyno results were about as predicted: 482hp at 5500, 500 ft lb at 4600 (but over 490 ft lb from at least as low as 3500 (didn't get figures from lower revs). I was expecting a little more hp, but valve float occurred at 5500. I have the Comp Cams #26120 beehive springs with titanium retainers, which I thought would prevent any valve float until well over 6000. These are rated at 155lb closed and 358lb open at this valve lift. These springs have been run for a while with a less radical cam, so have probably lost a bit of pressure.
Obviously, I need either stiffer springs or some weight loss from the valvetrain. I thought of putting in the Comp Cams spring locators which have a lip on the inside of the spring base - they are .060" thick. This still leaves a good .060" of clearance before coil bind. I also thought of swapping the stock 3/8" pushrods for the Comp Cams Hi Tech thin-wall chrome-moly pushrods to save a little weight in the valvetrain. They are Comp Cams lightest pushrods. Do these two ideas sound reasonable, or is the pushrod thing a waste of money. Titanium items are frighteningly expensive!
I would like to be able to turn another 300-400 revs, which I think it would do. The hp was still going up steadily by 3-4hp per 100 revs until valve float, with no sign of the curve flattening out at 5500rpm. I think the engine has got an honest 490+hp in it - just bragging rights, of course!!
What do the experts think??
Thanks, Chris

Quote:

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Originally Posted by grifo7

Hi Guys,

just swapped in a new hydraulic roller (Comp Cams 230/236 at .050", 112 deg LC, .547" lift intake /exhaust) into my 454.
Dyno results were about as predicted: 482hp at 5500, 500 ft lb at 4600 (but over 490 ft lb from at least as low as 3500 (didn't get figures from lower revs). I was expecting a little more hp, but valve float occurred at 5500. I have the Comp Cams #26120 beehive springs with titanium retainers, which I thought would prevent any valve float until well over 6000. These are rated at 155lb closed and 358lb open at this valve lift. These springs have been run for a while with a less radical cam, so have probably lost a bit of pressure.
Obviously, I need either stiffer springs or some weight loss from the valvetrain. I thought of putting in the Comp Cams spring locators which have a lip on the inside of the spring base - they are .060" thick. This still leaves a good .060" of clearance before coil bind. I also thought of swapping the stock 3/8" pushrods for the Comp Cams Hi Tech thin-wall chrome-moly pushrods to save a little weight in the valvetrain. They are Comp Cams lightest pushrods. Do these two ideas sound reasonable, or is the pushrod thing a waste of money. Titanium items are frighteningly expensive!
I would like to be able to turn another 300-400 revs, which I think it would do. The hp was still going up steadily by 3-4hp per 100 revs until valve float, with no sign of the curve flattening out at 5500rpm. I think the engine has got an honest 490+hp in it - just bragging rights, of course!!
What do the experts think??
Thanks, Chris

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I have pushed BBC's to about 6,200 and I.M.O.,that is when the game is over.
A lot of it has to do with valve weight,spring weight,retainer weight etc.
I have seen the 454's go 565 hp on pump gas with a hyd. roller and well ported 781 heads fitted with 2.19/1.88 valves.
Yes,I would guess you have 490 hp.

If I were you, I would call Comp Cams and ask their advice. I would consider them the experts. Remember that the stock solid lifter 396-427-454s had a factory redline of 6400 and most would spin to 6800-7000. At least I know my 427s would.

Pat

well the lifters are very heavy .so you do see this at the valve spring .i am not a big fan of bee hive springs . i have seen to many springs fail you have no backup with a dual you do. i would run a dual spring and run the push rods you have now you will never see any thing over the pushrods you have now all your added weigth is the hyd roller lifters.look at comp spring 928-16

Quote:

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Originally Posted by Stu Cool

If I were you, I would call Comp Cams and ask their advice. I would consider them the experts. Remember that the stock solid lifter 396-427-454s had a factory redline of 6400 and most would spin to 6800-7000. At least I know my 427s would.

Pat

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You are comparing apples to orange's here.
There is no way to compare a solid lift cam with a hyd. roller.

My hyd roller in my 427 was done by 5800-6000. We had a combinaton of 2 comp springs on the heads as well.

Thanks, guys.

I'm hoping that with the extra .060" taken from the valve installed-height from using the CC spring locator shims, that I can squeeze another couple of hundred revs out of it.
I have been considering the Crane Sportsman shaft rockers for a while. At $959 (with the $ at 1.6 to the £) they are starting to look more affordable. Anyone have any experience of these? Apparently they use a special polymer-matrix composite bearing instead of needle rollers. Maybe they would help a little bit with the heavy valvetrain inertia?? At the moment I am using roller-tip Comp Cams Magnums (not full-roller Pro Magnums). Another good thing about the shaft rockers is that I think I can get away with the stock valve-covers, because there is no big poly-lock sticking up in the middle like there is with a stud-mounted rocker.

Sorry, I meant $2.06 to the £!
Chris

i think your going at it the wrong way the rockers are not going to help the lifters are to heavy that is it .spending money on the rocker s is no going to help the weight of the lifter you can buy a rev kit for hyd roller cam from isky this help keep the lifter on the cam with out added lbs on the pushrod it puts it on the body of the lifter the shafts may be a better way to go do not think whey will help . you do not need them for this type of build your wasting money put a revkit in it and it will do what you want .there is no need to run the poly-locks just buy new rocker nuts they should work just fine with the rocker you have or buy two set of thick valve cover gaskets and run then two a side on the valve covers i used studs on the stock covers to help keep the gaskets from moving i have run over 600 lift this way with stock covers and poly-locks. if you go tapper pushrods shaft rocker titanium valves this would help and you would still need the rev kit ? lifters are still way heavy**)

Thanks, Pat.

I hadn't thought of a rev-kit - that's a very interesting idea. But, I looked up the Isky site and they don't seem to list one for a BBC. Comp Cams do, but say it's only for solid rollers... It is possible to use a rev kit with hydraulic rollers, is it? Wouldn't they tend to collapse the lifters?
Can you steer me in the direction of an actual part # from any of the manufacturers??

Quote:

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Originally Posted by grifo7

Thanks, Pat.

I hadn't thought of a rev-kit - that's a very interesting idea. But, I looked up the Isky site and they don't seem to list one for a BBC. Comp Cams do, but say it's only for solid rollers... It is possible to use a rev kit with hydraulic rollers, is it? Wouldn't they tend to collapse the lifters?
Can you steer me in the direction of an actual part # from any of the manufacturers??

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you can use one they do this on boats. no it will not collapse the lifter like i said you are putting the added pressure on the lifter body not on the pushrod i will see what i can find my isky book is at my shop

Yes, I get it now, Pat! I'd be very interested if you can turn up a part number for me.Thanks,
Chris

Quote:

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Originally Posted by grifo7

Yes, I get it now, Pat! I'd be very interested if you can turn up a part number for me.Thanks,
Chris

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they have a hat that the spring sets in if your lifters have a full round top to them and not a cut a way lifter or the bar bolt or rivet is not in the way so the hat will set flat. if they have a full round top then the hat will set in to the id of the lifter body so you need to know what lifter s you have if you buy a rev kit you may have to turn the od of step of the hat down to set in the id of your lifter body. so any one can sell you a revkit you just need the right hat to fit in your lifter body .i will look at isky but i need to know who s lifters you have

Pat,

I have Lunati hydraulic lifters, link-bar design, not the pop-up type, #72820.

Chris