whats the largest valve lift with j heads and kb piston
#1792143
03/31/15 12:08 AM
03/31/15 12:08 AM
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cheapstreetdustr
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what is a reasonably decent max valve lift I can go on a set of heavily ported and modified J heads with kb hyper 107 pistons and what valve springs to go with it? I have a set of solid roller lifers I may use also. I am looking for someone with technical experience on high lifts with kb 107 pistons and or J heads.
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: whats the largest valve lift with j heads and kb piston
[Re: misfired]
#1792145
04/01/15 01:13 AM
04/01/15 01:13 AM
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cheapstreetdustr
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does anyone have a procedure for measuring clearance in the assembled block.? I have done valve to piston checks at10* btdc and 10* atdc what is the protocol to check. some of the cams im seeing start valve openings as 24*btdc I want to make sure I have clearance. should I pick a cam then use its specs to check clearences in my engine as it is now ...to make sure it wont have valve to piston issues? or check valve to piston contact at say 24* 14* 7* and at tdc.. then do the same after tcd.. and compare it to those same valve events on the cam? for instance find max lift of new cam at crankshaft degrees then open my valves at that point. then open the valve till it hits the piston and measure the difference from max lobe lift..to find the clearance/margin/value.?
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1792146
04/01/15 02:02 AM
04/01/15 02:02 AM
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Posts: 8,022 Tulsa OK
Bad340fish
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I am running about .650 lift with a kb107 and 2.05 valve with an edelbrock head. I don't recall what my p2v clearance was but it wasn't anything to sweat about.
68 Barracuda Formula S 340
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Re: whats the largest valve lift with j heads and kb piston
[Re: Crizila]
#1792149
04/02/15 08:17 PM
04/02/15 08:17 PM
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65signet
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I have a .592/.610 lift solid cam with same pistons, and i am maxed out on valve lift, my piston sits .005 out to the hole. 360 with J heads
1965 Plymouth Barracuda 273 M/SA 1970 Plymouth Duster 360/904 10.60s with J heads
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1998643
01/25/16 09:20 PM
01/25/16 09:20 PM
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cheapstreetdustr
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65 are you happy with the performance of your cam? i have a .040 over 360 with kb 107s . my heads still flow air at .577 with out turbulence .. so i am thinking of going a little bigger just past max flow. and running a solid roller. it has 4600rpm converter and 4.56 gear its pretty heavy at 3310 lbs. but i need or can use more cam...lift at the valve is .488 (Old class rules) car runs great but i know more cam will improve it..based on heads flow...i want to take advantage of it. im ready to pull the trigger...just dont want to buy the wrong cam. or more than one cam at this stage...
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1998655
01/25/16 09:28 PM
01/25/16 09:28 PM
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madscientist
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65 are you happy with the performance of your cam? i have a .040 over 360 with kb 107s . my heads still flow air at .577 with out turbulence .. so i am thinking of going a little bigger just past max flow. and running a solid roller. it has 4600rpm converter and 4.56 gear its pretty heavy at 3310 lbs. but i need or can use more cam...lift at the valve is .488 (Old class rules) car runs great but i know more cam will improve it..based on heads flow...i want to take advantage of it. im ready to pull the trigger...just dont want to buy the wrong cam. or more than one cam at this stage... I don't know why guys think if the head gets turbulent you should stop lifting the valve. Just because it went turbulent at say .550 lift @28 inches don't mean that at 32, or 42 or 60 inches it won't get turbulent even sooner. With a head like you have, it's tough to get much more than .600 NET lift, but if you could do more,I would say do it. If you have to notch the piston for P/V then so be it. If you wanted to mill the stand down and all that you can NET about .700 and still get HP. More lift is almost always better.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1998673
01/25/16 10:04 PM
01/25/16 10:04 PM
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cheapstreetdustr
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just not on this motor.. i have a short block and a set of 245 heads..just not looking to do the hard work with the valve train on that motor right now..
i am not taking this one apart right now..unless it blows up. still got kids to pay for..but its time to get the car back out some this yr. i know looking at my notes...the heads still worked at the .577 lift. it was done at that number..not much more gains after that..but turbulence came in.(i cant read the smudge...)around .620 ..i just want to put in a a little more cam than its has now.. the cam is tiney. the motor was built in 04 so my memory of the flow bench and notes arent good enough...and my page is smudged pretty good fubaring my notes.. i am going mostly off memory.. what i really want to do is avoid piston to valve interference with the roller...i can get pretty aggressive early...thats what iam shooting for. it makes real good numbers from .300" on. just want to pick a cam... been kicking it around in my head..i could fire the car and go run it right now..but since its cold out...i want to pull the cam and stick in something to wake it up. not go too technical...just avoid a mistake. i am looking at a .590 lobe.. but have to have a custom cam ground because i have non conventional rocker ratios
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1998675
01/25/16 10:07 PM
01/25/16 10:07 PM
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Joined: Feb 2004
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cheapstreetdustr
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is scott brown still around..? he did all my last cams...but i have no contact for him anymore?
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1998689
01/25/16 10:32 PM
01/25/16 10:32 PM
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AndyF
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does anyone have a procedure for measuring clearance in the assembled block.? I have done valve to piston checks at10* btdc and 10* atdc what is the protocol to check. some of the cams im seeing start valve openings as 24*btdc I want to make sure I have clearance. should I pick a cam then use its specs to check clearences in my engine as it is now ...to make sure it wont have valve to piston issues? or check valve to piston contact at say 24* 14* 7* and at tdc.. then do the same after tcd.. and compare it to those same valve events on the cam? for instance find max lift of new cam at crankshaft degrees then open my valves at that point. then open the valve till it hits the piston and measure the difference from max lobe lift..to find the clearance/margin/value.? It is fairly simple, you just measure how much space you have at TDC and then use that number when you pick the camshaft. Typically you need to pull the valve springs on #1 cylinder and then use a dial indicator to tell you the space that you have for the valve with the piston at TDC. Look in the lobe spec part of the cam catalog and it will tell you the lobe lift at TDC. Multiply by the rocker arm ratio and that will tell you the valve lift at TDC. Lobe lift at TDC depends a lot on duration rather than lobe lift. A cam with a lot of duration has to get the lifter moving up sooner than a cam with less duration. And rocker arm ratio is critical to this measurement since a high ratio rocker arm gets the valve moving a lot faster than a low ratio arm.
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1998982
01/26/16 01:30 PM
01/26/16 01:30 PM
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Joined: Jun 2003
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MR_P_BODY
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I use the valves that I will run and put tester springs on then use the dial indicator to measure from 10* before to 10* after TDC so I can see if I can move the cam around for the installed.. I do every degree and measure to when it touches the piston and I do both the intake and exhaust... thats just how I do it
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Re: whats the largest valve lift with j heads and kb piston
[Re: dogdays]
#1999062
01/26/16 03:56 PM
01/26/16 03:56 PM
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crackedback
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That seems to me to be a sensible method. If the valve has enough clearance at 10BTDC it MUST have enough clearance at 24BTDC unless the camshaft has a hump in its curve (joke).
Isky used to post VOTDC figures but I wasn't aware the others did that, too.
R. Comp has the info in the master lobe listings. Usually tappet lift at 106 and 110 ICL's IIRC.
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Re: whats the largest valve lift with j heads and kb piston
[Re: cheapstreetdustr]
#1999524
01/27/16 01:06 AM
01/27/16 01:06 AM
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Posts: 7,506 Az
Crizila
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Ran .623 lift. I did some piston notching for additional clearance.
Fastest 300
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Re: whats the largest valve lift with j heads and kb piston
[Re: MR_P_BODY]
#2003149
02/01/16 01:39 AM
02/01/16 01:39 AM
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cheapstreetdustr
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I use the valves that I will run and put tester springs on then use the dial indicator to measure from 10* before to 10* after TDC so I can see if I can move the cam around for the installed.. I do every degree and measure to when it touches the piston and I do both the intake and exhaust... thats just how I do it thats what i did the last time i was diving into this. i have to check my notes.but the 10* btc and atdc is really the answer to my question. if thats adequate to use to pic a cam
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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