Re: 269/275 solid roller install
[Re: B1MAXX]
#3019478
02/27/22 06:41 PM
02/27/22 06:41 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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That's part of my point there is "play " everywhere that real pressures take up. the 0 lash is bad practice, the clearance ramps start the valve action long before is supposed to and timing events are the critical part here.
How is measuring the difference in valve lift at the trouble spot between checking springs and real springs not taking into account the play? The spring force will be loading the entire valvetrain from the roller tip all the way to the camshaft. All the defelecttions from bending the rockers and shafts, to the compressive loads on the pushrods, lifters, and then back to the bending load on the camshaft, accounted for in the lift measurement. In Dave’s case, that’s going to be about 400lbs of force on the valve side of the rocker, and 600+ on the pushrod side. Seems like that should be enough to take up the play. With his parts the deflection might provide enough added clearance for it to work(he’s looking for another .016). I’d take the measurement to find out of it were me. I agree the zero lash thing is a mistake.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019483
02/27/22 06:55 PM
02/27/22 06:55 PM
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Joined: Jan 2003
Posts: 6,150 Melbourne , Australia
LA360
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master
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The lobe lift at TDC is shown in Comp Cams lobe master catalogue, is this the kind of number you are talking about Dwayne?
Alan Jones
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Re: 269/275 solid roller install
[Re: LA360]
#3019490
02/27/22 07:34 PM
02/27/22 07:34 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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i had no idea of that spec or what its for. .139" is what i just measured with cam in at 106.75 Well, according to the lobe specs in the catalog, your old cam should have had .141” lift at TDC, with the cam installed at 106. Which means, in theory(assuming your .139 measurement is correct), the new cam would actually have a tiny amount more clearance........at TDC. Both cams should be moving the lifter about .004/degree at that point in the lift curve. So, if the closest point for v/p clearance is 10ATDC, you’d have another .040” or so tappet rise at that point. All that being said, it would have to be a pretty lazy roller lobe to have 269@.050 and only have .139” tappet lift at TDC, installed at 106. Should be .150” or a bit more. All of which means the loss of all the clearance between the two cams still makes no sense. However....... your .050 numbers of 25/58 come out to 263@.050, not 269. On a very aggressive .430 roller lobe, the difference in lift at TDC, with both cams installed at 106 would be about .010”. What are you getting for open/close points at .020 lift? The lifter bore tool you’re using has the radiused end for the roller cam? What did you use to set/verify the wheel is correct at TDC? The cam card calls out what the cam “should” be. You should be able to have the specs coincide within a degree. If you can’t, either you’re doing it wrong......... or the cam doesn’t match what’s on the card. You can double check yourself by plotting out the old cam.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019498
02/27/22 07:55 PM
02/27/22 07:55 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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The cam card is just numbers on a piece of paper.
The cam measures what it measures.
With the tools on hand to degree the cam, you can make up the cam card.
I trust what I measure.
However, nothing you’ve come up with thus far with all the measuring has explained where the clearance went.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 269/275 solid roller install
[Re: fast68plymouth]
#3019501
02/27/22 08:06 PM
02/27/22 08:06 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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I'm using the pro gear 9 way timing chain set and its a bit confusing with this cam. I set it to straight up dot to dot and get 106.75 with a 108 lobe sep cam. If ya set it at 2R i get 108.25. I don't get it. I’m not understanding the problem. You were at 106.75, then you retarded it “2deg”, and it ended up being 1.5deg(108.25) instead. No biggie.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019511
02/27/22 08:31 PM
02/27/22 08:31 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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Cam is it at 106.75, and the lobe lift at TDC is .139/.140?
Put the old cam back in, do the same test. It should be within a couple of thou, if you can get it close to being in at 106.
Then check the v/p clearance the same way that you have been with the new cam.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019520
02/27/22 09:14 PM
02/27/22 09:14 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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The old cam uses intake lobe number 7072, correct?
Here are the specs from the lobe catalog. You’ll notice the lift at TDC spec is .141, if installed at 106.
The same as what you’re getting with the new cam.
Meaning, the V/P clearance at that point should be the same between the two.
Check the lobe lift between the two at the closest point(10ATDC?), they should still be within a few thou of each other.
As I said earlier....... you have yet to come up with anything that would point to why the new cam has way less clearance.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019640
02/28/22 11:16 AM
02/28/22 11:16 AM
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Joined: Jan 2003
Posts: 4,101 Shelby Twp. Mi
HardcoreB
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Shelby Twp. Mi
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Dave, Sorry for your troubles. What is the cam grind, profile and manufacturer? Who did you get the cam from and why aren't they helping you with these troubles?
Last edited by HardcoreB; 02/28/22 11:18 AM.
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019718
02/28/22 02:33 PM
02/28/22 02:33 PM
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Joined: Jan 2003
Posts: 4,101 Shelby Twp. Mi
HardcoreB
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Shelby Twp. Mi
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The cam is a Bullet solid roller. 269/275@50 on a 108 with .430 lobe lift. I called Bullet last week to speak with Greg about it, but he was out sick and the guy I spoke with could not answer all my questions. Greg is very hard to get ahold of when he’s there. Too busy. If I have time today, I might be able to determine which lobes fit these specs. Assuming there is only one profile peculiar to 269/430 and again one to 275/430. These issues are more an engine builder issue than they are cam manufacturer. So you are the builder and bought the cam directly from them?
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019787
02/28/22 06:22 PM
02/28/22 06:22 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
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I also noticed once i got the head off, the intake valve is not centered in the valve notch and was touching on the right edge of the brow. You might be on to something with that.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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