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Re: 269/275 solid roller install
[Re: lancer493]
#3019158
02/26/22 06:02 PM
02/26/22 06:02 PM
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Joined: May 2011
Posts: 4,489
northern,Ohio,USA
Clanton
master
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master
Joined: May 2011
Posts: 4,489
northern,Ohio,USA
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I agree with B1 MAX. You really should do a careful clay check with 1 cylinder outfitted with the actual valve springs and valve gear being used or considered. The system of checking with a dial indicater only checks the depths of the valve pockets. It doesn't check the valve margin's radial clearance in the valve pocket unless it is the first point of contact when checking the depth. You could have only .002" radial clearance and never know it til you fire it up and that ain't gonna be good. When I had the pistons made by Diamond I told them they were for Victor heads, they said it mattered as they were somewhat different than others. I ended up with plenty of clearance there when I assembled. Careful clay measuring is quite accurate contrary to what some believe.It is the only way I know of to see actual verifiable minimum radial clearance. I'm sure that statement will draw a lot of fire, but I'm speaking of a proceedure we could all do in our driveway or garage and feel safe with our findings. Bill I used a long center punch and put it in the v guide and marked my piston and also did a clay check for radial clearence.
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Re: 269/275 solid roller install
[Re: lancer493]
#3019178
02/26/22 07:09 PM
02/26/22 07:09 PM
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Joined: Jan 2007
Posts: 8,042
Mt Morris Michigan
mopar dave
OP
master
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OP
master
Joined: Jan 2007
Posts: 8,042
Mt Morris Michigan
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Last time the heads were off i measure with clay and had .050 radial from what i remember. The valve is a 2.200 and the piston notch is good for up to 2.30 valve. Now that the head needs to come off, it will be way easier measuring things including v/p using clay.
Last edited by mopar dave; 02/26/22 07:09 PM.
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019235
02/26/22 10:01 PM
02/26/22 10:01 PM
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Joined: Oct 2005
Posts: 271
Anchorage, Alaska
metallicareload
enthusiast
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enthusiast
Joined: Oct 2005
Posts: 271
Anchorage, Alaska
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Dwayne, with the extension on my dial indicator at the same angle the pushrod runs i measure.400" lobe lift. H8 to interrupt, but during overlap (cylinder 6 firing)?
440, 4-Speed, 3.54
1968, when Dinosaurs ruled the Earth
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Re: 269/275 solid roller install
[Re: mopar dave]
#3019347
02/27/22 11:36 AM
02/27/22 11:36 AM
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Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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Dwayne, with the extension on my dial indicator at the same angle the pushrod runs i measure.400" lobe lift. You aren’t grasping what I’m asking for. The lifter rise from the base circle when the piston is at TDC during overlap. It will be something like .160”.
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]
#3019358
02/27/22 11:57 AM
02/27/22 11:57 AM
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Joined: May 2011
Posts: 4,489
northern,Ohio,USA
Clanton
master
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master
Joined: May 2011
Posts: 4,489
northern,Ohio,USA
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Dwayne, with the extension on my dial indicator at the same angle the pushrod runs i measure.400" lobe lift. You aren’t grasping what I’m asking for. The lifter rise from the base circle when the piston is at TDC during overlap. It will be something like .160”. I have been thinking that the cam card would be very helpful during his 2 topics on this along with piston to deck,valve reliefe depth.
Last edited by Clanton; 02/27/22 11:59 AM.
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Re: 269/275 solid roller install
[Re: Clanton]
#3019366
02/27/22 12:14 PM
02/27/22 12:14 PM
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Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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The info I’m asking for isn’t on the cam card.
My primary reason for asking are because of Dave’s comments about the measurements he’s taken not agreeing with the cam card.
That, and the fact that the new cam “should” only have about .020” more tappet lift when the V/P clearance is closest.
If he actually had .118” clearance before, the new cam should fit no problem.
So, either it didn’t have as much clearance as he thought it did with the old cam, or the new cam is somehow showing more lift in that part of the lift curve than it “should”.
The first thing I would have done when the new cam had “0” V/P clearance........would have been to slide the old cam back in and verify I had the clearance I thought I had.
Prior to even checking the clearance, I would have plotted the new cam out to verify it matched the card.
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]
#3019383
02/27/22 12:46 PM
02/27/22 12:46 PM
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Joined: May 2011
Posts: 4,489
northern,Ohio,USA
Clanton
master
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master
Joined: May 2011
Posts: 4,489
northern,Ohio,USA
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The info I’m asking for isn’t on the cam card.
My primary reason for asking are because of Dave’s comments about the measurements he’s taken not agreeing with the cam card.
That, and the fact that the new cam “should” only have about .020” more tappet lift when the V/P clearance is closest.
If he actually had .118” clearance before, the new cam should fit no problem.
So, either it didn’t have as much clearance as he thought it did with the old cam, or the new cam is somehow showing more lift in that part of the lift curve than it “should”.
The first thing I would have done when the new cam had “0” V/P clearance........would have been to slide the old cam back in and verify I had the clearance I thought I had.
Prior to even checking the clearance, I would have plotted the new cam out to verify it matched the card. I have struggled with that battle in the past not wanting to go backwards just forward until you give into going back like you said.
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Re: 269/275 solid roller install
[Re: Clanton]
#3019392
02/27/22 01:05 PM
02/27/22 01:05 PM
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Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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It’s not going backward, it’s just a verification....... especially since it sounds like the old .118” clearance figure was obtained using a different method than he’s using this time around.
Slipping the old cam back in and checking the clearances wouldn’t take(me) long at all.
(Certainly less time than has been invested in this thread)
One of Comps most aggressive 269@.050 .430 roller lobes only has .021” more lobe lift at TDC than Dave’s old SFT cam, with both installed at 106.
With a net RR of 1.65, he should only have lost about .035” clearance.
Instead he’s coming up with over double that difference(.118(old) - .044(new)= .073)
It doesn’t add up....... simple as that.
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: B1MAXX]
#3019399
02/27/22 01:17 PM
02/27/22 01:17 PM
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Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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If he checked the old cam with clay as he says, then this time with checking springs.... there you go.
.118 with clay
.064 + .030 = .094 with springs accounting for clay method. Intake clearance is said to be .044”. I doubt there is .030” deflection at the point where the clearance issue is. At the very least, I would verify it with an indicator. Measured lift at point where V/P clearance is closest with checking spring vs measured lift at that same point with full spring pressure. However much less lift is observed with the big springs(at that point), add that you the .044” clearance figure. At 10* ATDC the tappet lift should be close to .200”. With a 1.65 rocker that’s .330” lift. Take out the .020 lash....... .310 at the valve. A PAC 1243 is 550lb/in...... .550 x .310 = 170.5 + 240 on the seat is 410lbs at that point. Does that equate to .030 deflection at that point with Dave’s parts? Only one way to know for sure. And...... you’d need the correct “real” pushrods(not a checking pushrod) to get an accurate deflection measurement. When I tested some 1.6HS rockers, the deflection was only .018” at full lift with 700lbs open force.
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]
#3019401
02/27/22 01:21 PM
02/27/22 01:21 PM
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Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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The bottom line is this, when he had zero clearance initially(even adding in the .020” lash).........if the cam position was verified as correct....... that cam isn’t likely going to fit without modifying something.
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: B1MAXX]
#3019443
02/27/22 03:47 PM
02/27/22 03:47 PM
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Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,504
So. Burlington, Vt.
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I believe the “0” clearance was done with the cam in at 104, and zero lash....... and I think the .044 is with the cam at 106 and lash.
What I meant was, when it was checked with zero lash and the clearance was zero...... if you had the lash set of .020, you’d have had .020 clearance.
Still far enough from something preferred that it’s likely going to be a marginal fit.
I’ll test the theory about how the spring tension gives you a little extra clearance by pulling the valve into the head harder.
I’ll measure the valve drop between no spring, and then with a spring that’s about 200 on the seat.
Of course, any elasticity there might be over the length of the valve when it’s closed will be removed once the valve comes off the seat.
At that point, the load on the valve is between the tip and the keeper groove.
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]
#3019457
02/27/22 05:36 PM
02/27/22 05:36 PM
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Joined: May 2005
Posts: 1,993
Apollo, PA.
B1MAXX
top fuel
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top fuel
Joined: May 2005
Posts: 1,993
Apollo, PA.
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I believe the “0” clearance was done with the cam in at 104, and zero lash....... and I think the .044 is with the cam at 106 and lash.
What I meant was, when it was checked with zero lash and the clearance was zero...... if you had the lash set of .020, you’d have had .020 clearance.
Still far enough from something preferred that it’s likely going to be a marginal fit.
I’ll test the theory about how the spring tension gives you a little extra clearance by pulling the valve into the head harder.
I’ll measure the valve drop between no spring, and then with a spring that’s about 200 on the seat.
Of course, any elasticity there might be over the length of the valve when it’s closed will be removed once the valve comes off the seat.
At that point, the load on the valve is between the tip and the keeper groove.
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.
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