7.550 PR length?
7.550 PR length? Is there anyway that could be right? My calculations say it is right. LS7 lifters, YT non-adj. shimmed up .095" to get good wipe pattern, .040" head gasket (wasn't compressed but we are talking a few thousandths there.... head bolts were snugged), .024" mill on heads . Checker showed between 7.450-7.500
7.450 had a touch of tick. 7.500 was too tight. Add .050-.080" for preload and I'm around 7.550" LSL lobes maybe on a smaller base circle?
7.450 had a touch of tick. 7.500 was too tight. Add .050-.080" for preload and I'm around 7.550" LSL lobes maybe on a smaller base circle?
It all depends on the cams base circle, but that seems pretty extreme. I put in the 7.50's that came with my TFS heads and they were so long that the motor couldn't even build compression. I sounded like i was turning it over with no spark plugs
Well I guess it was 13 turns. I was just adding .050" per turn. I ended up with .650" worth of spinning it out to get the light tick. So 13 X .050" is .650" yes. And 6.800 + .650 = 7.450 before preload.
Also the lifters were only in the trays about 1/8" at best when on the base circle of the cam which didn't make me very comfortable.
Also the lifters were only in the trays about 1/8" at best when on the base circle of the cam which didn't make me very comfortable.
Sounds correct. 0.095" shims results in the need for 0.151" longer pushrod. If you assume 7.400 as a starting point, that puts you right at 7.550".
That is a fairly long pushrod, I would strongly suggest you see if an 11/32" diameter pushrod will fit and then contact Terry Manton as he has these and will make to the length you need. Other option is if the heads are on yet, open the pushrod holes slightly for 3/8" pushrods. Pushrod flex is a major issue with these motors that most ignore or are unaware of.
I have the AFR's and found that a 0.125" shim is required. Do you have a photo of the wipe pattern? Mine was close at 0.095 but the 0.125" made it perfect. Difference for me is that the Morel lifters are taller and require less preload so my pushrod should come in at around 7.500".
That is a fairly long pushrod, I would strongly suggest you see if an 11/32" diameter pushrod will fit and then contact Terry Manton as he has these and will make to the length you need. Other option is if the heads are on yet, open the pushrod holes slightly for 3/8" pushrods. Pushrod flex is a major issue with these motors that most ignore or are unaware of.
I have the AFR's and found that a 0.125" shim is required. Do you have a photo of the wipe pattern? Mine was close at 0.095 but the 0.125" made it perfect. Difference for me is that the Morel lifters are taller and require less preload so my pushrod should come in at around 7.500".
No my dumbass didn't take a picture. I have been taking pictures of all the critical steps and forgot to take a picture of that and the heads are already back off now. 
I was pretty happy with .095" I just took a pair of shims off one of the other rocker pedestals and liked it. And if I go more shims, I will add more length to the PR..... and more weight to the valvetrain assembly 
Should I go re-assemble again, vette, and recheck with more shims? I want to get the right pushrods the first time. And would you be comfortable with less than 1/8" of the lifter being in the tray while being on the base circle? I know that it is only keeping the lifter from spinning, but that's not much hanging on there! I know, I know... the morels but just more money
I was pretty happy with .095" I just took a pair of shims off one of the other rocker pedestals and liked it. And if I go more shims, I will add more length to the PR..... and more weight to the valvetrain assembly Should I go re-assemble again, vette, and recheck with more shims? I want to get the right pushrods the first time. And would you be comfortable with less than 1/8" of the lifter being in the tray while being on the base circle? I know that it is only keeping the lifter from spinning, but that's not much hanging on there! I know, I know... the morels but just more money
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No my dumbass didn't take a picture. I have been taking pictures of all the critical steps and forgot to take a picture of that and the heads are already back off now. I was pretty happy with .095" I just took a pair of shims off one of the other rocker pedestals and liked it. And if I go more shims, I will add more length to the PR..... and more weight to the valvetrain assembly
Should I go re-assemble again, vette, and recheck with more shims? I want to get the right pushrods the first time. And would you be comfortable with less than 1/8" of the lifter being in the tray while being on the base circle? I know that it is only keeping the lifter from spinning, but that's not much hanging on there! I know, I know... the morels but just more money
I was pretty happy with .095" I just took a pair of shims off one of the other rocker pedestals and liked it. And if I go more shims, I will add more length to the PR..... and more weight to the valvetrain assembly Should I go re-assemble again, vette, and recheck with more shims? I want to get the right pushrods the first time. And would you be comfortable with less than 1/8" of the lifter being in the tray while being on the base circle? I know that it is only keeping the lifter from spinning, but that's not much hanging on there! I know, I know... the morels but just more money
You want to use a single shim, not stacked. Use the shims you have (or even different thickness washers) to figure out exactly what you need for thickness and then buy a single shim (McMaster-Carr has something that will work).
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Verdad Gallardo The problem is the angle that the pushrod goes through as it opens and closes the valves, the larger pushrods will contact. Don't worry about added weight on the pushrod side of the rocker.
You can get shims for the valve covers so you don't have to replace them.
JEG's has them.
I had to use 1/2" ones to get enough clearance for my rockers even after I ground out every boss and baffle.
JEG's has them.
I had to use 1/2" ones to get enough clearance for my rockers even after I ground out every boss and baffle.
And yes, I'm using the checker springsI called Terry Manton's shop. Quite the place... they will make any length pushrod, any diameter, any grade you want. However, they were going to be hard pressed to get them to me in time for next weekend. I'm kind of on a time line to get this thing done. So I called Comp Cams and they had a 5/16" 7.550" .105" wall hardened pushrod on their shelf. I told the tech I had LSL lobes and he didn't seem to think I'd have a problem so I ordered them.
Oh, on the lifter tray deal, I wasn't trying to relate it to the PR issue. Just that they weren't in the trays very far at all when on the base circle.
I will play with the wipe pattern again and see what I come up with. I'll probably keep it right around .100" range beings I ordered the length already. I will have a little play cause I am a touch on the long side with the PR. We have a very nice machine shop at work and I'm on nights the next two weeks. I'll see if we can't make some shims the correct thickness so I can avoid stacking washers
Thanks for your great help!
That length is not out of the realm of what I've seen needed with shimmed YT rockers and small base circle cams.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Wipe pattern with .095" shim. The line is a little wide as I was checking P/V clearance at the same time so I was using up a lot of stroke on the valves........ or simulating float
Exhaust valve didn't leave quite the impression, but it still looks centered to me
Exhaust valve didn't leave quite the impression, but it still looks centered to me
