'69 427 Bent Push Rod
Thread Starter
Racer
Joined: Apr 2013
Posts: 302
Likes: 16
Installed height is just that....with everything installed. No there is no rotator on the intake. You got some 2.15 installed height number...now subtract the rotator and the shim.
Yes....compress it all of the way and measure.....that is "bind".
This is where a valve spring pressure checker/press comes in handy but we do not have that. We have your installed height number, the cam lift, and soon you will have compressed length.....with these three number you should be able to know if you are coil binding.
The mentioned 1.880 is correct for stock but you seen to be a little more than that.
Jebby
Yes....compress it all of the way and measure.....that is "bind".
This is where a valve spring pressure checker/press comes in handy but we do not have that. We have your installed height number, the cam lift, and soon you will have compressed length.....with these three number you should be able to know if you are coil binding.
The mentioned 1.880 is correct for stock but you seen to be a little more than that.
Jebby
If I subtracted the rotator and shim I would not have enough clearance at .263 as the valve full open is .500
So on the exhaust valve Actual installed height with the rotator and shim is 1.804.... right on the money!
The intake Actual installed height with the .015 shim is 1.901 Not on the money!
Mike
Last edited by Z06CE; Mar 12, 2019 at 10:36 PM.
Thread Starter
Racer
Joined: Apr 2013
Posts: 302
Likes: 16
i agree the Jebby post 116 is probably the best course, but a quick check at TDC will tell if you are statically tight (shaved heads, decked block, thin Head Gaskets), if you got more than 0.250" your probably not hitting the Piston unless the cam has a serious ramp rate (the intake is opening during overlap) or way off cam card install specs. Radial V/P Clearance could still be a problem and I don't think there is an easy way to that with Heads on?
The Umbrella seal value quoted has to do with the retainer to guide clearance and it still could be what bent them (I didn't do any math with the numbers you posted though), I wish you were nearby, i have a nice little setup with an arbor press, pressure gauge etc. that makes this easy (vise and flying springs suck)
The Umbrella seal value quoted has to do with the retainer to guide clearance and it still could be what bent them (I didn't do any math with the numbers you posted though), I wish you were nearby, i have a nice little setup with an arbor press, pressure gauge etc. that makes this easy (vise and flying springs suck)
Mike
Thread Starter
Racer
Joined: Apr 2013
Posts: 302
Likes: 16
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Ive ran .560 intake lift .580 ex lift cams in both chevy closed and open chamber heads. With only .505 lift no way on the planet you had a retainer hit your guide. BBC had more spring installed height then SBC one big reason. That said anyone that would put an unbrella seal on anything should be put before a firing squad. Put a viton seal over your guide when you go back together. I have not read hardly any of these posts. Pull the heads off and get serious about fixing it, from xhecking the valve guides to everything else and throw the valve springs in the trash no mater what they check on pressure.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Pull the heads off let the machinest look at the guides nice thing about factory BBC heads they have press in guides. let him look it all over and set up a new set of springs for you.
Last edited by Little Mouse; Mar 13, 2019 at 01:29 AM.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
Virtually every bbc head has umbrellas on it these days, including OE crate 502 461 hp engines. That is a crap load of bullets and very few engine builders left. Personally I leave exhaust seals out. OP has a bit over .6 clearance with seal, shims and all. Valve guides. Yes they are pressed in. But they are pressed in blank and machined after install. So the valve is not in the canter of the guide. You fix that guide correctly with an insert like any other iron head.
Last edited by derekderek; Mar 13, 2019 at 09:26 AM.
Le Mans Master
Joined: Mar 2004
Posts: 7,502
Likes: 1,509
From: Little Rock AR
JMO - Seems like spending a lot of money and wrenching and buying before any root cause has been found. I would not just measure without a trial fit with one intake valve moving through a valve cycle (witbout a valve spring in place) to see and feel for interfearance. You cant just "measure" for correct valvetrain geometry. FREE fast and easy. Need to look at everything including how they move through the guide plate through a full valve cycle. Not just see if they fit. Something does not fit and the brand new parts might not fit either.
Last edited by stingr69; Mar 13, 2019 at 09:00 AM.
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Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
I have a retainer to guide measurement question. The clearance I measured was .813 for the exhaust. I subtracted .200 for the seal, I have now .613 clearance. Do I subtract the rotator .335 and the shim .015 as well?
If I subtracted the rotator and shim I would not have enough clearance at .263 as the valve full open is .500
So on the exhaust valve Actual installed height with the rotator and shim is 1.804.... right on the money!
The intake Actual installed height with the .015 shim is 1.901 Not on the money!
Mike
If I subtracted the rotator and shim I would not have enough clearance at .263 as the valve full open is .500
So on the exhaust valve Actual installed height with the rotator and shim is 1.804.... right on the money!
The intake Actual installed height with the .015 shim is 1.901 Not on the money!
Mike
Did you get some light tension springs? Get them and perform the procedure from Diamonds website. You need a degree wheel too and a piston stop.
Jebby
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
JMO - Seems like spending a lot of money and wrenching and buying before any root cause has been found. I would not just measure without a trial fit with one intake valve moving through a valve cycle (witbout a valve spring in place) to see and feel for interfearance. You cant just "measure" for correct valvetrain geometry. FREE fast and easy. Need to look at everything including how they move through the guide plate through a full valve cycle. Not just see if they fit. Something does not fit and the brand new parts might not fit either.
what he said!!!!
find two good PRs and put a cylinder back together .... roll motor through by hand a few revs ... as you check coil bind ON MOTOR with a feeler gage & a sharp eye.
Then ... if there is any problem ... take heads to shop
Thread Starter
Racer
Joined: Apr 2013
Posts: 302
Likes: 16
Ok some new info.
Did some measurements.... on the exhaust valve
I only have .020 clearance for coil bind .
Gong to verify again tomorrow with the intake and exhaust.
Spring Intake and exhaust bind is 1.280
At .500 is 1.260... .020 clearance... Not good
Did some measurements.... on the exhaust valve
I only have .020 clearance for coil bind .
Gong to verify again tomorrow with the intake and exhaust.
Spring Intake and exhaust bind is 1.280
At .500 is 1.260... .020 clearance... Not good
Burning Brakes
Joined: Jul 2016
Posts: 767
Likes: 74
From: Blaine MN
Good thing I didn't have any real money on v/p clearance. It sounds like you have the culprit, easy fix compared to v/p issues. I think you should still follow Jebby advice and degree it. Cheap insurance and then you know where it's at for sure (just for the timing marks alone).
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
? OR ... is that 0.020" a SUM TOTAL of all measurements between any/all gaps between all coils of that particular spring?
* pics of Both I & E springs at Max Lift ON MOTOR with feeler gage inserted might assist.
* recall you were to perform leakdown across all eight ... result?
* recall you were to borescope all eight ... result?
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Exhaust valve Actual installed height with the rotator and shim is 1.804.... right on the money!
The intake Actual installed height with the .015 shim is 1.901
I'm just tying to figure out what is being said. First of all they are not rotators. Rotators actually cause the valve to rotate. Retainers, retain the springs. 1.804 is not right on the money if you have springs that actually coil bind at 1.280 inches. Shims are used to set the installed height and what ever closed pressure. You can buy +.050 higher retainers and run next to nothing for a shim to alleviate the coil bind problem on your next set of springs. For BBC heads I usually set them up with about 2.00 installed heights and H-flat lifters in the 140# intake and 135# exhaust closed pressures.
These are my AFR SBC heads and I used .200 longer valve stems to be able to have 2.05 installed height when using @.700 lifts. My springs are on the last page. 26115 about 228# closed and about 600# open
go to the fourth page and see the spring# 924, 925, or 911? You would set them up for 1.850 installed height and you would get 129, 131, or 141 closed pressures. Your mild cam the 924's might be a good bet. or 924 on the exhaust and 911 on your intake. coil bind is about 1.200, so they are good to go with mild .500 lifts
http://www.compcams.com/Base/pdf/ValveSpringChart.pdf
https://www.summitracing.com/nv/part...5-16/overview/
The intake Actual installed height with the .015 shim is 1.901
I'm just tying to figure out what is being said. First of all they are not rotators. Rotators actually cause the valve to rotate. Retainers, retain the springs. 1.804 is not right on the money if you have springs that actually coil bind at 1.280 inches. Shims are used to set the installed height and what ever closed pressure. You can buy +.050 higher retainers and run next to nothing for a shim to alleviate the coil bind problem on your next set of springs. For BBC heads I usually set them up with about 2.00 installed heights and H-flat lifters in the 140# intake and 135# exhaust closed pressures.
These are my AFR SBC heads and I used .200 longer valve stems to be able to have 2.05 installed height when using @.700 lifts. My springs are on the last page. 26115 about 228# closed and about 600# open
go to the fourth page and see the spring# 924, 925, or 911? You would set them up for 1.850 installed height and you would get 129, 131, or 141 closed pressures. Your mild cam the 924's might be a good bet. or 924 on the exhaust and 911 on your intake. coil bind is about 1.200, so they are good to go with mild .500 lifts
http://www.compcams.com/Base/pdf/ValveSpringChart.pdf
https://www.summitracing.com/nv/part...5-16/overview/
Last edited by gkull; Mar 14, 2019 at 12:26 PM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Exhaust valve Actual installed height with the rotator and shim is 1.804.... right on the money!
The intake Actual installed height with the .015 shim is 1.901
I'm just tying to figure out what is being said. First of all they are not rotators. Rotators actually cause the valve to rotate. Retainers, retain the springs. 1.804 is not right on the money if you have springs that actually coil bind at 1.280 inches. Shims are used to set the installed height and what ever closed pressure. You can buy +.050 higher retainers and run next to nothing for a shim to alleviate the coil bind problem on your next set of springs. For BBC heads I usually set them up with about 2.00 installed heights and H-flat lifters in the 140# intake and 135# exhaust closed pressures.
These are my AFR SBC heads and I used .200 longer valve stems to be able to have 2.05 installed height when using @.700 lifts. My springs are on the last page. 26115 about 228# closed and about 600# open
go to the fourth page and see the spring# 924, 925, or 911? You would set them up for 1.850 installed height and you would get 129, 131, or 141 closed pressures. Your mild cam the 924's might be a good bet. or 924 on the exhaust and 911 on your intake. coil bind is about 1.200, so they are good to go with mild .500 lifts
http://www.compcams.com/Base/pdf/ValveSpringChart.pdf
https://www.summitracing.com/nv/part...5-16/overview/
The intake Actual installed height with the .015 shim is 1.901
I'm just tying to figure out what is being said. First of all they are not rotators. Rotators actually cause the valve to rotate. Retainers, retain the springs. 1.804 is not right on the money if you have springs that actually coil bind at 1.280 inches. Shims are used to set the installed height and what ever closed pressure. You can buy +.050 higher retainers and run next to nothing for a shim to alleviate the coil bind problem on your next set of springs. For BBC heads I usually set them up with about 2.00 installed heights and H-flat lifters in the 140# intake and 135# exhaust closed pressures.
These are my AFR SBC heads and I used .200 longer valve stems to be able to have 2.05 installed height when using @.700 lifts. My springs are on the last page. 26115 about 228# closed and about 600# open
go to the fourth page and see the spring# 924, 925, or 911? You would set them up for 1.850 installed height and you would get 129, 131, or 141 closed pressures. Your mild cam the 924's might be a good bet. or 924 on the exhaust and 911 on your intake. coil bind is about 1.200, so they are good to go with mild .500 lifts
http://www.compcams.com/Base/pdf/ValveSpringChart.pdf
https://www.summitracing.com/nv/part...5-16/overview/
Only stock heads have the rotators.....
The 924 is a very common "belly button" spring for stock heads.....I used to stock them at the Speed Shop.....
Jebby
Last edited by Jebbysan; Mar 14, 2019 at 12:34 PM.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
https://www.chevydiy.com/wp-content/...Image_0004.jpg
" If exhaust valve rotators are still present on a head it’s a pretty good clue that it was used on a truck engine. They are easily identified; they look like little sealed roller bearings approximately .25 inch thick underneath each exhaust valvespring. "
source
https://www.chevydiy.com/how-to-sour...ylinder-heads/
" If exhaust valve rotators are still present on a head it’s a pretty good clue that it was used on a truck engine. They are easily identified; they look like little sealed roller bearings approximately .25 inch thick underneath each exhaust valvespring. "
source
https://www.chevydiy.com/how-to-sour...ylinder-heads/
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
https://www.chevydiy.com/wp-content/...Image_0004.jpg
" If exhaust valve rotators are still present on a head it’s a pretty good clue that it was used on a truck engine. They are easily identified; they look like little sealed roller bearings approximately .25 inch thick underneath each exhaust valvespring. "
source
https://www.chevydiy.com/how-to-sour...ylinder-heads/
" If exhaust valve rotators are still present on a head it’s a pretty good clue that it was used on a truck engine. They are easily identified; they look like little sealed roller bearings approximately .25 inch thick underneath each exhaust valvespring. "
source
https://www.chevydiy.com/how-to-sour...ylinder-heads/
I think it was more of a hardened valve seat thing than a truck thing.......why you rotate it is beyond me anyway......
Jebby
Last edited by Jebbysan; Mar 14, 2019 at 12:52 PM.