Major Issue's Please Help!
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
billa...
Therein lies the problem. The "twist it with your fingers until you just detect drag" includes an element of feel which is very subtle, at best. And if you haven't done that procedure before, many only detect a different "feel" when the piston starts to bind up. Thus, folks aren't setting the valves correctly. You can verbally instruct and re-instruct till you're blue in the face with limited success. With the 'twist/spin the pushrod' method, some will get it and many will not. Once they are shown that difference [visually and by feel] it becomes apparent to them...but that procedure cannot be effectively communicated in a verbal manner only.
Therein lies the problem. The "twist it with your fingers until you just detect drag" includes an element of feel which is very subtle, at best. And if you haven't done that procedure before, many only detect a different "feel" when the piston starts to bind up. Thus, folks aren't setting the valves correctly. You can verbally instruct and re-instruct till you're blue in the face with limited success. With the 'twist/spin the pushrod' method, some will get it and many will not. Once they are shown that difference [visually and by feel] it becomes apparent to them...but that procedure cannot be effectively communicated in a verbal manner only.
Any volunteers in Seattle?
We're in agreement, I think, on the importance of correctly finding zero lash - and whatever works for someone, works.
Last edited by billla; Jan 6, 2010 at 09:56 AM.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
To the OP. Did you install new lifters with the new cam? Did you lubricate everything liberally with a good Moly assembly lube? Did you make sure the lifters spun freely in the bores? Did you use a High Zinc break in oil? Did you prime the engine with a proper priming tool and make sure you had good oil flow to the top of the engine before starting? Did you follow the new cam break in procedure to a tee? Even if you did all of the above you could easily have a wiped lobe or bent a pushrod from too tight of initial valve lash adjustment. Did you set up your valvetrain geometry correctly? Did you use a pushrod length checker and get a centered pattern at your valve tip to rocker tip interface? This won't caure your backfire but will cause issues with accelerated guide wear and possible binding if it is real bad. If you didn't do this it is cheap and easy and geometry should be checked anytime any change is made in the valvetrain. You made numerous changes. Missing anything above can cause serious issues and or premature or immediate death of the valvetrain.
Last edited by 63mako; Jan 6, 2010 at 10:55 AM.
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
To the OP. Did you install new lifters with the new cam? Did you lubricate everything liberally with a good Moly assembly lube? Did you make sure the lifters spun freely in the bores? Did you use a High Zinc break in oil? Did you prime the engine with a proper priming tool and make sure you had good oil flow to the top of the engine before starting? Did you follow the new cam break in procedure to a tee? Even if you did all of the above you could easily have a wiped lobe or bent a pushrod from too tight of initial valve lash adjustment. Did you set up your valvetrain geometry correctly? Did you use a pushrod length checker and get a centered pattern at your valve tip to rocker tip interface? This won't caure your backfire but will cause issues with accelerated guide wear and possible binding if it is real bad. If you didn't do this it is cheap and easy and geometry should be checked anytime any change is made in the valvetrain. You made numerous changes. Missing anything above can cause serious issues and or premature or immediate death of the valvetrain.
with everything you said, but I think we're going to scare the hell out of the OP... 
Cruising
Joined: Jan 2010
Posts: 11
Likes: 0
From: Friendswood Texas
Heads
http://www.summitracing.com/parts/SUM-162111/
Head Gaskets
http://www.summitracing.com/parts/FPP-1003/
Carb
http://www.summitracing.com/parts/HLY-0-80457S/
Intake Gasket
http://www.summitracing.com/parts/FPP-1256/?rtype=10
Used ARP bolts for everything, comp cam and comp hydraulic lifters.
Thanks again for all the help I really feel as if I am getting close!
Justin
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Haha!!! Yes I did do all of the above I am pretty much a stickler at following the instructions to the T. I checked pushrod length again to make sure it lined up in the middle and it is right there. Yes I did prime and made sure to use break in oil as well. At this point I am pretty sure it has to do with the accelerator. I messed with the spring and already noticed a slight change (Backfire almost gone just a small pop) So I am going to run out today to a local speed shop and get a whole kit with different cams and pump shots.
Heads
http://www.summitracing.com/parts/SUM-162111/
Head Gaskets
http://www.summitracing.com/parts/FPP-1003/
Carb
http://www.summitracing.com/parts/HLY-0-80457S/
Intake Gasket
http://www.summitracing.com/parts/FPP-1256/?rtype=10
Used ARP bolts for everything, comp cam and comp hydraulic lifters.
Thanks again for all the help I really feel as if I am getting close!
Justin
Heads
http://www.summitracing.com/parts/SUM-162111/
Head Gaskets
http://www.summitracing.com/parts/FPP-1003/
Carb
http://www.summitracing.com/parts/HLY-0-80457S/
Intake Gasket
http://www.summitracing.com/parts/FPP-1256/?rtype=10
Used ARP bolts for everything, comp cam and comp hydraulic lifters.
Thanks again for all the help I really feel as if I am getting close!
Justin
Barry's timing links in the sticky at the top of the C3 tech & perf. page also have links to some of Lars valvetrain adjustment and carb troubleshooting info. Good luck!
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
On many occasions I had engines come in on warrenty because someone Adjusted the valves after we had them set.
When I was rebuilding engines I had to quickly adjust the valves, then spin the engine on a test/breakin machine. I had a hard time with the spinning method so I went with the jiggle up and down until I couldn't feel or see the pushrod move with light pressure. Then I'd give it a 1/2 turn on stock cams and a 1/4 turn with performance cams. Then move on to the next cylinder on the compression stroke. Almost never did a valve need to be readjusted. (Tip, Always make sure the lifter is pumped up all the way)
Yes... I know. You may find a pony if you do it just right but I would rather have a valve a little on the loose side (not tapping) than have it too tight.
When I was rebuilding engines I had to quickly adjust the valves, then spin the engine on a test/breakin machine. I had a hard time with the spinning method so I went with the jiggle up and down until I couldn't feel or see the pushrod move with light pressure. Then I'd give it a 1/2 turn on stock cams and a 1/4 turn with performance cams. Then move on to the next cylinder on the compression stroke. Almost never did a valve need to be readjusted. (Tip, Always make sure the lifter is pumped up all the way)Yes... I know. You may find a pony if you do it just right but I would rather have a valve a little on the loose side (not tapping) than have it too tight.
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Pretty much of the basics have been covered, but I would like to throw this out....
- Pull #1 plug and crank over the engine until you feel compression. Line up the timing mark on the damper exactly on TDC compression stroke with zero 0 degrees.
- Pull the cap and verify the rotor is pointing at #1 tower on the distributor, not 1/2 way between. This can happen when you pull the distributor and drop it in close. This will radically effect your timing, it wil run but not right.
- Get you carb set to factory or use a base carb jettings and float level.
- Hook up a vacuum gauge to manifold vacuum and start it up. Set the timing to factory spec of say 8-10 degrees. Forget the 32, 34, 36 for now.
- Vacuum should be pretty steady and pulling between 17-20", unless the cam has a long duration.
- If the vacuum is steady at say 20 then drops 4-5 points then back up, yes you have a stuck valve or partially open one and maybe adjustment is needed.
Send me your email address to jamesparks17@yahoo.com and I'll send you info on troubleshooting with a vacuum gauge. Good luck.
- Pull #1 plug and crank over the engine until you feel compression. Line up the timing mark on the damper exactly on TDC compression stroke with zero 0 degrees.
- Pull the cap and verify the rotor is pointing at #1 tower on the distributor, not 1/2 way between. This can happen when you pull the distributor and drop it in close. This will radically effect your timing, it wil run but not right.
- Get you carb set to factory or use a base carb jettings and float level.
- Hook up a vacuum gauge to manifold vacuum and start it up. Set the timing to factory spec of say 8-10 degrees. Forget the 32, 34, 36 for now.
- Vacuum should be pretty steady and pulling between 17-20", unless the cam has a long duration.
- If the vacuum is steady at say 20 then drops 4-5 points then back up, yes you have a stuck valve or partially open one and maybe adjustment is needed.
Send me your email address to jamesparks17@yahoo.com and I'll send you info on troubleshooting with a vacuum gauge. Good luck.
Racer
Joined: Nov 2009
Posts: 289
Likes: 0
From: Franksville Wisconsin
I have to wonder if we have a misunderstanding here of the "spin" method - there's no spinning and releasing. Could be the core of the "Holy War"...because I can't see how "spinning" a pushrod would work for anything.
Grasp the pushrod between thumb and forefinger. Roll slowly back and forth between your fingers while slowly and consistently tightening the rocker. The first time you feel ANY drag is zero lash. The pushrod never "spins".
Not restarting this whole acerbic debate - just noting that we may have a misunderstanding of methods that's causing the opposition...which if it is as you're describing it I completely agree that ain't gonna work for anyone.
Grasp the pushrod between thumb and forefinger. Roll slowly back and forth between your fingers while slowly and consistently tightening the rocker. The first time you feel ANY drag is zero lash. The pushrod never "spins".
Not restarting this whole acerbic debate - just noting that we may have a misunderstanding of methods that's causing the opposition...which if it is as you're describing it I completely agree that ain't gonna work for anyone.
Once the lifter self adjusts the pushrods may spin slightly. The lifter must spin while running or it will fail.Thats why breakin instructions say do not idle and the fast speed method to make sure lifters rotate and get good oil supply.
Last edited by WhiteC3; Jan 7, 2010 at 11:17 AM.
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Cruising
Joined: Jan 2010
Posts: 11
Likes: 0
From: Friendswood Texas
Pretty much of the basics have been covered, but I would like to throw this out....
- Pull #1 plug and crank over the engine until you feel compression. Line up the timing mark on the damper exactly on TDC compression stroke with zero 0 degrees.
- Pull the cap and verify the rotor is pointing at #1 tower on the distributor, not 1/2 way between. This can happen when you pull the distributor and drop it in close. This will radically effect your timing, it wil run but not right.
- Get you carb set to factory or use a base carb jettings and float level.
- Hook up a vacuum gauge to manifold vacuum and start it up. Set the timing to factory spec of say 8-10 degrees. Forget the 32, 34, 36 for now.
- Vacuum should be pretty steady and pulling between 17-20", unless the cam has a long duration.
- If the vacuum is steady at say 20 then drops 4-5 points then back up, yes you have a stuck valve or partially open one and maybe adjustment is needed.
Send me your email address to jamesparks17@yahoo.com and I'll send you info on troubleshooting with a vacuum gauge. Good luck.
- Pull #1 plug and crank over the engine until you feel compression. Line up the timing mark on the damper exactly on TDC compression stroke with zero 0 degrees.
- Pull the cap and verify the rotor is pointing at #1 tower on the distributor, not 1/2 way between. This can happen when you pull the distributor and drop it in close. This will radically effect your timing, it wil run but not right.
- Get you carb set to factory or use a base carb jettings and float level.
- Hook up a vacuum gauge to manifold vacuum and start it up. Set the timing to factory spec of say 8-10 degrees. Forget the 32, 34, 36 for now.
- Vacuum should be pretty steady and pulling between 17-20", unless the cam has a long duration.
- If the vacuum is steady at say 20 then drops 4-5 points then back up, yes you have a stuck valve or partially open one and maybe adjustment is needed.
Send me your email address to jamesparks17@yahoo.com and I'll send you info on troubleshooting with a vacuum gauge. Good luck.
Justin
Race Director
Joined: Aug 2004
Posts: 10,628
Likes: 132
From: Duvall, WA
- Pull #1 plug and crank over the engine until you feel compression. Line up the timing mark on the damper exactly on TDC compression stroke with zero 0 degrees.
- Pull the cap and verify the rotor is pointing at #1 tower on the distributor, not 1/2 way between. This can happen when you pull the distributor and drop it in close. This will radically effect your timing, it wil run but not right.
- Pull the cap and verify the rotor is pointing at #1 tower on the distributor, not 1/2 way between. This can happen when you pull the distributor and drop it in close. This will radically effect your timing, it wil run but not right.
I disagree with this too. It's all about total timing. Get the 36° and don't worry about where your initial timing is.
Cruising
Joined: Jan 2010
Posts: 11
Likes: 0
From: Friendswood Texas
Ok update.
Got the car running and semi smooth to boot! Got timing exactly at 36 and she sounds great! Downside is I have to track down a vacuum leak now... I was doing all the main tuning with every vacuum port plugged and when I rev it no backfire at all! Hook up all the vacuum lines and BOOM! I have tracked it down and have a fair idea where to start with it. I think I am just going to yank all the lines I have yet to replace and do it all in 1 go, then I can see if it is the canister or not. So far so good!
Another question though, when setting the vacuum idle on an automatic I know you should do it in drive with someone mashing down on the break. I did that and the vacuum was only reading around 8, seems very low. Any thoughts on this or why?
Got the car running and semi smooth to boot! Got timing exactly at 36 and she sounds great! Downside is I have to track down a vacuum leak now... I was doing all the main tuning with every vacuum port plugged and when I rev it no backfire at all! Hook up all the vacuum lines and BOOM! I have tracked it down and have a fair idea where to start with it. I think I am just going to yank all the lines I have yet to replace and do it all in 1 go, then I can see if it is the canister or not. So far so good!
Another question though, when setting the vacuum idle on an automatic I know you should do it in drive with someone mashing down on the break. I did that and the vacuum was only reading around 8, seems very low. Any thoughts on this or why?
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Heads
http://www.summitracing.com/parts/SUM-162111/
Intake Gasket
http://www.summitracing.com/parts/FPP-1256/?rtype=10Justin
http://www.summitracing.com/parts/SUM-162111/
Intake Gasket
http://www.summitracing.com/parts/FPP-1256/?rtype=10Justin
FYI ... must of what I'm pointing to is alluded to in the "notes" section for those heads on the summit site ... just look.
FYI ... those are great heads. IF the above is source of your leaks and your intake's runners' "footprint" is not too small ... you might fix it with a combination of both rtv silicone sealer & best-fit gasket.
FYI ... take a look at OTHER heads w/ runners about 200cc & compare ... majority of them run a smaller 1204 or 1205 int gasket.
G'Luck!
Cruising
Joined: Jan 2010
Posts: 11
Likes: 0
From: Friendswood Texas
Jackson,
Sure as S**T I sprayed some starter fluid around the manifold and right near the drivers side gasket base I found a spot where when I sprayed it the engine revved up! Sooooooo looks like I need to get some more sealer and another gasket, I will let you know how it turns out tomorrow!
Sure as S**T I sprayed some starter fluid around the manifold and right near the drivers side gasket base I found a spot where when I sprayed it the engine revved up! Sooooooo looks like I need to get some more sealer and another gasket, I will let you know how it turns out tomorrow!
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Jackson,
Sure as S**T I sprayed some starter fluid around the manifold and right near the drivers side gasket base I found a spot where when I sprayed it the engine revved up! Sooooooo looks like I need to get some more sealer and another gasket, I will let you know how it turns out tomorrow!
Sure as S**T I sprayed some starter fluid around the manifold and right near the drivers side gasket base I found a spot where when I sprayed it the engine revved up! Sooooooo looks like I need to get some more sealer and another gasket, I will let you know how it turns out tomorrow!
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
I don't KNOW if your intake can seal. Maybe, maybe not.
For now, suggest you set $300 aside.
And pull intake off & check & measure & see if you can make what you have fit w/ some silicone & best-fit gasket.
There may be no readily available intake that fits both YOUR hood and YOUR heads. Maybe, maybe not. You might mod your intake w/ bead of heliarc weld around outside of runners & a few hours work w/ a flatfile. Maybe, maybe not. Again, First see if you can seal what you have w/ rtv & gasket ... don't guess/speculate, do check & measure.
BTW, ANY grade/color silicone works for this. There is a GREY color commonly available.
For now, suggest you set $300 aside.
And pull intake off & check & measure & see if you can make what you have fit w/ some silicone & best-fit gasket.
There may be no readily available intake that fits both YOUR hood and YOUR heads. Maybe, maybe not. You might mod your intake w/ bead of heliarc weld around outside of runners & a few hours work w/ a flatfile. Maybe, maybe not. Again, First see if you can seal what you have w/ rtv & gasket ... don't guess/speculate, do check & measure.
BTW, ANY grade/color silicone works for this. There is a GREY color commonly available.
Cruising
Joined: Jan 2010
Posts: 11
Likes: 0
From: Friendswood Texas
Still having issues =/,
I replaced the intake gasket with the fp 1206 as recomended, took a lot of time cleaning and making sure everything is sealed correctly. I get it all back together, make sure timing is correct, check for leaks and all seems good. The way it is running though is weird I don't even have to road test the car to tell something is wrong. I tried to record the audio to play but it was very muffled the best way I can describe it is it starts out fine then it seems like it bogs down for about 3 seconds so it would be like (Normal Normal Normal, Bog Bog Bog, Normal Normal Normal, Bog Bog Bog.) It really seems like a vacuum leak but I had everything plugged except the vacuum advance. Any other ideas??? I am about out... I retested the carb and the intake using starting fluid again and never noticed a difference like I did before I replaced the gasket. Ohh also the vacuum when I am in drive with the break pressed is up to 11, and yes it runs like this with every vacuum line connected or disconected and plugged.
Justin
I replaced the intake gasket with the fp 1206 as recomended, took a lot of time cleaning and making sure everything is sealed correctly. I get it all back together, make sure timing is correct, check for leaks and all seems good. The way it is running though is weird I don't even have to road test the car to tell something is wrong. I tried to record the audio to play but it was very muffled the best way I can describe it is it starts out fine then it seems like it bogs down for about 3 seconds so it would be like (Normal Normal Normal, Bog Bog Bog, Normal Normal Normal, Bog Bog Bog.) It really seems like a vacuum leak but I had everything plugged except the vacuum advance. Any other ideas??? I am about out... I retested the carb and the intake using starting fluid again and never noticed a difference like I did before I replaced the gasket. Ohh also the vacuum when I am in drive with the break pressed is up to 11, and yes it runs like this with every vacuum line connected or disconected and plugged.
Justin
