Quote:
When you say you installed the 'factory' lifters, do you mean the OE lifters that were in the engine prior to the cam change, if so did you have them re-surfaced?
Yeah, I just thought of the horror of that...
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| All exhaust valves sticking ???? https://slantsix.org/forum/viewtopic.php?t=60860 |
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| Author: | mikewilliams [ Thu Mar 02, 2017 11:49 am ] |
| Post subject: | All exhaust valves sticking ???? |
Well this is what's going on, I sent my head out to have it rebuilt, Got it back and bolted on the engine and all the exhaust valves are sticking, took the head off and took the valves out and clean them and change the valve springs for the new cam, put it back on the engine and the exhaust valves are still sticking WTF. The only thing that I can think of is that the valve keepers are hanging up on the valve seals???????Anything that you guys can think of, Please reply. Thanks Mike |
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| Author: | CNC-Dude [ Thu Mar 02, 2017 12:46 pm ] |
| Post subject: | |
Valve guide clearance too tight possibly. |
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| Author: | mikewilliams [ Thu Mar 02, 2017 12:52 pm ] |
| Post subject: | |
Quote: Valve guide clearance too tight possibly.
No, when I took the valves out, they fell into my hands with no problem.
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| Author: | lgu32 [ Thu Mar 02, 2017 12:56 pm ] |
| Post subject: | |
My slant bent 3 exhaust valves at 3 separate accidents. All of them happened at high rpm full throttle and afterward the valves move easily at their liners. I have bronze guides and stainless valves and they are machined "not too tight" after 1st damage. I also do not use any seals at exhaust valves. Only thing which helped was extra strong valve springs. I assume slant head goes hotter than heads usually and because stainless valves enlarge more than bronze guides - they stick when hot. I use ethanol fuel which could also cause something. |
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| Author: | DusterIdiot [ Thu Mar 02, 2017 2:27 pm ] |
| Post subject: | What cam? |
What cam and springs did you install?... you can also have valve guide clearance issues if the cam has a high lift and the heads aren't turned down adequately to clear the retainer and keeper at max lift hot. Are your new springs the dual damper variety and did you give to the machinist to install when he finished the guides? When you say they stick... are you saying that when you sweep the crank over and there is no pressure on the exhaust rocker arm that the valve stays in the open position and doesn't return or takes a moment to snap back? |
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| Author: | mikewilliams [ Fri Mar 03, 2017 5:48 am ] |
| Post subject: | |
I FIXED IT... Here what took place...I ordered a new cam and solid lifters from Comp. Cams, and I though that the lifters looked a little funny to me, with a snap ring on the top of the lifter, but what do I know, anyway installed the cam and lifter's and then had stuck valves, here's what was going on, the push rod was getting caught up on the snap ring ridge and then falling into the lifter bottom, and that was giving the effect of sticking valves..So I replaced the lifter's with the factory one's and it all work's GREAT. I will let Comp. Cam's know that they have poor design. Thanks Guy's Mike |
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| Author: | DusterIdiot [ Fri Mar 03, 2017 4:16 pm ] |
| Post subject: | Ummm... |
Quote: I though that the lifters looked a little funny to me, with a snap ring on the top of the lifter, but what do I know,
Did you check to sere if they had a spring in the body or the middle acted like a plunger? Normally Comp's solid lifters are machined solid with no snap ring... but the hydraulic lifter on the other hand is exactly as described... what is the comp cam number and or kit you ordered?
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| Author: | DadTruck [ Fri Mar 03, 2017 7:10 pm ] |
| Post subject: | |
When you say you installed the 'factory' lifters, do you mean the OE lifters that were in the engine prior to the cam change, if so did you have them re-surfaced? And I agree with DI, sounds like comp sent you hydraulic lifters, did you order or get a hydraulic cam?? |
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| Author: | DusterIdiot [ Fri Mar 03, 2017 8:06 pm ] |
| Post subject: | x2 |
Quote: When you say you installed the 'factory' lifters, do you mean the OE lifters that were in the engine prior to the cam change, if so did you have them re-surfaced?
Yeah, I just thought of the horror of that...
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| Author: | SpaceFrank [ Fri Mar 03, 2017 10:55 pm ] |
| Post subject: | |
Yeah, sounds like Comp Cams sent you hydraulic lifters with your solid cam. ...are you sure they sent you the right cam? |
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| Author: | mikewilliams [ Sat Mar 04, 2017 3:18 am ] |
| Post subject: | |
I ordered an solid lift Cam L 7266-16 and they supplied the lifters # 821 also on the lifter box it said solid lifters. I thought that the lifter looked funny because not only did it have a snap ring inside of it, it also had a little movement in the top with no spring ?? I did send Comp. Cam an e-mail yesterday but have not received a reply as of yet. I think you guys are right, wrong lifters, in the right box. Thanks Mike |
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| Author: | mikewilliams [ Sat Mar 04, 2017 3:23 am ] |
| Post subject: | |
I call them a couple week ago and had them check the cam number and they told me that it was a solid lift cam, I did not have the lifters resurface as they were not very old and still flat. Mike |
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| Author: | SlantSteve [ Sat Mar 04, 2017 5:53 am ] |
| Post subject: | |
Solid lifters with a snap ring to retain the push rod cup are pretty common. I just got a set of Edm oiling solid lifters from Bullet Cams that are the same.They look like hydro lifters but obviously aren't,so you can't just see a snap ring and assume it's a hydro lifter. Comp 821 is indeed a solid lifter number,now,what you have in the box may or may not be a solid, obviously we can't tell,but it's certainly possible they are incorrectly packaged,I wouldn't put anything past Comp Cams. They are no doubt mainly sold as small block lifters and they prob haven't encountered this issue with them until now. Best to get those used solids faced up before you run them on a new cam, no matter how good they look. You may get away with it on a slant with low spring pressures,but...you might not either. |
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| Author: | DadTruck [ Sat Mar 04, 2017 6:38 am ] |
| Post subject: | |
Quote: not very old and still flat.
flat lifters, whether mechanical or hydraulic are not really 'flat' on the face that contacts the camthe running face of the lifter will have a very minute convex shape to it, that coupled with the intentional placement of the lifter bore silghtly off center of the cam lob results in the lifter spinning in its bore as the lifter transverses over the running surface of the cam. that action allows an oil film to wash in between the running surface of the cam and lifter. Typically lifters and cams seat to them selves during the initial cam run in period,, initial 20 minutes. The recommended practice is to use new or re ground lifters with a new cam or with a used cam if the original lifters matched to specific cam lobs are not available. |
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