Excessive Pushrod Wear!?
Thread Starter
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
Chris speaks the truth. Folks don't realize just how critical each and every component is to the engine assembly.
When I had my engine built, we installed the rotating assembly before ordering the heads and valves.
Then we measured the piston clearance before we ordered the head gasket.
Then we ordered the lifters and rockers after we mocked up the valve train and took some measurements.
Then we ordered the pushrods after we measured the SYSTEM of my rockers, my lifters, my heads, my head gasket, and my valves and the resulting relationship between my studs, my head casting, and the height of my TDC piston.
And all of this was done while also considering my cam profile, compression ratio, and spring rates.
I understand that you are where you are and would like the thing to run, but changing even one component to anything outside of stock in this entire engine system is a bigger deal than Summit/Jegs makes it out to be.
When I had my engine built, we installed the rotating assembly before ordering the heads and valves.
Then we measured the piston clearance before we ordered the head gasket.
Then we ordered the lifters and rockers after we mocked up the valve train and took some measurements.
Then we ordered the pushrods after we measured the SYSTEM of my rockers, my lifters, my heads, my head gasket, and my valves and the resulting relationship between my studs, my head casting, and the height of my TDC piston.
And all of this was done while also considering my cam profile, compression ratio, and spring rates.
I understand that you are where you are and would like the thing to run, but changing even one component to anything outside of stock in this entire engine system is a bigger deal than Summit/Jegs makes it out to be.
Does anyone have any experience with the Summit aluminum roller rockers I listed earlier? They appear to be very similar to the Scorpians which is what I believe are listed for AFR heads. I will most likely stick with the 1.5's.
Last edited by Jartanyon; Jun 9, 2014 at 12:54 PM.
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
Oh, believe me…having rebuilt my entire engine myself with the guidance of some really awesome people on here, I realize the importance of everything playing together. I just took someone else's word (actually two people) for the last step when I should have measured it myself (not people on this forum). I think I was overwhelmed with being so close to the finish line that I wasn't thinking straight! Oh well, yet another lesson learned in this journey.
Does anyone have any experience with the Summit aluminum roller rockers I listed earlier? They appear to be very similar to the Scorpians which is what I believe are listed for AFR heads. I will most likely stick with the 1.5's.
Does anyone have any experience with the Summit aluminum roller rockers I listed earlier? They appear to be very similar to the Scorpians which is what I believe are listed for AFR heads. I will most likely stick with the 1.5's.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
I haven't heard any complaints about summit aluminum rockers but I never used them. I did buy their cheap stamped steel roller rockers for use with a mild performance cam on a plow truck. Never had any problems with about 30,000 miles. Truck rusted out before engine ....
Thread Starter
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
Ok, got the adjustable pushrod today. Dumb question...how are you supposed to use the adjustable pushrod if the nuts used to adjust it wont go past the guide plates?
Last edited by Jartanyon; Jun 11, 2014 at 06:35 PM.
Race Director
Joined: Dec 2004
Posts: 10,332
Likes: 63
From: PARADISE
St. Jude Donor '09-'11-'12-'13-'14
I use the type without a jam nut. It's a friction fit rather than a locknut. Your type may have to come up through the bottom, assuming you have the manifold off. You might also be able to do it with the guide plate off since you have the light springs. You can center the rocker arm on the stem easily by hand with them off.
Thread Starter
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
I got it to work by taking the nut off and then used masking tape around the threads to lock in the length.
Ok, so the first run was at 7.875 on the exhaust- that looks a little too much right?
This one was at 7.750 on the intake which was nearly identical to the 7.800 that was in there. Thoughts?
Ok, so the first run was at 7.875 on the exhaust- that looks a little too much right?
This one was at 7.750 on the intake which was nearly identical to the 7.800 that was in there. Thoughts?
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Thread Starter
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
Something else interesting. Here is the wear patter on cylinder 8 intake from before - looks a tad short, but not bad.
Here is exhaust on number 8 - this is the one I kept having to adjust. That looks like it is from the pushrod being shorter. Since the pushrod on that one came out OK, I think it looks more like a lobe wiping in the process.
Here is exhaust on number 8 - this is the one I kept having to adjust. That looks like it is from the pushrod being shorter. Since the pushrod on that one came out OK, I think it looks more like a lobe wiping in the process.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
That adj p-rod is the most difficult tool i have ever tried to use. And i had the intake off trying it. Im convinced it is for use with the engine on the stand - not in the car. Much much faster using a rocker type checker.
Try one of these:http://www.summitracing.com/parts/man-42137/overview/
or this:http://www.summitracing.com/parts/pro-66789/overview/
Ok, from those pix i really dont see a bad wear pattern. U just want to keep the rocker tip off the edge to prevent side loading - not rocket science. IMHO i think u have gone beyond the effort and definitely the expense of just removing the intake to look at the lifters/lobes.
Good luck,
cardo0
Try one of these:http://www.summitracing.com/parts/man-42137/overview/
or this:http://www.summitracing.com/parts/pro-66789/overview/
Ok, from those pix i really dont see a bad wear pattern. U just want to keep the rocker tip off the edge to prevent side loading - not rocket science. IMHO i think u have gone beyond the effort and definitely the expense of just removing the intake to look at the lifters/lobes.
Good luck,
cardo0
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
The wear pattern should be justified to the exhaust side of the valve tip. If it is CENTERED on the valve tip it is WRONG. The wear pattern should be no wider than .060", off center to the exhaust side of the tip.
That last picture of that exhaust valve looks to have quite a bit of "wear" across the top.
That last picture of that exhaust valve looks to have quite a bit of "wear" across the top.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
How can any "off-center" tip contact be good for the vlv guide? The patch pattern size is dependent on the lift of the cam and travel of the rocker arm tip. The pattern should centered as possible and equidistant over the center of the vlv tip.
That rocker style p-rod checker will measure the p-rod difference faster than u can make a phone call Justin. Leave those adj p-rods for the NASCAR kids.
That rocker style p-rod checker will measure the p-rod difference faster than u can make a phone call Justin. Leave those adj p-rods for the NASCAR kids.
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
How can any "off-center" tip contact be good for the vlv guide? The patch pattern size is dependent on the lift of the cam and travel of the rocker arm tip. The pattern should centered as possible and equidistant over the center of the vlv tip.
That rocker style p-rod checker will measure the p-rod difference faster than u can make a phone call Justin. Leave those adj p-rods for the NASCAR kids.
That rocker style p-rod checker will measure the p-rod difference faster than u can make a phone call Justin. Leave those adj p-rods for the NASCAR kids.
http://www.circletrack.com/techartic...p_rockers.html
It doesn't matter if the cam is .450" lift or it is 1.100" lift. That pattern should be no wider than .060". My years working for a rocker mfg taught me this.
Thread Starter
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
Now I am confused. I have read in other articles that you want to have the wear start just before center line and end just after?? Are you saying the first photo I posted is more accurate then since it is over center and more towards exhaust?
I appreciate both of your input and will give Scott a call today - can't have too much info
I appreciate both of your input and will give Scott a call today - can't have too much info
Drifting
Joined: Jul 2013
Posts: 1,299
Likes: 93
From: Tri-Cities TN
Now I am confused. I have read in other articles that you want to have the wear start just before center line and end just after?? Are you saying the first photo I posted is more accurate then since it is over center and more towards exhaust?
I appreciate both of your input and will give Scott a call today - can't have too much info
I appreciate both of your input and will give Scott a call today - can't have too much info
We answer this question an average of 3 times a week. Some don't even have our products and are not able to get the information from who they bought it from because all they have is price....no tech.
Justin,
Call and ask for Scott. You need to be at the engine and have a rocker arm and a polylock.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
Try it both ways. That is how we learn. I can tell you basing your geometry on getting it in the center will cost you lift. Doing it the way I have linked to will yield you correct geometry and closest to max lift.
We answer this question an average of 3 times a week. Some don't even have our products and are not able to get the information from who they bought it from because all they have is price....no tech.
Justin,
Call and ask for Scott. You need to be at the engine and have a rocker arm and a polylock.
We answer this question an average of 3 times a week. Some don't even have our products and are not able to get the information from who they bought it from because all they have is price....no tech.
Justin,
Call and ask for Scott. You need to be at the engine and have a rocker arm and a polylock.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Thats not true. The sweep of a rocker tip is a function of vlv lift and the rocker ratio. In extreme cases lash caps are used to increase the vlv tip area for this.
And Smokey Y. (may he rest in peace) said the critical point for geometry is never let the contact point get closer than 0.20" to the edge. That is the important critiria.
And that Circle Article used Smokey for its VTG reference. And i have his Power Secrets right next to me to prove what i say. Reading that CT art says the roller moves in the exh direction - not centered on the exh side. Did u even read your own reference article??? Heres a quote: The critical element is not the positioning of the sweep path on the valve tip; it is the geometric angles of the rocker pivots to the valve stem.
Of course, we don't want to see the roller rocker contact point move any closer than 0.020 inch to the edge of the valve stem, as Smokey has stated, but being off-centered has little negative effect on components such as valve guides and valvetrain harmonics and no effect on performance.
The more i read your posts the more it reads like you are running your mouth hoping no-one will look it over and challenge u.
BTW do own a corvette???
And Smokey Y. (may he rest in peace) said the critical point for geometry is never let the contact point get closer than 0.20" to the edge. That is the important critiria.
And that Circle Article used Smokey for its VTG reference. And i have his Power Secrets right next to me to prove what i say. Reading that CT art says the roller moves in the exh direction - not centered on the exh side. Did u even read your own reference article??? Heres a quote: The critical element is not the positioning of the sweep path on the valve tip; it is the geometric angles of the rocker pivots to the valve stem.
Of course, we don't want to see the roller rocker contact point move any closer than 0.020 inch to the edge of the valve stem, as Smokey has stated, but being off-centered has little negative effect on components such as valve guides and valvetrain harmonics and no effect on performance.
The more i read your posts the more it reads like you are running your mouth hoping no-one will look it over and challenge u.
BTW do own a corvette???