Push-rod problems with new TrickFlow heads.
Thread Starter
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
Push-rod problems with new TrickFlow heads.
This past weekend I was trying to install and adjust my rockers (Comp cam stemped steel roller tips) and pushrods on my new Trickflow heads (23 Deg.) and bottomed out the adjusting nuts with room to spare. After removing the nuts and holding the rocker in place against the push-rod and valve, I could see the end of the threaded portion of the new ARP studs and about a 1/16" of smooth shaft above the nut seating surface. Obviously, the pushrods were WAY too short. They were the ones recommended by Summit when I purchased the heads. I've called them back (their technical line) twice now and they don't even agree with one another as to the correct pushrod ligenth. Several of the people told me that this setup should use stock (7.850) rods and today, another person there told me they require a very long (8.350) rod.
I can't be the first person to install 23 deg. Trickflow heads on a 350 cid engine with these Comp cam Magnium Steel roller tip rockers.
Has anyone out there done this and remember their push-rod measurement?
I can't be the first person to install 23 deg. Trickflow heads on a 350 cid engine with these Comp cam Magnium Steel roller tip rockers.
Has anyone out there done this and remember their push-rod measurement?
Melting Slicks
Joined: Apr 2001
Posts: 2,104
Likes: 220
From: Ca.
Re: Push-rod problems with new TrickFlow heads. (Strike3)
I also have the tf 23 deg heads, but on a 406 with comp full roller rockers 1:6 ratio with a flat tapp hyd cam. Due to the ratio I needed SLIGHTLY diff. lengh pushrods from the stock 7.850. Something ain't right! Are the rocker studs torqued on; just to double check adjustment- with that cyl at tdc- turn down the nut just till the play is out of the rocker-then turn no more than one more turn and thats it, Yea??? If you have a roller cam then the pushrod lengh is actually shorter....Also to really check your valvetrain geometry-as in get the rocker to center on the top of the valve- you need to temporarly use a solid lifter.
[Modified by drive it, 12:44 AM 9/6/2001]
[Modified by drive it, 12:44 AM 9/6/2001]
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
Re: Push-rod problems with new TrickFlow heads. (drive it)
you really should get a push rod length checker. There are inexpensive and will enable you to get the correct push rod. My experience with the techs at summit is that they allways sound totally confident in what they are say, BUT they are rarely correct. Getting the correct push rod length depends on so many variables (cam base circle, deck height, heads, valve length, install height, rockers, etc.) that it would be alomost impossible to give you a length over the phone. That is why they have length checkers.
good luck getting it setup right
good luck getting it setup right
Safety Car
Joined: May 1999
Posts: 3,588
Likes: 1
From: Volcano, HI
Re: Push-rod problems with new TrickFlow heads. (ralph)
I am using a set of TFS twisted wedge heads. They were a pain to setup correctly. The intakes used not only a different pushrod, but a different rocker arm (special 1/2 set made by comp cams) to get the geometry right. On the positive side, they flow really well with better velocity than most heads flowing the same rate.
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
Re: Push-rod problems with new TrickFlow heads. (Strike3)
I have a 406 that uses TF Twisted wedge and my pushrods had to .100 longer than the stock. I also used the crane cams gold race rocker arms on that application.
Melting Slicks
Joined: Jun 2001
Posts: 2,429
Likes: 14
From: CA
Re: Push-rod problems with new TrickFlow heads. (Strike3)
I'm not sure if I understand the problem. Are you running out of thread on the lower part of the rocker stud?
I just installed a pair of Dart Pro 1's & Crane Forged rockers and the studs were way too short.
If you are interested, I have 2 sets of shorter rocker studs & a set of poly locks designed for stamped rockers. Let me know.
As for the geometry, you want the roller tip in the center of the valve tip at half lift. This is easy to watch as you turn the motor over by hand with the plugs out.
I just installed a pair of Dart Pro 1's & Crane Forged rockers and the studs were way too short.
If you are interested, I have 2 sets of shorter rocker studs & a set of poly locks designed for stamped rockers. Let me know.
As for the geometry, you want the roller tip in the center of the valve tip at half lift. This is easy to watch as you turn the motor over by hand with the plugs out.
Racer
Joined: Jun 2001
Posts: 269
Likes: 1
From: Annapolis MD
Re: Push-rod problems with new TrickFlow heads. (Strike3)
I called trick flow directly at 330-630-1555 and a real person picked up the phone on the second ring. I told him what harware combination I was using and within seconds he had a part# for me. (Trick Flow pushrods of course!)
Andy B http://vette.20m.com
Andy B http://vette.20m.com
Melting Slicks
Joined: Apr 2001
Posts: 3,399
Likes: 278
From: Olmsted Falls, Ohio
Re: Push-rod problems with new TrickFlow heads. (Strike3)
From your description of the problem, it sounds like the rocker stud threads do not come down far enough. If you cannot tighten up the rocker without a pushrod installed then the stud usable-thread length is wrong for your application.
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Thread Starter
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
Re: Push-rod problems with new TrickFlow heads. (KenSny)
I called Trick Flow today and the fellow I talked with said they should be at least .100 longer than stock by design.
I appreciate all the help and have decided to buy a solid lifter tool and adjustable pushrod, If I can find a supplier.
Thanks again.
I appreciate all the help and have decided to buy a solid lifter tool and adjustable pushrod, If I can find a supplier.
Thanks again.
Drifting
Joined: Aug 2000
Posts: 1,316
Likes: 0
From: Houston, TX
Re: Push-rod problems with new TrickFlow heads. (Strike3)
Ralph is right, you need a push rod length checker to determne the correct length of the push rods for your engine. All the variables he mentioned come into play. this won't be fixed over the phone.
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Re: Push-rod problems with new TrickFlow heads. (Strike3)
I used 7.850" push rods (Comp Cams brand). That was Trickflows recommended length. I didn't verify them with an adjustable pushrod length tool but I studied the contact point of the rocker tip vs. the valve stem while rotating the engine and it appeared to be fine.
However, we had a problem very similar to yours the first time we attempted to adjust the valves while the engine was on the stand. We finally figured out that we were using the wrong timing chain cover. The timing indicator tab was in the wrong location. It was a real head scratcher but we finally sorted it out. As you described, we had to screw the nuts almost to the bottom of the studs to get what appeared to be the correct setting.
After reading your post, and hearing that Trickflow recommended 0.100" longer that what I'm using, I'm feeling uneasy about mine. I have also read some posts recently saying that it is not recommended to use the "pushrod spin method" to determine Zero lash. That's the method we used and then we tightened them an extra 3/4 turn. I'm now wondering if they are too tight
Good luck and I'll certainly be watching this thread to see the outcome.
However, we had a problem very similar to yours the first time we attempted to adjust the valves while the engine was on the stand. We finally figured out that we were using the wrong timing chain cover. The timing indicator tab was in the wrong location. It was a real head scratcher but we finally sorted it out. As you described, we had to screw the nuts almost to the bottom of the studs to get what appeared to be the correct setting.
After reading your post, and hearing that Trickflow recommended 0.100" longer that what I'm using, I'm feeling uneasy about mine. I have also read some posts recently saying that it is not recommended to use the "pushrod spin method" to determine Zero lash. That's the method we used and then we tightened them an extra 3/4 turn. I'm now wondering if they are too tight
Good luck and I'll certainly be watching this thread to see the outcome.
Drifting
Joined: Feb 2000
Posts: 1,607
Likes: 0
From: Clarksville,Tn,USA TN
Re: Push-rod problems with new TrickFlow heads. (MIKER)
I also have TFS 23 degree heads on my 388CU. I used 7.850 as trick flow suggested in the comp brand. I also have roller tip rockers. Everything looked good.
Neil in Tenn
Neil in Tenn
Thread Starter
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
Re: Push-rod problems with new TrickFlow heads. (Nomad78SA)
I called Comp Cam today and ordered a pushrod checker. Between Summit and TrickFlow I've had recommendations varing a total of .500" (7.850 to 8.350). There's no way a variation in gasket thickness and deck machining could range even a fraction of that. The machining of my decks and use of a thinner head gasket would through the equasion toward the need for a shorter pushrod, not longer. Anyway, I'm just rambeling out of frustration. Thanks again for all your response. I appreciate it.
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Re: Push-rod problems with new TrickFlow heads. (Strike3)
I am using stock length CC pushrods with my setup. When I checked the contact pattern on the valves, it was right in the center.
Thread Starter
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
Re: Push-rod problems with new TrickFlow heads. (glen242)
Thanks glen242! I just don't understand it! Sounds like your running the same cam (CC grind 12-242-2), the same heads, the same push rods and the same rockers. Yet with my adjusting nut tightened all the way down (Too the end of the threads on the stud), I still have enough space such that I can still lift out the pushrods. Anyway, my new adjustable rod checker should be here next week and hopefully answer my questions.
Thanks again, Bill Pike
Thanks again, Bill Pike
Thread Starter
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
Re: Push-rod problems with new TrickFlow heads. (Strike3)
Latest update..........
I ordered a pushrod checker from Comp Cams last Monday and received it yesterday. Last night I used the checker to establish the ideal ligenth for my setup. It came out 8.250", about standard + .400".
This morning I called Trickflow with this information and they decided they must have included the wrong (too long) rocker arm studs. They have a new, shorter set on their way to me now. All free of charge of course.
Hopefully, the end of the delima.
Thanks again one and all. Bill
I ordered a pushrod checker from Comp Cams last Monday and received it yesterday. Last night I used the checker to establish the ideal ligenth for my setup. It came out 8.250", about standard + .400".
This morning I called Trickflow with this information and they decided they must have included the wrong (too long) rocker arm studs. They have a new, shorter set on their way to me now. All free of charge of course.
Hopefully, the end of the delima.
Thanks again one and all. Bill
