I recently rebuilt my 351 and now notice there is a lot of valve Lash. I knew it would increase with the roller rockers however it seems to be a little excessive. So far the Modifications I have done that could affect this are: Power Max Cam 2020 (444211), with matching springs. Ford Racing roller rocker 1.6 (M-6564-B351). The heads were resurfaced, and replaced the stock pushrods with Chromemoly 5/16 in 7.550 hardened with ball ends. (Matched the same size as stock) I have tried to readjust them a few times with no luck still loud. Starting to think the rods are the wrong size thinking they need to be longer, Any help would be appreciated, thanks.
Feel your pain. I had this happen to me! except I used an Edelbrock RPM cam kit, they forgot to mention on their site AND in the instructions... I needed an adjustable valve train. Did you do a stud and guide plate conversion kit?
I have roller rockers and the stud kit. I now have a fully adjustable valve train. I would call your cam manufactorer and ask about your cam if you need an adjustable valve train.
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Anytime you go with a roller valvetrain you should make it adjustable for serviceability alone. I believe they make a kit so you can put studs in without having to take it to a machine shop to have the pedestal resurfaced.
Good Luck
Anytime you go with a roller valvetrain you should make it adjustable for serviceability alone. I believe they make a kit so you can put studs in without having to take it to a machine shop to have the pedestal resurfaced.
Good Luck
I actually have used the stud kit from Crane cams. It converts the pedestals to studs to run and adjustable valve train. Its Crane Cams. I think it costed me $300 or so to get the stud kit and full roller rockers.
In the stud kit they send you studs, guide plates and guide plate bushings. Really easy to convert.
__________________
"Speed costs money, How fast do you wanna go?"
"rumor is you could F**K up an iron ball with a rubber hammer"
Your pushrods are way short. Older 351w's use an 8.152 and newer @78?-up use 8.182. I'm not sure but I think you have 302 stock length pushrods. Northern Auto Parts ( 1-800-831-0884) sells an adjustable pushrod length checker (7.5-8.7) part #7901-1 for $12.99. With it you can center your rockers on your valve stem tips and eliminate any doubt as to what length pushrods are ideal for your set-up. You can get one from Summit and a few other places, but not at that price.
Couple of questions, when you say you have lash how much - use a feeler gauge?
Are you running screw in studs in the heads or any other "crutch" decribed above so you can adjust lash?
To begin to determine if the pushrods are even in the ballpark, pull off an intake and exhaust rocker with the cam on the base circle (no lift) and use a black or red sharpie (permanent) to color the end of the valve with (where the roller tip would be at) . Now adjust the lash to zero if you can (I have always had to set the lash to zero in any perfomrance application or where the cam, lifters, and rockers are aftermarket like yours, no matter if is hydraulic or solid). Now turn the engine over 3 or 4 times, pull the rockers off and check the wear pattern. Do not worry about it being directly centered in the middle of the valve, it rarely is, you want to get the least amount of sweep possibile on the end of the valve. For your application I would say anything less than .050 would be good.
I would be willing to bet your pushrods are not near long enough, I am running an 8.350 in my 351. All engines wil be different and must be checked, usually a GOOD machine shop would do this.
Last edited by 70BOSS 302 : 01-16-2008 at 10:17 AM.
What? Im a carpenter, and I know what Alder is, I use that wood every now and again. Still sounds like your pushrods are too short to me. I don't know what a '95 is supposed to use , but a quick check at Summit lists 7.700 or 8.144 as their only choices for a 95 351w. I know they don't sell every length, though. I'd still buy a checker or have someone check length with one. (Hmmmmm... You never mentioned lifters.).
Lifters were hydrolic roller and replaced matched to stock, and the push rods were matched length agenst the ones i pulled out of the the motor when i rebuilt it, and were the same length as the ones i pulled out it could be i wrote down the wrong lenght in the original post but i did compair them and they matched to ones that were in it with the stock rockers and no noise.
AHA! That explains the shorter pushrods, (I was thinking flat tappet hydraulic). I know what hydraulic roller lifters are and I've seen them on E-Bay, and that's about as far as my vast knowledge(lol) extends in this area. This new info should spawn a reply or 2 from someone with "hands-on" experience in this area-meanwhile, a few "non-sensible ravings from a lunatic mind"- (Young Frankenstein).... #1: The roller rockers have changed the geometry and require longer pushrods: perhaps this is the exact reason Summit offers 7.700 length. #2 A problem with the new lifters? Did you check how far the plunger sat below the top of the lifter compared to the old? #2 is kinda out there, but I heard of that problem before, but not in this application. Since I can't give you any real solution, I'll offer this for your consideration: go to Summit Racing online and they have an "ask the Tech" option. Go there and punch in everything else you have except the pushrods and ask for a length, It might solve your problem.
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