302 pushrod/valve gap
Thread Starter
|
Freshman User
Joined: Oct 2003
Posts: 47
Likes: 0
From: Delhi, Ontario
302 pushrod/valve gap
I just freshened up my 302 in my '84, putting in a camshaft kit - cam, lifters and timing chain. I didn't have the tool to push down on the rockers when I was putting it all back together, but everything was going back stock, no valve work, so they should be fine. However, I have so much valve noise now it sounds like a diesel. I made my own tool and compressed the lifters down to check the clearance and I am getting 0.281". I can't remember the upper limit, but I thought it was around 0.170". What could be causing this? To my knowledge, the pushrods are stock length. I know you can get longer ones, but this seems really excesive. Anyone have similar problems?
Elder User
Joined: Apr 2003
Posts: 627
Likes: 1
I assume you have pedestal mt. rockers and have tightened them fully. You had the valves ground and this will cause the valve stem to protrude further above the head and in effect weaken the spring pressure.they then shim the springs to restore the correct height and pressure. As a result most head shops grind the valve stem a equivalent amount, sounds as though yours were ground off to much giving you excess clearance that the lifters can't take up.this will also affect the geometry and cause adverse wear if it's the case, because the rocker wont be in the right place on the valve stem at mid lift.
Elder User
Joined: Apr 2004
Posts: 544
Likes: 0
From: Ocala, Florida
Go to www.compcams.com and click on the online catalog. Find pushrod geometry pages 306 and 307 and click on it. Read it, I hope it helps.
Elder User
Joined: Sep 2004
Posts: 500
Likes: 0
From: midwest
have you run the motor long or at least more then once? stupid as it seems the lifters may not be pumped up if you just started it once. i have had the same problem and if you shut it off and then restart it the noise goes away if thats the cause. just something to check.....
Thread Starter
|
Freshman User
Joined: Oct 2003
Posts: 47
Likes: 0
From: Delhi, Ontario
I did run the engine for about a year before I did a trans swap and other things, and decided to add the new cam/lifters. They did not make any noise like they are now. I didn't touch the valves (didn't even have the heads off)They are torqued correctly, and I have been running them for a few weeks now. I know not good to drive too much, but its is all I have to drive right now. It really doesn't make any sense. Only thing I can think of is the lifters I got in the kit were not right. When I installed them, I compared to the old ones and they seemed the same, but maybe the internals are different.
Thread Starter
|
Freshman User
Joined: Oct 2003
Posts: 47
Likes: 0
From: Delhi, Ontario
They rattle through the entire RPM range. It actually is causing the engine to run rough at idle, and high RPM. When loaded, it quiets out some and smooths out.
Trending Topics
Elder User
Joined: Apr 2003
Posts: 627
Likes: 1
how radical is your cam? I put a fairly radical cam in a engine recently that I couldn't get quiet and in conversation with Comp Cams they thought the noise was actually the valves hitting the seats when closing and was due to the sharp ramp off on the cam and I should just live with it, I changed the cam out to one with less duration and it quietened down significantly.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Hotshot
Joined: Dec 2003
Posts: 18,423
Likes: 9
From: iowa
I have 2 questions, and will give you what I found on a comp cam, first the questions are there any shims under your rockers? #2 when you installed the rockers I know you compressed the lifters but instead of that did you happen to tighten one just till it was at zero lash (pushrod no longer spins freely with one finger) then finish tightening up the rocker and watching how far you have to turn it if it is less than 1/4 turn you are going to have to get slightly longer pushrods.
I changed one comp cam for another they were alittle more cam than you are running but they both were from the comp extreme series of cams, and the second cam appeared to be ground on a slightly smaller base circle, and I had to get .050 longer pushrods, you may have the same problem.
I changed one comp cam for another they were alittle more cam than you are running but they both were from the comp extreme series of cams, and the second cam appeared to be ground on a slightly smaller base circle, and I had to get .050 longer pushrods, you may have the same problem.
Thread
Thread Starter
Forum
Replies
Last Post
oneofakind97
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
6
Mar 7, 2015 10:27 AM
FossenRacing
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
2
Oct 2, 2014 01:29 PM
capriceragtop
1987 - 1996 F150 & Larger F-Series Trucks
11
Apr 16, 2014 02:14 PM
timbersteel
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
16
Apr 11, 2014 12:32 PM
