having some slight cam issues.

[66redrocket]

This is my first major build/restore. 66 f100, has a 360 in front of a stock 4 speed. not so stock parts include flow-tech long tube headers, comp cam double roller timing set, comp cams thumper cam with .501 int lift and .515 exh lift with matching lifters, and the comp cam springs rec for that cam. heads have been gone over and hardened seats put in. and just for future reference i have the non adjustable rocker arms. now that we know the equipment lets hear the story. bought it off craigslist. came with two motors. the original 352 and the 360 pulled from a 73 f250 i think from what i can tell. installed bigger motor cuz what gear head wants the smaller motor. it had been sitting for a while so like any good grease monkey i tore it down and checked it over. thats when the new cam and all the other goodies cam in. so im putting the hog back together have everything on except the valve covers on. i decide to do a compression check. then f*&%ing Murphy shows up. first two cranks produce 40 psi. i reset the gauge and try again. nothing. my first thought is that the valves are being hung open by the hydraulic lifters. after talking to our engine guy at work he confirms that and that i need shorter push rods. so im like ok no biggy. buy that adjustable push rod deal from comp get a measurement and find the stockers are ball parking like a 1/16 to an 1/8 to long. three sets of push rods later i have no compression. has anybody ever installed this cam on their project and if so can i ask as to how long and what brand push rods you ended up using. or if anybody has a secret way for checking push rod length?

[LM14]

Basics of modifying a valvetrain.

First, you will probably need adjustable rockers. Once you start messing with the geometry, the factory settings go out the window.

Second, when messing with the push rod length checker, were you getting a pattern in the center of the valve stem? The goal is to get the rocker to move as little as possible across the valve stem during it's travel and close to center. We came to find out we gained more from having the smallest pattern on the stem moreso than the pattern in the center of the stem. It's usually just a hair off center but you can get a small pattern by messing with it. You also need to look at the angle between the valve stem and centerline of the rockers. You want as close to 90 degrees there as you can get.

My guess is you will chase your tail until you have adjustable rockers.

Also, with that lift you will need to check for valve clearance on the pistons.

SPark

[64 f100]

My guess, you might have bent some valves. Although both 352 and 360 are basically the same engine and difference is in the bore mostly. When changing cams , always check for clearance. Did you set the timing marks right for the timing chain?

Rich

[66redrocket]

timing was set to stock setting. dot to dot. and just throwing out there to expand on the head work done. new valves all around, new seats, all surfaces were planed, guides were still within spec, and the umbrella seals were replaced with the press in style. I'm not saying that it isn't a possibility, but if i bent the valves wouldn't you feel it when the motor is turned over? Like i said before I'm new to the major modification field. So if i come off a little smartassish im sorry i just like picking the brains of the guys who have done this before.

[LM14]

Won't necessarily feel a bent valve turning it over. It usually just tweaks the stem right behind the head of the valve. If you turn the engine over slowly by hand you will notice some rockers never seem to go back to normal position if you watch closely. If it's bent very much at all your rocker arm will go loose and you will have slack between the arm and the valve stem.

If you milled the heads, installed new valves, changed the cam from stock, added different rockers, changed push rods.....you will need adjustable rockers or shim the stands.

SPark

[66redrocket]

ok sooo ive looked everything over and everything seems to be ok. sooooooo could anybody recamend a good set of or a whole new rocker arm assembly. preferably iron, wanna keep this looking old school. not saying aluminum is out of the options. and that wont break the bank. i have heard of the end rockers snapping off because they are not saported by anything so a set with the beefed up stands would be great. thanks guys

[LM14]

Before doing that, try backing the rockers off and doing a leak down test. A leak down will tell you if it's leaking past the valves or rings.

SPark

[66redrocket]

ok so what we have here is a mif. mechanic induced failure. i tore the motor down all the way (was getting pissed off and wanted to inspect the rest of the lower end anyway). sooooo after ripping out of the truck, i got the timing cover off and immediately started pounding my head against the wall. timing mark on cam was at bottom. and timing mark on crank was off doing its own thing. problem was i bought the comp cam timing set with multiple key ways in the crank sprocket. when installed the marks were lined up but i neglected to realize that the key was in the wrong slot. just glad it was on my car and not a customers. now this brings me to my next question. is the 360 fe motor and interference motor or not. because i would think that the timing set was off by at least 120 degrees but nothing went smash.

[jkimbrel65]

not

[Toyz]

With the new cam, non-adjustable rockers, etc., I am not sure it will be non-interference. As Steve stated, a leak down test would be a worthy step.
Paul

[66redrocket]

i found a good machinist so im sending him everything, block, crank, heads, and am going to have him go threw and make sure everything is still straight. just waiting for time to run it all over there