I have been going back and fourth with this company cylinder heads intl. I purchased a reman head from them when i put in a 89 motor in my truck. the truck before was carbed and i wanted to keep it that way, i took all the smog crap off and all efi components incl the cyl head which had ports in the head for air. ordered a non smog head from the company and installed it on the motor with new gasket, torqued to spec. Also replaced lifters, rocker arms and pushrods. all from sealed power company. which i think is federal mogul. I did not replace the camshaft when i did the lifters. soaked the lifters for days in 20w 50 oil before installing. Installed all valvetrain components and pre lubed all parts with assy lube. i have bolt down rockers and i put each cyl at tdc on compression stroke and torqued to spec in 3 increments. put on rocker cover and valve cover. my clifford manifold holley carb and hooker headers. started truck up and had loud clacking then went away. assumed the lifters were just building pressure. drove around seemed fine couldnt really hear the clacking though until one night i reved it to 2500 rpm and it is loud as hell. took the valve cover off and grabing the p rod and wiggle it and rocker is loose. for the say 250 miles i put on it my rockers are showing signs of wear that you would see at an engine overhaul.

contacted cyl head company told them what i just told you and that i had the stock pushrods in which are 10.14 and those are the longest ones available you can buy without ordering custom ones. they said they never heard of any such thing before in their lives. i said since you guys ground down the valve seats could the length affect the pushrod length and make the rockers loose. they say no never. told me some bs that gas can gum up and cause my valve stems to get stuck and not move correctly or some s h it im not buyin it. i need some ideas guys. things to ck, to look for. My oil psi at start is 40, idle when hot is 20. clacking is not timing or lean. put timing at 0 still did it. took vac advance off, still did it. got an af wideband gauge and when it makes the noise my af value is at 12.1 rich. sorry about the long drawn out post but i really dont know what the problem is unless my new parts were bad from the start which i doubt??

 

lol

 

I hope you find the problem. It feels like a kick in the stomach when something like that happens.

While researching an article about the 300, I came across something that might interest you. Ford changed valve lengths in IIRC 1984. Did your company install the correct length valves? If shorter valves were installed, then that might explain why the rockers are adjusting properly.

Crane Cams makes the longest p.rods w/o having custom made ones from Smith Bros. The Crane ones are 10.203". Isky makes them at 10.109", and Comp Cams at 10.136".

I know this sounds stupid, but did you order the correct year rockers for the new head?

Good luck.

 

The difference between the early 65--84, and the 85 and newer is .060"

Older =4.810

newer =4.750

 

I replaced my head on my truck when I did a p&p job on it and when I put it back on I had the same issue! Valves clacking sounded like a diesel. I went from an 86 head to a 85 head used all the push rods, rockers and valves that came with the head I pulled. I ended up getting thin washers and putting them under the nuts to shim them up just alittle to fix the problem. I had to do this on everyone of them. Hope this helps.

 

do you mean you put washers under the bolt heads where it contacts the fulcrums?? i have bolt down rockers i dont know if you have studs or not? thats weird why it does that though. the company i got them from still swears its new parts bad and not their problem. they want me to take it off pay to ship it back to them so they can look it over and see if somethings wrong. haha yaa right. there going to recieve it and nvr take it out of the box and call me and say nope nothins wrong. im not wastin my money

one way or the other i'll get it figured out, with your guys input

 

cool guy where did you put these shims?? and what does IIRC mean

 

I have pediatal mount rockers. You put the washer on after you put the rocker on and then the little fulcrum thing then the washer and nut. It gives it just alittle more push on the rocker arm.

 

darn. okay back to the drawing board with this one. any other inputs

 

update> talked to cyl head company today, they are actually very helpful turns out. he is confused as i am with it and was naming off things to try which i tried, but anyway he say to drain the oil put 20w 50 in her and start it up and see if it goes away, hes thinkin maybe the bottom end is going, I dont know at this point i'll try whatever but if my bottom end was that loud at 2500 rpm, one would think i hear it all the time no matter what rpm. Its def not a knocking noise. I know what a spun rod bearing and main bearing sound like and this isnt it.

 

after you toque the rockers down, you pry them all the way back (lifters collapsed) and check valve stem clearance. This will tell you if the pushrods are too short or there is a mixup in parts used.

 

update:

today made my own homemade leak down tester, put #1 cyl at tdc on compression stroke, put about 65 75 psi down there and id say about 65 75 psi came shootin right outta the hole where the oil filler cap goes. Bad rings, cracked rings or piston, maybe that noise now at high rpm is from rod bearing or something else. what do you guys think. that much psi isnt too much is it. either way it still should hold air psi. did a compression ck with the oil cap off and choke wide open on carb. Got 90 on cyl 1. did it with choke closed got 120. dont understand why that makes a difference because when i did the leakdown there was no air coming out of the carb just the oil filler cap. i dont suspect there is a burnt valve or anything?? what do you guys think, rebuild time?

 

and YES im absolutley sure both valves were closed at tdc on compression stroke when i did the leakdown