annoying valvetrain tick
 

i have 1.7RR's on my GT-40 heads and after doing so i have a tick on the passenger side. i know its on the number 4 cylinder because for some reason it seemed to want 2 shims.... that was the closest i could get it.

is it possible to get a tick if they are too tight. meaning the pre-load is too much... i know it can happen if it is not enough (valve float). but this happens at all RPM's. obviously it gets faster as the RPM's climb.

what should i do? what would be the best way to adjust them? because it has 2 shims and only some of the others have 1 should i take a shim out to see if that helps? i have no idea why one cylinder would be that far out...

please help!

thanks,
adam

are u using 2 thick shims? 2 thin shims? or 1 thick and 1 thin?
is your torque clicking at 24lbs between 6 and 9 o'clock?

im trying to remember what i used, i think it was 1 thick and 1 thin. i beleive it was tightning between 3/4 and a full turn... i know it was very odd when i did it though. i went and did it like 4 times untill i thought i had it right. i guess i didnt.

any other suggestions....

thanks,
adam

anybody??

Mmmm, I have 1.7 rr's on my GT-40 heads and have always had a tick since I installed them. I have talked to others who say the same, so I just kind of passed it off as normal.

I almost hate to even post this, as I am afraid I know the answer. But, when we put in my 1.7 rr's about 3 years, the guy just installed them and said they didn't need shims. I don't know if this is right, but I trusted him. He runs a mid-8 second Mustang himself and seems to know his stuff. Hope I am not doing any damage not having any shims installed :(

you dont NEED them if the pre-load is correct. so i wouldnt worry about it.

take care,
adam

Mmmm, well how do you know if the preload is correct? We didn't test anything, we just slapped them on and he said they were good to go:confused: .

Is it possible that since at the time my engine was new and had maybe 15,000 miles on it that he knew everything would still be okay?

because the motor was new doesnt mean you wouldnt need shims, but not all need them.... go to crane cams website to see how to properly adjust them... www.cranecams.com
or you can call them.

by the way, i fixed my problem. i had one of the rockers on the exhaust valves too tight....it wasnt shutting all the way and when the combustion would hit it would smack the valve into the seat....everything is good now!


adam

To set proper preload on pedestal Mt rockers is pretty easy. Tighten the rocker bolt down by hand till its snug. Snug meaning till there's no more play between the valve stem and the roller tip. Then torque the bolts down between 18 and 24 ft/lbs. Proper torque should be achieved between 1/4 and 1 turn, but no more then one turn. When I did mine, if I could get proper preload at just under a turn I would shim it, and try to get as close to 1/4 or 1/2 turn as possible. A thick shim would represent one full turn or more. A thin shim would represent just under a full turn. It may take some time and a few try's to get everything set properly.

Just a though, but could it be an exhaust leak and not a valve train tick your hearing??? Try the rubber hose trick, and see if you can find any leaks.

Ahh, that explains a lot. I think we are good to go then, as that is the way we went about the install. They have been like that for about 3 years now with no problems. Pretty sure it is not an exhaust leak either, as I have expereinced that before. I guess it is just the normal sound of these rockers, just as others have told me.

btw, what is the rubber hose trick?

It's not really a trick, but it does work pretty trick. Just get about 3 feet of 5/8" heater hose, and use it like a one ear stethescope. Put one end to your ear, and move the other around until you find the noise. It will become much louder when you get near it. Move the hose around the exhaust ports, etc. If that's where it's coming from, you'll know.

Take care,
-Chris

thanks guys, but i fixed the problem.

take care,
adam

Well........what was it? Just out of curiosity, ya know. :D

did my post above not actually post guys? i can see it, can you? i wrote:

by the way, i fixed my problem. i had one of the rockers on the exhaust valves too tight....it wasnt shutting all the way and when the combustion would hit it would smack the valve into the seat....everything is good now!


thats how i fixed my problem... it took a little while for me to figure out but what i did was pulled the spark plug lead at the distributor cap to eliminate combustion in that cylinder. when i did that it wasnt making the tick, so i knew it had to do with combustion (the rocker being too tight).

take care,
adam

Oops, guess it was a long night at work last night. I thought......well I don't know what I thought. Now i'm going to bed!