afr users, what happened?????

[rculjak]

Hey guys, I have come to the conclusion that I have bent my intake valves, I am running a stock bottom end with a stock cam, I installed afr 165's 1400series 61cc with a 7/16ths stud upgrade coupled with comp cams alluminum 1.7 rockers. I have no compression on most of my cylinders, what the hell happened, are the 1.7 rockers too big with the stock cam, the guys at afr told me I would have no problems, what are you guys running?

 

[PRO50SC]

Hey guys, I have come to the conclusion that I have bent my intake valves, I am running a stock bottom end with a stock cam, I installed afr 165's 1400series 61cc with a 7/16ths stud upgrade coupled with comp cams alluminum 1.7 rockers. I have no compression on most of my cylinders, what the hell happened, are the 1.7 rockers too big with the stock cam, the guys at afr told me I would have no problems, what are you guys running?

Dude, that really sucks. Glad I was able to steer you in the right direction though. How did you come up with this combo and if it would work or not?

 

[rculjak]

well I wanted to use the stock cam and I thought it would fit without problems, since I have a blower I didnt want to make more than 450 at the wheels.

 

[cardudeusa]

I don't see how you could have bent the valves. What size valves did they come with?

 

[rculjak]

they came with 190 and 160's.

 

[Badlilstang]

Did you overtiten the rockers? Did you change to the correct pushrods? If the rockers are holding open the valves you wont have compression.

 

[cardudeusa]

What year is your car, not an 86 is it? My edlebrocks have the same size valves, I'm using stock cam and stock rockers for now and they have no problems. Maby you adjusted the rockers wrong???

 

[Rick 91GT]

Did you overtiten the rockers? Did you change to the correct pushrods? If the rockers are holding open the valves you wont have compression.

That's exactly where I'd start if the combo was just put together...

 

[rculjak]

Thanks for the info guys. I am using the stock length pushrods seeing as I am using the stock cam, its a 90, using 1.7 comp cam rockers, I have done pedistol rockers before, rotate the cam until both valves are closed(pushrods at lowest point) and find zero lash and I gave it half a turn and locked the polylocks, did I do something wrong? Maybe they are not the right pushrods, would I need longer ones? Not sure how to check that stuff just went with what people reccomended.

 

[90mustangGT]

Oh that sucks, I can feel what your feeling. My first guess would have been the rockers hanging the valves open. Bent valves would have made a bad noise when your first tried to crank it. I just can't imagine what it could be. Did you do a compression test? If you have an air compressor, remove all spark plugs, close the intake at the TB and run air through one of the cylinders, if air comes out the other spark plug holes, that will be a sure indicator.

 

[rculjak]

you see, I didnt hear anything like valves bending, the car never ran it started up idled for like 20 seconds and then never started again, I wish I could figure out the proper way to set a valve train and size pushrods without towing the car to a proffesional.

 

[Rick 91GT]

http://www.turbomustangs.com/forums/attachment.php?s=&postid=189047

 

[trendkilllx]

I have a 91 with stock short block and running stud mount afr 165's with 58cc chambers, along with tfs 1.7 RR's, and tfs stage 1 cam with no clearance problems. I cant see you have any clearance issues inless its an 86 or the valvetrain is not adjusted correctly.

 

[rculjak]

Thats what I thought, I shouldnt have clearence problems with the stock cam, mind you I have the 61cc head with the 1.7's, can you guys babystep me through setting the rockers and what to do after you are at zero lash, I went half a turn.

 

[SmockDoiley]

Do a quarter turn. 1/2 is too far. As far as pushrods. Though the length should be the same since only TrickFlows really require a different size, you shouldnt use stock since your RPMS are going to be higher and your pushrods are already used. Call AFR and verify that you can use stock length though. But it sounds like you overtightened the rockers and your valves are stuck open. I had the same issue when I did my heads, but after readjusting, it fired right up.

 

[rculjak]

I bought stock length but hardened from ford motorsport for use with valve guides. I called afr but they said you have to measure, I hope I didnt bend any valves, wouldnt I hear that because I didnt hear anything.

 

[Idwitheld-1`]

did you measure the original length push rod and then measure the new length push rod? Sometimes they accidenatlly pick the wrong part in inventory and....well you know.

I bet the valves are not closing.

 

[89CopCoupe]

Are the rockers over-tightened, and when the lifters pumped up the valves were left open?

 

[rculjak]

How do you prime the lifters and is this neccessary?

 

[trendkilllx]

I don't believe you have to prime the lifters. Here's the way i Adjusted my rocker arms. I tigthend them down by hand (with lifters in the down position) until I saw the pushrods (stock lenght) start to go down, or preload the lifters. Then I turned them another 1/2 a turn, then locked them. Car runs great.