Checking push rod length on 302 Ford roller

[TbucketMike]

Ok I have a Ford 302 HO out of a 95 Mustang GT so it's a roller motor with the pedastal mount roller rockers. Engine is rebuilt and pretty much stock except for an e303 cam 1.6 roller rockers and TFS upgrade valve spring kit. Engine shop set the valve height as per the cam card. I'm waiting on an adjustable push rod to get the correct length push rod but I thought I'd try checking the length with the stock push rods that came with the engine originally. I put the number 1 cylinder at TDC and both lifters are down. I put in a stock push rod for both the intake and exhaust and put on the rockers. I tightened them down by hand until I felt no play in the push rod and felt some resistence which would be zero lash. Correct? With my torque wrench set to 20ft lbs I get between 1/2 and 3/4's of a turn utnil I hit the 20ft lb's on the torque wrench. Does this sound like the stock length push rods will work? being I'm going a little past 1/2 a turn would that mean the push rods are to long or to short?

Thanks for the help!

 

[railroad]

Sounds just right. With pedestal mount rockers, people let the 20 ft lbs confuse them. If it was 25, 30 , or 35 the results would be the same. Once the fulcrum base bottoms out in the pedestal mount on the head, nothing changes. 20 ft lbs is insurance you have them tight. The number or fraction of a turn after there is no slack in the pushrod, is your preload on the lifter. Anything between getting the plunger off the snap ring and 1 turn is fine. Personally I like 1/2 turn with adj rockers. With no play in the pushrod, count the turns it takes to bottom out the pedestal mount. This will be the preload on the lifter. After the rocker is seated, it is not going to move any more, you can tighen for your 20 ft lbs now. The turns to accomplish this will not affect your lifter preload.

 

[Rogers23T]

I have built several roller 5.0 engines the Motorsport cams and 1.6 rockers are ment to be used with stock pushrods... If you go aftermarket push rods then make sure the have the same size. Dont want any valve to piston action , and you should have a min of 50 thousandths clearence between the valve and piston. You may wanna check this if you have changed pistions.
And I agree 1/2 turn gives you a few RPMS more and 3/4 is fine as well

 

[TbucketMike]

Thanks for your reply's guys!!! talked to Ford Racing tech dept today and he said the same thing as what the both of you are saying. Looks like I'll be fine with the stock pushrod lengths. I went through all 16 of the original stock pushrods that came in the motor. I cleaned and inspected them and they are all straight and none of the balls have any wear marks on them. Should I use them or just buy a new set of push rods to be on the safe side? Pistons aren't stock they are SLP hypers and have the 4 valve reliefs cut into them so I should be fine but I'll check to make sure.

 

[Mike]

Blue the tip of an intake and an exhaust valve. (Black marker can also work) Assemble everything and then roll the motor over so both valves fully open and fully close. Remove the rockers and look at the wipe pattern on the valve tips. Is it centered on the tip of the valve? If yes, then the stock pushrod is going to work just fine. If the pattern runs above center, the pushrod is a bit short. If the pattern runs below center, the pushrod is a bit long. And there is where your adjustable pushrod will come in handy.

 

[TbucketMike]

Blue the tip of an intake and an exhaust valve. (Black marker can also work) Assemble everything and then roll the motor over so both valves fully open and fully close. Remove the rockers and look at the wipe pattern on the valve tips. Is it centered on the tip of the valve? If yes, then the stock pushrod is going to work just fine. If the pattern runs above center, the pushrod is a bit short. If the pattern runs below center, the pushrod is a bit long. And there is where your adjustable pushrod will come in handy.

Thanks for the help Mike! I did what you said and used a black marker and colored in the tip of the valve. I then rotated the engine a few times so that the valves cycled a couple times and then I pulled the rockers. Both the intake and the exhaust were right in the middle!! For some reason though on the intake side the mark was more faint but it was still in the middle. I had a hard time trying to take a picture of this but here is a picture which mainly shows the exhaust valve. Like I said the intake was right in the middle also but the mark wasn't as difined like it was on the exhaust.

 

[Mike]

That all looks good to me.