pushrod length on a Gen 6 502
 

I'm trying to measure for my pushrods and having some questions. I'm using the mid lift or half lift method where I
align the center of the trunion and the center of the roller tip
to 90° of the valve stem at half the total lift.

I've concluded the the intake pushrod should be 8.850
and the exhaust 9.550. I'm just not confident with my
method.

low deck 9.785 gen 6 block, morel solid roller lifters,
crane wide body rockers 1.7. AFR 325 heads, 2.30 X 5.560
intake valves, 1.88 X 5.450 exhaust valves, Cometic .040
gaskets. Cam is a Reed

anybody setup a similar engine?

Get your self an adjustable pushrod.

Set the length close to what you think it should be.

Put some ink on the valve tip and rotate the motor and adjust pushrod length so that the roller tip only hits the center on the valve tip.

I have a set of used .080 wall pushrods for sale.

When you find out what you need, PM me and I'll see if they are the right length for you.

They are perfect and will be cheap !!

Smitty

Use the sharpie method. http://www.popularhotrodding.com:80/...variables.html RMbuilder forwarded this to me, good info.

I can't answer your question but that sounds like a cool motor. Please tell us more about it. Was it a stock 502 Mag that you modified or did you start from scratch? What did you do beside the heads/valvetrain?

Thanks

Started out a 415HP 502 that I wanted to add a M3SC procharger to. it had about 190 hrs on it so I figured
I better freshen up the engine, then it snowballed from there.

I added H beam 6.385 rods new JE blower pistons , coated
clevite bearings, AFR 325 CNC heads, ARP bolts through out.
custom cam, I had Sunset racecraft in Lubbock do all the machine work and assemble the short block.

this will be a EFI engine using a Haltech ECM.
here is a pic, oh yeah going in a 21 Daytona Jet
http://i258.photobucket.com/albums/h...g?t=1245426222

Outlaw,
I just installed 8.900" In and 9.650" Ex on std deck 454 with Dart Pro1 marine heads and Comp solid roller lifters. I used the half lift method and this is where it came out. Pattern on valve tip looks good. very narrow pattern with intakes being a little to the exhaust side of the valve tip and the exhausts are dead center.

With tall valves it is hard to get pattern exactly in the center with stud mount BBC. It is a slight trade off between narrow pattern and centered on the valve tip.

Hope this gives you some confidence that your lengths aren't way out of the norm.

Thanks Baja208, did you have your lash set while checking?
I just have a hot setting on my cam card so I checked it with zero lash and again with the Hot setting.

My pushrods are 8.600/9.450, and I used the mid-lift method, which is the correct method. The magic marker method is wrong on many levels, and shame on the manufactures for suggesting it.


Your intake seems long for some reason. The AFR head need a +.200 longer pushrod, stock 502's are something like 7.5/8.5. My heads were angle milled which alters things a bit. My friend just did a 540 with AFR's and his pusrods came in at 8.6/9.550.

You will find that the AFR heads have a small issue in terms of geometery...the intake valve sits a bit too close to the rocker stud, or vice versa. The pattern using the mid-lift will fall way outside on the stem. You will need to find a happy medium. If you want perfection, Crower makes a "back-set" rocker to bring the roller tip back on to the stem alot better.

Outlaw,

I checked mine with .012" clearance. My cam calls for .018" hot. I subtract .006" to compensate for iron block with aluminum heads when engine is cold. Clearance shouldn't make a big deal I normally only hold pushrod length to the nearest 0.050" anyway.

BTW: That is a great looking engine. Love the polished heads. What do you plan to use for valve cover breathers?

Thanks for all the replies, I'm going to check them one more
time then place an order.

Baja208 I have a set of those tall breathers that came with the covers, just waiting to get everything on before I drill the holes in the covers. As you can tell the pic was just a mock up of the parts after I painted the short block. I'll post one of the final assembly (hopefully soon)