From what I have always heard you can use stock push rods with 1.7's. Any of you guys running EQ heads and put on 1.7's? Looking like I may have an issue with length.

 

Been running that combo for 10K. EQ heads with 1.7 non adjustables. I have .027 lifter preload. Everything has been fine on the stock cam.

I'm really very curious as to what your exact problem is. When I tried to install a cam last winter with a .518 total lift (using the 1.7 rockers) in my 5.2 engine, I had piston to valve clearance issues and had to pull the cam out. The clearance was .072 intake, .089 exhaust, which was too close for comfort for me. That was with the 2.02 valves, and I used the stock 6.925" pushrods.

Perhaps there is a slight difference in the heads that caused us an issue...

One more factor to consider: how thick is your head gasket? Was the block decked and/or heads milled a bit? I would assume you would not do that to a boosted build, but it can all affect pushrod length.

 

I realize I have 1.6's so a little different but I am using stock push rods

 

actually 1.6 rockers shouldn't make a bit of difference as to the length of pushrod. That's just the pivot point in the valvetrain, it should not add nor decrease the needed pushrod length.

A Cam's base lobe can effect total length,
milling the heads can,
decking the engine block can,
head gasket thickness can,
valve stem length could, though you're supposed to use the correct stem length to remove this as a variable.

Milling, Decking, and thinner head gaskets require shorter pushrods.

A smaller cam base circle requires a longer pushrod. Making the base circle smaller is how some cam companies increase lift on a cam. I believe this is exactly how Hughes Engines re-grinds stock cams for some of their more mild performance cams.

Pushrod length is correct when you have .020-.040 lifter preload. To measure lifter preload, using the cylinder head's valve cover edge as a point of reference, you can scribe marks in a pushrod when there is no torque on the rocker arm, and then at the appropriate torque (21ft/lbs.) Measure the distance and is should be between .020 and .040. If not, change the pushrod length to get it there.

 

Well then even with my cam I'm using stock ones.

My builder did all that by feel. That was 1 part I watched him do. He would snug then down wiggle them a little, tighten then down a litlle more and wiggle um and then when he was fine how they felt moved to the other side. I was like umm don't you have to torque that or something? I guess doing it for that many years you gain a feel for it

 

so im confused can you run the 2.02 heads with the harlands sharps 1.7?

 

greenmachine didnt you get 1.72 adjustable or sum thing?

 

I am running EQ heads with 1.6 and stock pushrods. I have just over .020 preload.(getting longer pushrods made up in the near future) And with no problems. cant remember what thickness headgasket of hand but will find out and post it.

 

yes, you can run 1.7RR with 2.02 valves.

 

Wouldnt you be fine if you got differnt covers? Taller ones to add more clearance?