What length pushrods? help!
- Thread starter Sirone
- Start date
DDSTANG94
New Member
the only correct way is to measure, any other way would be a guess or assumption based on someones Elses setup.
Stanger007
Founding Member
I'd measure them and get it right the first time.
When I swapped my heads I was going to get 6.700 since I had found a couple other guys that used that length but I decided to measure and turns out I needed 6.500 -- 6.700 would have been a bit too long.
Wes
When I swapped my heads I was going to get 6.700 since I had found a couple other guys that used that length but I decided to measure and turns out I needed 6.500 -- 6.700 would have been a bit too long.
Wes
95Vert
New Member
Stanger, where did you get your pushrods? After you checked them, how exactly did you go about measuring them? I've been told that different companies have different ways of measuring, I'm just trying to get an idea.
thanks
thanks
95Vert
New Member
Stanger007
Founding Member
I got my pushrods ordered locally from a performance shop. Summitracing.com would have been my second choice.
I used the CompCams adjustable pushrod to do the checking. Summit carries the Trickflow brand: http://store.summitracing.com/partdetail.asp?part=TFS-9000&autoview=sku
Following CompCams instructions (and the instructions of the engine builder at the shop) I marked the valve stem tip with a sharpie. I setup the rocker like I would normally (zero lash by wiggling rocker then 1/2 turn). Then I spun the engine over a couple times by hand. Took the rocker off and looked at the sweep. You want it centered on the valve.
A longer pushrod puts the sweep closer to the exhaust, a shorter pushrod puts the sweep closer to the intake.
Once I had the sweep was correct I measured it with some dial calipers. I did this twice for both an intake and an exhaust valve just to double check it all.
Wes
I used the CompCams adjustable pushrod to do the checking. Summit carries the Trickflow brand: http://store.summitracing.com/partdetail.asp?part=TFS-9000&autoview=sku
Following CompCams instructions (and the instructions of the engine builder at the shop) I marked the valve stem tip with a sharpie. I setup the rocker like I would normally (zero lash by wiggling rocker then 1/2 turn). Then I spun the engine over a couple times by hand. Took the rocker off and looked at the sweep. You want it centered on the valve.
A longer pushrod puts the sweep closer to the exhaust, a shorter pushrod puts the sweep closer to the intake.
Once I had the sweep was correct I measured it with some dial calipers. I did this twice for both an intake and an exhaust valve just to double check it all.
Wes
95Vert
New Member
jaja, sorry Wes for making you type all of that out.
I have the TFS checker and I know how to measure them and all, but as the article says, it's best to send out the pushrod checker (secured with tape so it won't move) because different companies measure them differently.
So I guess I'm asking you, if you just measured it with the dial calipers and didn't have a problem with the ones you ordered?
I have the TFS checker and I know how to measure them and all, but as the article says, it's best to send out the pushrod checker (secured with tape so it won't move) because different companies measure them differently.
So I guess I'm asking you, if you just measured it with the dial calipers and didn't have a problem with the ones you ordered?
Stanger007
Founding Member
Not a problem with the ones I ordered, they were dead on. CompCams checker is designed to be measured with calipers, I can't vouch for the Trickflow one, however.
Wes
Wes
95Vert
New Member
I too have seen it said ...
Not everybody uses the same standard of measurement
I'd want to talk to their tech peeps before ordering :Word:
Grady
Definitely measure. Most people need a 6.7" pushrod with TFS heads, but I ended up needing a 6.75, and Wes needed 6.5, so there's just too many variables to make a guess. Different brand rocker arms that have the pushrod cups deeper in them, or are of a different design than others, possibly different brand lifters, shaved heads, decked blocks, etc. all come into play.
SQUEEZE&STROKE
New Member
Get the Hi-tech pushrod checker from Comp cams. I used theirs and had 0 problems. You count the number of turns (line to line), multiply it by .05, and add them to the size of the checker.
Heres mine.
Original Checker length=5.800
11 turns=.550
Grand total=6.350
It was DEAD on.
Heres mine.
Original Checker length=5.800
11 turns=.550
Grand total=6.350
It was DEAD on.
Stanger007
Founding Member
95Vert
New Member
I too have seen it said ...
Not everybody uses the same standard of measurement
I'd want to talk to their tech peeps before ordering :Word:
Grady
Yep, exactly what I did. He told me to just measure it with a long caliper and round to the nearest .050" and I'll be fine.
I wish I would heard of that comp cams hi tech one before I bought this one.
Now I have to get a long caliper.
Stanger007
Founding Member
I picked my calipers up at Harbor Freight for $20 on sale, they have been a great purchase. You'll be surprised how many things you use them for. 
Wes
Wes
95Vert
New Member
95Vert
New Member
So I guess what we said didn't matter?
You give up hp, tq, increase wear on rockers, and most importantly, valvetrain stability, etc, when you get the wrong pushrod. Just a heads up. MANY things make up the correct ratio, even the head gasket used!
You give up hp, tq, increase wear on rockers, and most importantly, valvetrain stability, etc, when you get the wrong pushrod. Just a heads up. MANY things make up the correct ratio, even the head gasket used!
I will take taht into consideration and will get the correct length pushrods. And just check for correct size. Thanks all.
