So I'm putting together a 408 stroker and I went with the hydraulic roller cam from lunati. Now the pushrods from the flat tappet are too long, which I figured would be the case. Was wondering if I'm going to need custom pushrods are is there common premade pushrods for this switch over from stock flat tappet to hydraulic roller. I have stock rocker arm ratio and a 515/530 lift.
Flat tappet to hydraulic roller, rush rod length
- Thread starter Mopar204
- Start date
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pishta
I know I'm right....
mechanical or stamped rockers? If they are stamped, youll just need to measure yours with a tool. If they are mechanical, you just need to measure yours with a tool. Sorry, there are alot of variables. You could get close enough with adjustables but stamped need to be spot on. If you want to go cheap, you can cut your ball and socket pushrods (if your running adjustables) down to size with a little pipe cutter and some grips to pull the ball tip out and press into the new cut end. Mopar used to sell a kit like this, 16 socketed pushrods and 16 press in tips.
rustycowll69
Well-Known Member
If you have access to a small lathe, and have a set of too long pushrods with separate hardened ends, you just chuck them up, one at a time, in a good, true, 3-jaw with the end you want to shorten hanging out about an inch or so and with a parting tool, you just walk it in with the cross slide or compound until you reach the stem of the hardened tip inside the pushrod tube. It will stop cutting when you reach that hardened stem. Then you just push the end back in, and repeat until you get to the length you want. Eazy, Peazy.
moper
Well-Known Member
Any of the conversion lifters will require new pushrods. You need to know the length you need that gives you the fewest threads showing under the adjuster with the right lifter preload. You have to measure this. Comp has threaded measuring pushrods or they can be made easilly enough, but you have to be able to measure down to the thousanth of an inch. Once the length is know, you can look at catalog numbers, or call a custom company (Manton or Smith Bros) and have them made.
MOPAROFFICIAL
Oogliboogli
Could be anywhere from 6.40-6.60 roughly, you need to get the adjuster in an ideal thread count above and below rocker arm and use adjustable push rod to take up the slack +.030 for the preload and the adjuster will take care of the variance. I would check the 4 corners,cylinder 1,7,2,8 and find the middle average and use that as your length.
nm9stheham
Well-Known Member
And you don't need a lathe... cut them a bit long with a hack saw, then chuck each one into a handheld drill with the cut end out. Then spin up the drill and push the cut end up to a fine grinding wheel; that will finish grind the end very smoothly and evenly and you can get an exact length. Then install your new ends.
Comp sells the one ended pushrods and separate ends if you want to make your own. My son and I did and it all worked out great. I had a detailed thread here on that procedure somewhere....took 3-4 hours.
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