checking pushrod length

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texas360

texas360

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I'm building a 360 with stock bottom end, Hughes whiplash hydraulic cam with sidewinder aluminum heads.. fel pro 1008 head gasket(0.039 thickness).. i have stock stamped rockers or a choice of 273 adjustable rockers.. i need to find correct pushrod height as I'm unsure if stock pushrods will work anymore... I'm new to this and i haven't really messed with adjustable rockers much.. i have both comp adjustable push rod checkers...ball to ball and cup to ball from 6.800-7.800 length... any tips or tricks to make sure i do this correctly?
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I would set the rockers adjusters to be even in the rocker (equal threads showing on either side of the rocker) and then set your pushrod to have the correct lifter preload. IMO this is just how I would do it and I feel like it gives you a good amount of adjustability.
 
The 273 style rockers should have 1 - 1 1/2 threads below the rocker when adjusted....
 
Measure with the intake off so you can see the lifter cup depress the desired amount.

Measure at 1,2,7,8 cyl...Back side of the lobe/closed and adjust till the lifter cup is about .030-.040 depressed...lock it, measure it, order them.
 
If you need to order push rods. Call Don at OE push rods. He is a Mopar guy. Don't let the name fool you. They make 80% of the push rods for all the big companies. If you ask nice he will throw in a couple of spares. His price is way better than the big supply shops. No names mentioned. They will make any length you want. Home - OE Push Rods - Manufacturer & Distributor
 
72Dart6pack said:
If you need to order push rods. Call Don at OE push rods. He is a Mopar guy. Don't let the name fool you. They make 80% of the push rods for all the big companies. If you ask nice he will throw in a couple of spares. His price is way better than the big supply shops. No names mentioned. They will make any length you want. Home - OE Push Rods - Manufacturer & Distributor
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When we built Eddie's 340, we used OE pushrods and they were great... They made the parts to our drawing and had them to us in a few days cheaper than most of the full sets available today....

I recommend OE Pushrods also... :thumbsup:
 
I have a set of OEM pushrods 7.50 in length. Send me your email & I'll send pictures.

Bill S.
 
You might want to take your email address off, it's better to PM info like that,
 
Here is what I figure for non adjustables shaft rockers.

With cam on base circle
Screw adjustable pushrod checker out till Snug against rocker.

Tool is 6.800
15 turns @ 0.050 turns
Add 0.025 for preload of hydraulic lifters

Equals 7.575 so rounded up to 7.600 for non adjustable shaft rockers.

Still trying to figure out the 273 adjustable shaft rockers.
 
Order a couple checking pushrods from Smith Bros or Manton. They're cheap and will allow you to do a professional job of measuring. Fast and accurate.
 
He's already got a checker. Chuck it in there with 273 rockers, crank down the adjuster to show 1-2 threads under rocker and then adjust the checker to depress the plunger .090 into the lifter to set your preload for Hughes cam and iron/AL combo. .090 is almost 2 turns of a rocker adjuster. So you can loosen the rocker 2 turns (from 1.5-2 threads showing) and then you adjust to get checker to touch lifter then crank the adjuster 1.8 turn in. Now your at .090 preload with your 1.5-2 threads showing. Measure the checker for the correct pushrod length and order. you can do the same with the stamped rockers, you just need to add the preload to the adjustable pushrod checker. Careful how you order ball and cup. Sometimes they say end to end, sometimes its end to cup seat.
 
mbaird said:
Really ? How much ?
I would think if my block has been squared and the heads decked they should be within .001
Click to expand...

If you're block was squared it's probably fine, but the OP's block might not have been (he did say he's using a 'stock bottom end.' I'd have to look through my notes, but when I put a set of heads and cam in my 340, the decks were far from square from the factory.

The difference was enough to warrant some additional math when ordering push rods to ensure the oiling holes/grooves on my PRW rockers were exposed and functioning properly on all cylinders. Just something to keep in mind. Never assume the deck is squared - it's always good to check.
 
here is what i came up with for the adjustable 273 with Hughes hydraulic cam
6800 length pushrod collapsed
8 turns out @ 0.050 plus 6.800 equals 7.2
plus Hughes lifter preload of 0.090 plus 7.2 equals 7.29
minus 0.150 for cup gives me total length of 7.14

does this seem correct...i found proform pushrods 66417c with length of 7.190.. these should work
 
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I just went thru this process with my motor. When calling OE Pushrods you might not get hold of them the first time. But it is definitely worth it when you do. My set were approximately $40 plus shipping. Price from Delta Cams in Tacoma, WA $120+
 
Always buy a few extra. Don thru in 2 extra for me no charge. If they are making a set? 2 extra is no biggie vs having to reset up to make the one you bent down the road 2 yrs from now. I actually took a tour of the shop. Nice place. Don knows his stuff. Don't be afraid to ask questions. He is a die hard Mopar guy. He will save you a ton of money. You will be shocked as to who he supplys pushrods for. Let him tell you.
 
you might watch the utube vid "pushrod geometry for engines. 12 minutes & very good on pushrod length for getting the most area under the curve. EDIT more geared toward stud mounted rockers but I was impressed with it
 
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I finally go it checked and checked. Turned out to be 7.389 length end to end.
 
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