Roller Rocker Arm Situation

[Ronno6]

My engine is being built on an 880 factory roller block.
The factory roller cam pushrods are shorter than flat tappet pushrods, 7.2" vs 7.8" respectively.
The pushrods I have from Comp Cams are 7.205" per their specs.

My can is an LT4 Hot Cam regrind by Willhoite's Cams, so the base circle may be a tad smaller than stock.
Heads are aftermarket Brodix clones; block decked .012" and head gasket is .015: thick.
Considering all these variables, I am surprised that the pushrod length is as close to correct as it seems to be.
But, it looks as though I am headed back to the drawing board on determining the proper length.
Again, I will know more when my studs and rockers arrive.

Interesting lesson on the oil pressure cycle of the hyd. lifter. New knowledge...thanks!
I have read about a procedure in which you prime the system with oil from the sump then actuate the lifter and check the contact with the valve. That would approximate the lifter's action when the engine is running. Interesting....

 

[Ronno6]

As a matter of curiosity, I went searching for a solid roller lifter.
I can't really seem to find what I am looking for.............
Everything 'pears to be aftermarket...no OEM.
What am I missing??

 

[Blue Ox]

The factory is not going to put solid lifters in a production engine. Too much maintenance for the average consumer.

 

[Ronno6]

The factory is not going to put solid lifters in a production engine. Too much maintenance for the average consumer.

So I would have to use am aftermarket solid roller lifter to do pushrod length checks.........

Am I to believe that an aftermarket solid roller would be identical in length to a factory hydraulic roller lifter??

 

[Blue Ox]

Couldn't tell you. You'd have to check specs or get out your Vernier and measure them.

I guess if you really wanted to be particular you could take the guts out of a hydraulic lifter and make a spacer out of aluminum or similar to keep the pushrod cup at full extension for your measurements.

 

[Ronno6]

Couldn't tell you. You'd have to check specs or get out your Vernier and measure them.

I guess if you really wanted to be particular you could take the guts out of a hydraulic lifter and make a spacer out of aluminum or similar to keep the pushrod cup at full extension for your measurements.

I was just gonna offer a similar notion.........

 

[Wumbo]

Never in my life have I heard of using a solid lifter like this. I guess I've been doing it wrong for the last 25 years by just soaking the lifters in oil overnight.

 

[Backfoot100]

You're making much harder than it needs to be. Just get a pushrod checker. You use your standard lifters and a really light spring. I got a kit from Comp that had two adjustable length pushrods and two suoer light springs. Put it all together on one cylinder and rotate the engine to verify the correct geometry. The spring is light enough that it'll never compress the lifter. Adjust the length of the checker pushrod until its perfect, take it out and measure the length. Then order that length pushrod. Its super easy and I think I paid $30 or something like that for the kit.
The only thing you need to know is the approximate length of the pushrod. They only adjust so far so they come in different lengths.

 

[Ronno6]

How about one if these??? :

You must be registered for see images attach

 

[Wumbo]

How about one if these??? :

You must be registered for see images attach

I wouldn't recommend pushing that past 5500 rpms.

 

[Ronno6]

I wouldn't recommend pushing that past 5500 rpms.

Gotcha !!!
That is to say, I agree !

 

[Ronno6]

I have installed the ARP rocker arm studs.
Whereas with the PBM studs I was seeing gaps of .024" or so stud to stud,
I see a gap of about .003" with the ARP studs.
HUGE difference!

 

[Ronno6]

As Hannibal Smith used to say, "I love it when a plan comes together!"
New studs are in and rocker arms set in place (til I set pushrod length.)
There is clearance out the ***** now!
No more scraping the valve covers with the lifters!!

 

[Ronno6]

OK. Y'all who said my pushrods didn't look to be the correct length have won a morel victory.
Using the above length checker I determined my pushrods to be about.045" too shirt.
I was able to find Comp Cams pushrods in precisely the required length.
They have a 5/16" x 7.250 length. That's my 7.205" rods + .045"
They were pricey...over $100.00 everywhere except..............Amazon, $49.88 !!!
Geez those guys amaze me sometimes!

So, now we wait for parts......again!

 

[Ronno6]

Rocker arm gauge and contact patch. Kinda short,huh??

You must be registered for see images attach

You must be registered for see images attach