I'm upgrading to a hydraulic roller after wasting half a set of OEM flat lifters (and possibly ruining my engine).
I like the spec of the XR270HR. 1.6 Pro Magnum rockers and Comp Bee Hive springs are already in use so they'll remain.
Does anyone have specific experience with selecting pushrods for a retro fit? Comp offers a 7.29" and a 7.3" length. I'd like to know in advance rather than assemble and measure because of the time invloved with shipping etc.
The combination isn't too exotic so I imagine there's a standard somewhere.

 

get a pushrod length tool.if you know what that is if not its a tool used to measure the length of the pushrods.

 

My point is that I'd like to order the cam. lifters and push rods at the same time. It's a little difficult to measure pushrod length without the cam and lifters installed in the engine.
That's why I've asked if anyone has assembled this combination before and has a ready answer.
It'll be a Comp cams XR270HR with Comp rollers.

 

When you measure, make sure to use a solid lifter.
See if you can oder both and return one.

 

I made a measuring lifter using 2 empty hydraulic lifters assembled together. Works great.

 

7.2" is the norm for a hydraulic roller. It's common though, so a local speed shop should stock them. I bought a length checker for $12 locally, then ordered my "custom length" pushrods right after that, for $80 or so

 

A couple of more questions on the upgrade.
As far as camshaft end play is concerned. What are the most practical and especially reliable ways of establishing and controling endplay in a retrofit?
Are thrust bearings behind the cam gear a necessity?
I like the idea of the Cloyes Quick Button timing cover and the Hex Adjust timing set with the thrust bearing. I just don't know if I really need it.
Any experiences?

 

Ever notice how these threads die right about when someone asks a useful tech question?

Yet, "which flowmaster for me? lololol" always gets 30 replies..

Search is becoming useless on this forum. What happened to all the guys
from 10 years ago???

-- Joe

 

When that happens, these people are free to PM me, and a few do.

 

Thanks for the invite. When (if) I get some cash for my project I'll be looking for some advice. Stick around, it may be years.

 

I've never bothered with the Hex-A-Just, though I do like the two piece covers so I can change the offset bushing if I want to later.... Thrust bearings with a button IMO should be a necessity, along with a very careful session degreeing in the cam and making sure my pushrod length is correct to keep the rocker arm where it belongs on the valve tip.... I too hate waiting for the pushrods to show up in the Big Brown Truck, but knowing the valve train geometry is correct is well worth the wait.... Just too many variables in ehe engine, deck height, cylinder head thickness, casting shift in the block itself to trust to luck in getting the pushrods right based on somebody else's setup.....

I see a bunch of folks have gone with the beehive springs instead of maching the spring pocket for bigger springs....Curious how they work out after some miles---anybody checked their spring pressure after a few thousand miles compared to the spring pressure when the heads were assembled????

 

radical, this thread died 16 months ago, which is why neither anesthes nor I posted any technical info in our responses.

 

Guess I didn't look back that far, only saw your post about threads going dead when no one replies to technical issues.....chances are someone could be interested anyway...or maybe even respond to my question about the beehive springs??????

 

oh. good points. okay, I've installed several dozen sets of beehives in my customers' engines, they hold up better than traditional springs when installed on traditional cams, but put them on lobes like COMP's XFI lobes, they need replaced after 2 years of daily driving. Ultra-agressive lobes will kill normal springs in 6 months of daily driving.

 

Thanks for the info!!! Being the geezer that I am, I still run the mechanical rollers and haven't yet stepped up to a hydraulic roller..../Everyone I talk to about the hydraulic rollers say they don't work well above 6500????? I would suppose the inherent pump up charachteristic of any hydraulic lifter would be the limiting factor?????

 

These days the LSx engines and some SB Fords are doing 7200 rpm just fine with HR, but not SBCs. You can run COMP 26918-16s on solid roller cams, as long as your valve lift doesn't exceed .600". You might find a few hundred more rpm, but no promises.

 

Hmmmm. Looks like I'd better stick with my old fashioned mechanical rollers..... Not going racing this time other then maybe a few track days or perhaps a bit of grude racing on Sat. nights at the drag strip..... but I do like to have a very aggresive street beast of an engine, seems the hydraulic rollers with the limited rpm's and valve lift probably won't fit the bill.....??????

 

Sure, you can get .630"-lift solid rollers, but the XFIs are helping guys get past .550", and compared to the .450" of the '90s, that's really good.

 

Ok, good to know!

Maybe someday I'll step up to the newer stuff, but I still like my high compression, hi-lift, high winding skinny blocks (both Chevy's and Ford's). I will have to admit that I looked long and hard at one of the new LS engines long and hard before settling on another sbc.... Hard to get away from a known setup, I guess....or maybe just too set in my ways to try some new technology?????



Thanks for the input, Atilla. Always good to hear what others are doing and the results they get with different setups....

 

Can't beat 'em for performance. But the noise, and maint is a bit much.. I was like 99% there and bailed at the last minute.

I don't rev though.

-- Joe

 

The stock LS7 lifters ( not the Caddy racing ones ) are supposed to be good for 7K and about the only thing from a LSX that will retro fit into earlier engines
Cheap also
http://www.summitracing.com/parts/NAL-12499225/

http://forums.corvetteforum.com/c4-g...7-lifters.html

 

I always run good polylocks and a stud girdle...Keeps them fairly well adjusted... Heck, after all these years running them, what would I do on Sunday afternoon if I didn't have valves to adjust??????

 

For the record gentlemen, ( and it's my old thread resurrected much to my surprise), the bee hives appears to be doing yoeman's duty on my little 350. Probably 40 000 miles on the latest reassembly. 100 1/4 mile passes all solidly in the 12's (documented). In addition to that I've logged many road trips that measure into the thousands of miles. The latest being a 5000 mile epic towing a u-haul from Toronto to Edmonton.
What I can't say is how the springs measure up scientifically. Although it still pulls to 6500 rpm without hesitation I haven't measured spring pressures since the latest assembly. I will say that the engine is coming out and going into the latest chassis I've cobbled together. That should give an opportunity to freshen things up and examine a few of the high wear items.
If there's any interest, I'll post the results
As far as push rod length and camshaft endplay goes: I followed conventional wisdom, ordered my parts and verified that they would work. So far so good.

 

Thanks for the comeback, Skinny!!!!! I would be curious to know how much the springs have lost if you should have the opportunity to check them! Also be interested to know how the rockers look after all those miles.... Oh yeah, what's the lift on the cam??? I'm too lazy to go look it up myself!!!!



Dave

 

With the 1.6 rockers the cam measures .535/.544.