Matt Gruber

Was reading in the advice column in Hot Rod that they don't pump up like regular lifters, and can wind up well past 6000, as high as you want.
They allow a 10-15 degree bigger cam and maintain good idle and low speed driving.
Would like to hear your real world experiences :cheers:

Cookwithvette

Had a guy at the last place I worked RAVE about them. He absolutely swore by them. Said you could stick a big, nasty, go-like-stink cam in a car and have it behaive like a mild cam at low RPMs but give you the full effect at higher RPMs.

I have no first hand experience so I'll be interested in seeing what others have to say.

gkull

Matt - I had the Crane Hi - I lifters for years and 50,000 miles before it blew up. IMO all snake oil can be taken with a grain of salt.

I ran my 278 Crane power max to 7000 all the time with 355 ci and good heads, 1 3/4 hooker S/C headers, single plane intake and 750 cfm carb.

Bleed off lifters - If you really think about it are a function of motor oil weight and oil pressure. run 20W-50 and a High vol pump and they couldn't work.

Run 5W30 and a pump/motor that has under 30 psi at idle and they might do what they claim.

:troll Hey I'm running a 8.5 power valve now and like it!

rrent

I have Rhoads lifters -- the guy I bought the my '77 from had the local Corvette shop build him a motor to turn 6500 RPM and a car to out run Mustangs (this was probably 10 years ago) -- they built a nice motor with older big plug (I figure slightly higher compression) heads -and added a VBP rear end kit and 3.55 gears.

The lifters are noisy -- when I dropped it off for a tranny rebuild I forgot to tell my tranny guy -- he checked the oil twice before guessing it had pump up lifters.

I, unfortunately don't know what cam it has - it does run good and gets to pulling real hard around 3500RPM's (I've never had it to 6500 - probably never will).

With this shop built motor the lifter seem to work as advertised.

jimtreber

I ran them on a 12 to 1CR 406 with a 298 degree cam. They worked. It had a good smooth idle of 550rpm in drive. Pumped up full by 3500. The problem I had was by bleeding off so much duration on a 12 to 1 engine, the cylinder pressures went way up making it hard to start. Comp Cams ground the same cam for me with more overlap and solved the problem.

LiveandLetDrive

Is this what Compcams Pro Magnum lifters are? I know they're anti-pumpup. Anyway, I put these in along with higher pressure springs iwth my 268 cam. Stock bottom end original engine.

When I was at Heartland Park Topeka Friday, I accidentally wound it up to 6500 rpm :eek: when I had been shifting at about 5200-5300. Scared the living hell out of me, and kindof threw off the rest of the run, but no damage :)

-Chris

burners

I ran a set of Rhoad's for about 15,000 miles in the Vette with a Comp XE274 and was very pleased with them. They sounded great at idle (like a solid lifter cam) and I was getting about 15 mpg while cruising at 80 or 85 with 3.73 rear gears. It would pull just fine up to 6000. The only reason I'm not running them now is because the engine spun 3 rod bearings so it is being rebuilt. I would recommend them.

Fevre

One thing to note on comp ratios, the crane version I have states to use with eng that have comp ratios BELOW those recomended for use with the cam or you may experience low speed/rpm detonation. That being said I ran them in a 10/1 comp 383 with the comp cams XE 284 and that thing had great low end torq for having such a long duration cam. Too bad the eng ate rod bearings not long after start up.

BTW I also had heard the the variable duration lifters make noice so although I heard a faint tap on start up I attributed it to the lifters, my mistake. :(


[Modified by Fevre, 11:04 AM 9/22/2003]

Matt Gruber

Anybody have one to donate to science? i'd like to take one apart. Will glady pay postage.
Thanks.

clem zahrobsky

crane uses a looser fit plunger and rhoads machines a groove in the plunger. rhoads can do your hyd roller lifters also

Matt Gruber

clem
do they work better with 10w30 vs. 20w50?
Do they have a stiffer spring to take up the slack so they won't hammer the valves?
thanks! :chevy

clem zahrobsky

go to http://www.rhoadslifters.com/default.asp

Weird Science

I used them in a circle-track engine with vac rule. We had to pull 17" at 1000rpm. With the bleed-down lifters, I could run a longer duration cam and still be legal. They work by decreasing duration at lower rpm's.

70PurpleLS7

Just my opinion on this... wasn't it back in the late 80's early 90's they were the hot setup on the street? In every trade magazine they advertised big time (almost like BG Demons now :lol: ) Now you don't hear anything about them except for the occasional post like this one.

I thought they were almost like a patch for someone who couldn't resist but to get the biggest cam possible for their engine, it kinda tamed it down, make it more streetable.

gkull

Matt - I have a set of 16 Cranes hi-intensity lifters. I kept them in order in a marked box with my 278 cam. So I don't wan't to throw one away.

It's like anything - You would have to play with them and see what oil weight got the best vacuum curve for your motor oil temp. i used to have them with a High vol pump and 20w-50 and my oil pressure was @70 psi at anything much above idle. @ 40 psi at idle even on the hottest days. Then as thinner oil became the rage in racing 10w-40 when it was hot and 5or 10w-30 in cooler weather seemed the best.

The other poster was right about detonation problems with them

Matt Gruber

clem
thanks for the link. i read the whole thing.
They are true anti-pump up lifters for sure. :cool:
.
george
now that i've read about them i don't need to take one apart.
.
seems like a good alternative.
.
users please keep posting your comments :cheers: