Hydraulic Roller Lifters w/LA Block?

-

nub340

Active Member
Joined
Sep 2, 2014
Messages
37
Reaction score
3
Location
West L.A.
Does anyone here have experience with running hydraulic roller cams in a small block Mopar motor?

My 340 LA block is currently being rebuilt at my local hot rod shop. I dropped by the other day to check on things and they showed me a very strange problem they are trying to solve with my new hyd roller lifters and comp hydraulic roller cam (20-812-9).

It appears that the tops of the lifter bore castings on my block are fairly inconsistent. Some have a bit of a chamfer or bevel around the bore hole while others do not. The depth & size of the ones that do vary. The problem is that with some of the lifters, when they are at their highest lift position, the oil groove/ring in the middle of the lifter actually pokes above the top of the lifter bore a little bit. This is obviously not good. See the attached images for reference. Quick video here: [ame]https://youtu.be/ggilUawdYlk[/ame].

The shop said they've tried 4 different sets of lifters with this cam so far (Comp, Shaver, Isky and now Morel) and they all exhibit the same issue. The head engine builder there told me he's never seen this before and right now his best idea is to have the cam's base circle ground down a bit to allow the lifters to sit further down in the bore but that sounds pretty drastic and will cost as much a whole new cam.

Is this a common problem or do I just have a particularly crappy block? Does grinding the cam down sound like the best course of action for this particular issue?
 

Attachments

  • lifter-gap.jpg
    40.7 KB · Views: 1,517
  • lifter-gap2.jpg
    48.7 KB · Views: 1,911
  • lifter-gap3.jpg
    45.9 KB · Views: 2,110
Time to stick the stock-style lifters and cam in there and not dick with it; it's not worth the price of admission; the $1000 plus labor you just spent on a retrofit, you could have 3 nice magnum roller blocks. First rodeo? When you mod, you get bit sometimes.
 
I have run roller lifters in an LA block without issue. This is a 76-77 era 360 block and you will immediately see the difference in the casting around the lifters. I would say someone got handy with a grinder in your block. The roller cam in my block was from Competition Cams and was ground on a LA blank. The roller lifters are from Hughes.

pushrod%252520angle.jpg



rollerlifter01.jpg
 
I had deep chamfers in my 340. I have MRL Performance lifters and no issues at all. Hughes also has some that will work.
 
Time to stick the stock-style lifters and cam in there and not dick with it; it's not worth the price of admission; the $1000 plus labor you just spent on a retrofit, you could have 3 nice magnum roller blocks. First rodeo? When you mod, you get bit sometimes.

Thanks for the perspective Poison.

I'd be the first to tell you I have no idea what I'm doing and am just trying to learn as much as possible as I go. I suppose I can always go back to the drawing board in terms of cam but are you saying this is a known issue to you veterans or something?

I originally built this motor for drag racing over 15 years ago and it always had hydraulic flat tappets until now. This time 'round my goal is a motor for daily street driving and overall reliability in L.A. traffic. The shop that did my heads recommended this particular cam to compliment their work so that's what I went with...

I have run roller lifters in an LA block without issue. This is a 76-77 era 360 block and you will immediately see the difference in the casting around the lifters. I would say someone got handy with a grinder in your block. The roller cam in my block was from Competition Cams and was ground on a LA blank. The roller lifters are from Hughes.

Ha, yeah that's what I said. The shop swears they didn't touch the lifter bores/castings though and that they just smoothed out of the oil galley some and that the issue is with the original casting and that 70's Mopars are just notorious for having crappy/inconsistent castings.

I had deep chamfers in my 340. I have MRL Performance lifters and no issues at all. Hughes also has some that will work.

Thanks dude, I'll let them know to give those a try!
 
Our 71 casting 340 block was exactly the same way as yours, OP. The chamfers leading down into the lifter bores were very irregular; it is like the chamfer was put there at varying depths, and I surmised it is machined there to just provide some clearance at the top of the bore casting for the main lifter bore finishing tool.

For the MRL's and others, the info on the lifts of the cam that had not issues with the MRL's versus the lift that you have in this cam needs to be considered. And I thought the MRL were solid rollers, not hydraulics.....??? The Hughes lifters say they are OK with the varying chamfer heights. But I am sure the have a max lift; they give good dimensions.
 
Can you return your cam or was it a custom ground? Can you get a cam on a .900 BC, and I would double check with the engine builder if that will for sure correct the problem. Other than that, is there another cam company that makes shorter lifters where the oiling hole will stay in the bore?

Good luck!
 
sorry to say but that is why later blocks for roller lifters have taller lifter bores. I would not grind the cam for a smaller base circle, not enough lifter support at full lift, when the springs are at peak load. mopars have the big .904" diameter lifters, so they do not need rollers as much as the other chumps. and with the lifters and pushrods at different angles, the smallblock mopar likes lifter support
 
I just called Hughes to inquire about their lifters. Spoke with Dave who was familiar with the issue and said their lifters usually do the trick and are really just Morels so the ones I already have *should* work unless the size is somehow different. Their product page HERE specifically acknowledges this issue as well.

He also recommended against grinding the cam and advised that I get the bores sleeved at a good machine shop that knows Mopar if I must do something. However before doing that he recommended that I measure the gap height on each problem lifter and report back to him so he can check to see if he has anything that will work. If I actually end up needing to get my blocked sleeved it'll be the first instance in like 5 years he's heard of it. :wack:
 
You have good dimensions right there on the Hughes page; I would be measuring them all. How much valve lift do you have, BTW? How many bores have the issue? Just wondering if welding up or sleeving 1 or 2 and reboring them would be less expensive.
 
sorry to say but that is why later blocks for roller lifters have taller lifter bores. I would not grind the cam for a smaller base circle, not enough lifter support at full lift, when the springs are at peak load. mopars have the big .904" diameter lifters, so they do not need rollers as much as the other chumps. and with the lifters and pushrods at different angles, the smallblock mopar likes lifter support
If the lobes heel areas are not being ground any lower than the original cam core casting marks, I am not sure how the support is being compromised/reduced? The strength of the cam is the smallest diameter portion .... ???? 'course there could be a limit with the roller diameter that I am not aware if.
 
What a pain. I would just put flat tappets back in.
And get a 360 (or 318 ) roller cammed LA or Magnum block.
I have a 1990 360 LA roller cam and was so much more easier to deal with.

360's in 1988 to 1991 came with roller cams.
 
Hey Sledger, how do you like your roller lifter setup? Is it worth the hassle in your opinion?

You have good dimensions right there on the Hughes page; I would be measuring them all. How much valve lift do you have, BTW? How many bores have the issue? Just wondering if welding up or sleeving 1 or 2 and reboring them would be less expensive.

Cam lift: .541/.537
Full specs: 20-812-9

I stopped by the shop again today and we went over each lifter one-by-one: Only two lifters fit OK and the rest either have an obvious gap or are sketchy-close. The largest gap is the one in the photo I posted above and is a few thousandths of an inch.

If the lobes heel areas are not being ground any lower than the original cam core casting marks, I am not sure how the support is being compromised/reduced? The strength of the cam is the smallest diameter portion .... ???? 'course there could be a limit with the roller diameter that I am not aware if.

This is essentially the same logic that my engine builder was using when explaining to me why grinding is prob going to be our best option. When you consider that the core of the camshaft is smaller in diameter than the lower cam lobe, then having the cam lobe shaved down a few thousandths of an inch won't have any real impact on the strength or support of the cam; especially since I won't be running super-crazy springs or anything.
 
I had the same problem with a pre magnum 360LA roller block with magnum roller lifters and a .548 lift hyd roller cam. After a lot of measuring and consulting with the tech at comp cams the cam was ground on a .900 base circle to keep the lifters in the bores(this was before retro fit hyd roller lifters) this engine ran great and was regularly shifted at 6700 rpm. The tech told me at the time that the .900 base circle was used on small block chevy 383 strokers so the cam would clear the rotating connecting rods. At this point of your build I think the small base circle cam is the least expensive way out.
 
Our 71 casting 340 block was exactly the same way as yours, OP. The chamfers leading down into the lifter bores were very irregular; it is like the chamfer was put there at varying depths, and I surmised it is machined there to just provide some clearance at the top of the bore casting for the main lifter bore finishing tool.

For the MRL's and others, the info on the lifts of the cam that had not issues with the MRL's versus the lift that you have in this cam needs to be considered. And I thought the MRL were solid rollers, not hydraulics.....??? The Hughes lifters say they are OK with the varying chamfer heights. But I am sure the have a max lift; they give good dimensions.

My cam is 0.530" lift.

You should really just give Mike a call and see what he says.

http://www.mrlperformance.com/

Mine are hydraulic roller lifters.

 
Never trust a fart, I mean shop.

Nobody cares for your junk like you do.

X2 .. Comp Cams, no Chevy..useless.. My 408 build : 3 different phone calls,3 different " techs"... I didn't change the wants/needs/hardware description ,one bit. The best recommended came from Clay Smith, Crower ,& Howard's. As for the post : Is your machinist watching the oiling hole come out, past that ground down lifter valley? There's the big dilemma, in my opine...

Added: reference MRL,on this one: Nice video add, he knows the product, I would contact him.
 
Cam lift: .541/.537

I stopped by the shop again today and we went over each lifter one-by-one: Only two lifters fit OK and the rest either have an obvious gap or are sketchy-close. The largest gap is the one in the photo I posted above and is a few thousandths of an inch.

This is essentially the same logic that my engine builder was using when explaining to me why grinding is prob going to be our best option. When you consider that the core of the camshaft is smaller in diameter than the lower cam lobe, then having the cam lobe shaved down a few thousandths of an inch won't have any real impact on the strength or support of the cam; especially since I won't be running super-crazy springs or anything.
That is actually valve lift per the spec, not cam lift, and yes, is moderate. I can see why moderate springs will work out. I'd certainly consult with the cam mfr on the base circle, but it does not sounds like it has to be reduced too much. (And it is something I have not ever done so that is another reason to double-check!) I re-read Marco's comment on the lifter support needed with lifter to pushrod angle, and that is true, but all that angular lifter support comes from the lifter bores alone; the cam cannot contribute to that.

Did the existing lifters match up to the Hughes diagram dimensions? I would sure give them a call if they are different... but some money may have already been expended on lifters.
 
I had this exact same problem. First get MRL lifters. Next call Comp and have them lower the base circle. They lowered mine for 100 bucks.

Easy fix but cost more money. I just ordered a new cam from Lunati and they are gonna grind it with a lower base right from the start at no additional charge. Once you already find this crap out, it's much easier.

If ya decide to go solid, I have last year's Comp, already reground .681/.688, I'd almost give away.:D
 
I have a 1971 LA 340 with the same Hydraulic cam and rollers but didn't assemble yet. Oh, boy! I curious too, as to what direction nub 340 takes. I didn't know about this problem and what other members did to solve it.
 
Did the existing lifters match up to the Hughes diagram dimensions? I would sure give them a call if they are different... but some money may have already been expended on lifters.

Yeah I measured them and they're exactly the same as the ones Hughes sells.

Still leaning towards a cam grind to get out of this mess but will check out MRL first.
 
I had an issue with the lifters on my 360 LA and comp cam. Mine was a little different as on my block the bottom of the lifter came up past the oiling hole in the lifter bore. Comps first answer was to send me another set of lifters. Didnt make any difference. Then I sent cam back to have the base circle reground. They didnt go far enough. Then on the 3rd try they ground me a new cam from billet stock but still wasnt quite far enough. At this point I was very frustrated and called Mike at MRL. He assured me his lifter had a smaller roller and would reduce the total height the lifter moved up. He was correct and my problem went away. My cam had a .575 on both intake and exhaust. My lifters were solid rollers so I dont know about hydraulics but I can tell you Mike will understand your problem and will offer great advice. A super guy to talk with and very very knowledgeable about our engines!
Best of luck
Rod
 
I've heard nothing but "great fit" on these. I also heard MRL went to quite a bit of trouble bringing these to market.

Yeah if we can't get the hydraulic rollers to work then solid rollers from MRL will might be the way to go.

I had an issue with the lifters on my 360 LA and comp cam. Mine was a little different as on my block the bottom of the lifter came up past the oiling hole in the lifter bore. Comps first answer was to send me another set of lifters. Didnt make any difference. Then I sent cam back to have the base circle reground. They didnt go far enough. Then on the 3rd try they ground me a new cam from billet stock but still wasnt quite far enough. At this point I was very frustrated and called Mike at MRL. He assured me his lifter had a smaller roller and would reduce the total height the lifter moved up. He was correct and my problem went away. My cam had a .575 on both intake and exhaust. My lifters were solid rollers so I dont know about hydraulics but I can tell you Mike will understand your problem and will offer great advice. A super guy to talk with and very very knowledgeable about our engines!
Best of luck
Rod

Interesting. When you say your lifters were solid rollers, do you mean the original lifters that didn't fit before you had Comp regrind or do you mean the lifters you ended up going with from MRL? When you had your cam reground and all jazz that with Comp was that always with solid rollers or did you change it up after realizing hydraulic rollers weren't going to work well?

Either way I'll give Mike a call on Monday and see what he thinks. Thanks for the feedback!
 
-
Back
Top