factory roller motors/magnum swap

[rb77413]

Couple questions about these things. Any way to tell for sure if one is a roller without opening it up? I have an 88 carb'd 318 and a 89 5.2 TBI in our 89 Ramcharger. Both of these are rollers? Allpar didnt help much cause it says the 88 should be TBI.

About the 88 Gran Fury ex-cop car. During a freeze plug replacement episode, I decided that I wanted to rid the air pump and the exh manifolds that match. Well after a bit o thinking my plan is now to swap to MPI using a spare 5.2 intake and throttle body I have, running off of megasquirt. The problem is can the roller motors be swapped to magnum heads? Are there roller lifters that will allow the magnum heads to receive oil? Or do I need to ditch the roller cam and go with a conventional cam and lifter setup? How much hassle is it to redrill the intake to match the LA heads or do you have to redrill the heads to match the magnum intake? If this has been discussed gimme a link. Thanks.

[dwc43]

You can get the lifters, but it will cost you more than it's worth. Just put a set of milled 360 heads on it and the right cam and you'll make more power that way anyways and you'll have the better valve train too.

[cageman]

He wants the magnum intake you non reading idiot.
If it is a cop car, it all ready has 360 heads, you should know that, geesh.
They are both roller motors, that is for sure, good luck on the older roller that oils through the lifters. I am unaware of any that fit the LA roller motor.
I know drilling magnum heads to fit an older intake is easy, but the other way around, I dont think that is as common.
If you have the heads and intake off of a magnum, why not just use the whole motor, unless that is all you have. And will it fit under the hood?

[rb77413]

Hope it fits under the hood. I only have the intake so since I would need to swap the whole valve train to swap heads I might hunt for a complete engine. Not my perfered way. Hoping to get it up and running sooner than that. How good is the roller valvetrain? Never heard of any issues.

Ok on another note, what is involved in ridding the roller setup? just cam lifters pushrods? I determined to have a sleeper cop car. EFI and forced induction.

[dwc43]

Not all of them are rollers, and the only way to know is to pull them. WHen I worked for the dealer, we found them either way. You can put magnum heads on it and use a crosswind or air gap with a tbi, but it's a waste of time and money. Better to just use what you have.

As for the roller drive train, we had some problems with them early on with lifter tick just like we had with the standard hydro lifters. But latter on that was fixed and they are a pretty bullet proof set up. Twice as good as the magnum/chevy set up. You can get a shaft conversion for that head, but then again, that's more money and not worth the gain when you got a head that can do the same job.

I have not swapped a roller to a non roller, (kind of going backwards there) but the problem would be the lifter bores. The roller has a taller lifter bore than the standard hydro lifter block. A flat lifter would fall all the way in the bore. That might cause a problem with push rod clearance, but I have not tried it, and most likely wont since it's a backwards step when you can just add a custom cam to the hydro roller lifters and be done with it.

[rb77413]

Hm looking like I going with a converted EFI manifold. So what are the rpm limits of the roller setup? I plan on keeping the the rollers. Who makes custom cams? Are any cams avail for these?

[dwc43]

About 6 grand or so. The same as any hrydo lifter. The lifter pumps up cause it fill with oil faster than it can dump it at higher rpms so them it acts like a solid lifter at some point. Comp Cams will make you any cam you want and make them to fit your engine specs.

[adodgemann]

I am spinning my circle tracker 68 to 72 with a hydraulic lifters. No valve float, pulls hard right on up. Ya have to how to build a engine correctly but it sure ain't rocket science.

[dwc43]

Helps to have anti pump up lifters too.

[JVMopar]

If you are trying to use a stock truck intake you'll be disapointed as they really top off after about 4,500 rpm or so. My Dakota just lays down and plays dead after about 4,200 rpm. 360 magnum, mild ported heads, all else stock.

[dwc43]

There's a mod you can make to that intake, but there's a bad trade off for it too. You can have the runners cut back on the inside of it and gain top end power, but you'll loose too much low end to make that mod worth it. Wonder if the 2bbl intake is still available from Mopar that was made to replace the beer barrel? It lost some bottom end too, compared to the stock intake.

[adodgemann]

Originally Posted by dwc43

Helps to have anti pump up lifters too.

Nope, just ran stock Mopar hydraulic lifters, not roller tho. Set at 0 lash, lifter plunger 4 thou down into lifter body cold. That way the lifter can't pump up anymore. Allready fully extended, anti pump ups are just a waste of money.

[pcrmike]

Deedub, I have done the retro swap and found no prob at all going to flatties in a roller motor. Any aftermarket roller for mope or AMC will work and have the hole. Another thing is the magnum lifters will work, and have the hole already. Use the magnum pushrods. :-) PCRMike

[dwc43]

Originally Posted by pcrmike

Deedub, I have done the retro swap and found no prob at all going to flatties in a roller motor. Any aftermarket roller for mope or AMC will work and have the hole. Another thing is the magnum lifters will work, and have the hole already. Use the magnum pushrods. :-) PCRMike

Thanks. That's good to know if I ever decide to go that way. I was afraid of the taller lifter bore getting into the push rods since the small block has such a bad push rod angle to begin with.

[pcrmike]

Nah. The last 'teen I built was a flattie in an 88 block with the spider provision, but no roller cam as it was a cop motor. 360 heads on it, and it was a factory motor. used standard pushrods. :-) PCRMike

[rb77413]

Originally Posted by pcrmike

Nah. The last 'teen I built was a flattie in an 88 block with the spider provision, but no roller cam as it was a cop motor. 360 heads on it, and it was a factory motor. used standard pushrods. :-) PCRMike

Cop motor? Thats what I'm trying to build. So just swapping to the non roller lifters for the magnum swap work just fine? No cam change? hmmm

[pcrmike]

Yes, cam change. A flat tappet cam has different profiles than a roller. You can use a roller block, like yours, with a roller cam and roller lifters, and spider, and magnum heads with magnum pushrods. You need either Magnum lifters or aftermarket direct replacements. If you choose to rum the magnum heads with a flat tappet cam, you will need MP conversion pushrods for the swap. You will want a little more cam than the factory piece for the magnum heads. :-) PCRMike

[JVMopar]

You cannot use flat tappet lifters on a roller cam. Flat tappet lifters will not rotate on a roller cam. The lifters will wear rapidly without rotation.

[pcrmike]

Besides performing like crud. :-) PCRMike

[dwc43]

Originally Posted by pcrmike

Yes, cam change. A flat tappet cam has different profiles than a roller. You can use a roller block, like yours, with a roller cam and roller lifters, and spider, and magnum heads with magnum pushrods. You need either Magnum lifters or aftermarket direct replacements. If you choose to rum the magnum heads with a flat tappet cam, you will need MP conversion pushrods for the swap. You will want a little more cam than the factory piece for the magnum heads. :-) PCRMike

Are you sure the oil holes are in the same place for magnum and non magnum roller lifters??

[pcrmike]

No. there are no holes in the non magnum lifters. You need aftermarket Mopar/AMC lifters or magnum lifters. If you mean for the oil galley, I am almost totally sure they are. I have used them before. :-) PCRMike

[dwc43]

Originally Posted by pcrmike

No. there are no holes in the non magnum lifters. You need aftermarket Mopar/AMC lifters or magnum lifters. If you mean for the oil galley, I am almost totally sure they are. I have used them before. :-) PCRMike

So you can't use the roller magnum lifter with a roller cam in an LA block then, but you can swap to the AMC lifter. Correct.

[hotroddave40]

a 4bbl motor did not come with a roller cam from the factory. It was however a roller block. Any LA or Magnum roller cam will work. Use the magnum roller lifters. Some of the later LA roller motors had the oil hole in the lifter but don't use them unless you know they have the hole.

TBI engines only came in trucks, that is why you car motor had a carb. 2bbl and TBI engines had roller cams but they all had provisions in the block for a roller. If you put magnum heads on and a roller cam then the stock magnum pushrods will fit.

[dwc43]

Originally Posted by hotroddave40

a 4bbl motor did not come with a roller cam from the factory..

That's not true. many 4bbl engines came with roller cams. All police cars had roller cams with 4bbls as a matter of fact. Some with Thermoquads and some with quadrajunks.

[pcrmike]

But don't use the early lifters with the oil-thru pushrods. :-) PCRMike

[hotroddave40]

The police cars came with either 2 or 4bbl engines. The fact is the 2bbls all had roller cams. The 4bbl motors used a roller block but not a roller cam. The 4bbl motors used the same flat tappet cam as the 360 4bbl witch was the same cam as the 340s used, exact same specs. They never had a roller cam in a 4bbl engine from the factory, police or not. Some of the LA roller lifters from the early 90s uses a roller lifter with the oil hole for the rockers even before the magnum motors came out.

As for one of the original posters questions, the only way to tell about the motor has a roller cam is to look in the motor. If it is not sludged up to much you should be able to pull a valve cover and look down through the pushrod hole and see the dog bones and or the spider to tell if it's roller or not. Also some of the rockers on later LA motors with oil through lifters had no oil hole drilled through the pushrod cup on the rocker. I have seen those rockers on 91 and 92 360s and 91 318s. My 91 dakota 318 has these type of rockers. Do not use these rockers on a lifter/pushrod set up that does not have PR oiling. They were prepairing to switch to magnums that were strictly PR oiling.

[dwc43]

Best way to check for a roller cam is to pull a pushrod out of the engine. Roller cam engines use short push rods. At least a 1/3rd or more shorter than a stock hydro cam small block.

[rb77413]

Ok so for a roller to magnum setup all I need is to use is magnum lifters on a magnum cam and make sure the rocker has the oil hole drilled. If not what style rockers do I use?

[pcrmike]

Magnums are already drilled. You can use Chevy aftermarket rockers with an upgrade stud set. ;-) PCRMike

[Tarrbabe]

Am I the only one that can tell the difference by driving the roller motors? I knew the first time. The feel and sound is totally different.
I guess I could be wrong but I knew my 80 stepside had a roller in it the first time I drove. It was confirmed when I swapped intakes.