STOCK 318 roller cam vs non roller LA

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gliderider06

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I picked up a 88 TBI 318 today for the #302 heads, and tearing it apart it is a factory roller 318. The plan was to use the heads on an earlier 77 318 (that is already rebuilt). Is there any real advantage to using a roller motor vs a flat tappet hydraulic cam? Fuel milage, performance etc? This engine will be for my stock DD 87 ramcharger, that still sports factory 2bbl and manifolds. I would consider rebuilding the tbi motor and using it for the Ramcharger if it has a clear advantage than the older motor i have for it.
Thanks, Paul
 
I think roller cams are an advantage.
No break in !
No worries about current oils !
Less hassle !
Less friction !
I hear they make more power .
Im no expert though.
 
Most roller LA engines are advertised 9.2:1 compression.
 
I wouldnt figure theres much difference since both engines are basically rated the same power.

I had an 85 5th ave which is supposed to be roller and it only got 15 mpg in town.
 
I pulled the heads and the bores are great especially for an 88. No ridges that I could feel with my fingernail and still have crosshatches in the bores.
 
With roller cams, another plus is steeper ramps that open the valve faster, leave it open longer and close it faster.....roller cams kick butt.

Jeff
 
I always wondered why the LA when they knew that they were going to go to the Magnum block. Not that I know anything about big business.They had to re-tool for such a short run.I'm not complaining,they did a good job. I'm glad to have one.
 
5 years (86-ish to 91-ish) is a pretty decent run IMO.
 
The reason mopar and others went roller was due to the fact that additives were being taken out of oil, zinc, phosphorus, molybdenum, etc because these chemicals ended up destroying catalytic converters when small amounts of oil burn.

The roller cam is a great choice and has many benefits. Compared to a flat tappet hydraulic, there isn’t really much change in power you’d actually feel.
 
The reason mopar and others went roller was due to the fact that additives were being taken out of oil, zinc, phosphorus, molybdenum, etc because these chemicals ended up destroying catalytic converters when small amounts of oil burn.

The roller cam is a great choice and has many benefits. Compared to a flat tappet hydraulic, there isn’t really much change in power you’d actually feel.


With roller cams, another plus is steeper ramps that open the valve faster, leave it open longer and close it faster.....roller cams kick butt.

Jeff
 
I think i will do a clean-up of the ports, good valve job and cut .010 from the heads. Do i need to keep the rotators on the exhaust valves, or just replace with 901 springs? For the cam, i was thinking of finding a stock 360 roller cam somewhere or having one reground by Oregon cams, for the old Ramcharger. I would like to give it just a little more power than the current 318 2bbl currently in it.
 
Im hearing people say 125.00 to regrind.
I'd ask the grinder for suggestions .
No break in on a roller !!
Good luck !!
 
I think i will do a clean-up of the ports, good valve job and cut .010 from the heads. Do i need to keep the rotators on the exhaust valves, or just replace with 901 springs? For the cam, i was thinking of finding a stock 360 roller cam somewhere or having one reground by Oregon cams, for the old Ramcharger. I would like to give it just a little more power than the current 318 2bbl currently in it.
call racer brown! 125 +shipping to maryland if i remember right! tell him what you building and all and youll be much happy'er than any with shelf cam! use valve spring that match your cam!! the stock 318 cam can be reground no need for a 360 stick to send!
 
IIRC the LA 360 FTH was 252/260/112 or 111. It works great in a 318.

I think the fastest Zero to .050ramps are on the Solid mechanicals. This allows you to run a cam up to two sizes bigger , without the cylinder pressure loss, of a FTHydraulic of similar .050 timing.
For instance;
Take the ever popular 268/276/110FTH that might have 223@.050...Well in a low compression 318LA, the cylinder pressure might fall to 125@96VP..
Same 223@ .050 but a Solid, might be a 261 to as little as 252 advertised. At 252*, the results might be 133@ 108VP.
108/96~plus 12.5% improvement in low rpm performance. And 133/125~plus 6.4% improvement in cylinder pressure. In an 8/1 engine ....at best, this is very significant. And a VP of 96 is particularly weak..

The point is; a hydraulic roller with same .050 as a hydraulic FT, may put more area under the curve but may take 8 or 10 more degrees to get the .050s.And that sucks on the bottom end.
But If they are both compared from advertised, the FTH will hit the .050s about 8* sooner, and may actually edge out the roller for a fatter area under the curve.
And a mechanical FT should be a winner big time against a hydraulic roller, when compared at say .008 tappet lift.

So all in all, IMO, the only advantages to a roller, in my mind, are the near zero likelihood of flatting lobes, and the slightly less friction to drive them.But that is offset some with worry that the needles could all end up scattered throughout your engine.
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Since my FTH has gone 100,000 now, with just the regular addition of ZDDP, I'll stick with the FTs. And I really like my 230* cam; but the 276/286/110 is a heavy penalty in the fuel consumption arena. The same .050s could get me a solid of 260/267, and if I tighten it up to 106, that would get me a power-extraction event of 118.5... versus the 105 I have now... and that is a huge jump. Coupled with the loss of 10* of overlap, I'm hoping for mpgs in the mid 20USg again (with overdrive), with only a modest loss in hi-rpm power due to the loss of overlap; but with an accompanying increase in bottom end due to the earlier closing intake, and resultant ~10psi higher cylinder pressure.
Hmmmmmmmmmmmm, actually I think I'l go a lil bigger on that Solid..lol.
 
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