Kaama,

It's true, small block checy's don't have as many problems............It's most likely because the pushrods are shorter & straight. Where as in a big block, there is more sideload (for lack of a better term) than a small block.

Truthfully, I'm surprised that crower said not to use synthetic oil. I know I spoke to dave a few years ago, and I never recall that coming up. I think I mentioned synthetic.

Anyways, I do have to say, I'm using crower solid rollers 250/252 @ .050, with .584, 596 after lash (but I've only got little mice under the hatches - lol), but I know other people who also use them in big blocks, from 500 to 1050 HP. It seems that they are easier on the valve train than comp cams, or crane ? Maybe it has to do with the ramp angles, and all that other techi-stuff, but they seem to have that figured out. Should I build any motors, small or big, I'd definitely use them.

One thing that we did not consider, from wette vette's post is that the gm engines are hydraulic rollers (or at least I believe they are). So they always have a preload on them. Maybe this would "keep the roller on the cam" ? Just food for thought.

Wette Vette: Just thinkin through this (bare with me - lol) If the roller did not actually roll, maybe it could become scored, or score the cam..............eventually causing damage........I'm not sure, like I said, just tryin to think through it ;-)

Great posts - I find this not only entertaining, but helpful to !

checy's = chevys ! (ok, when we gonna get a spellcheck :-)

Another interesting fact..............& this is no BS. When we dynoed my friend's big block this past spring, after a few pulls to break her in, we changed from plane jane 30 wt oil to mobil 1 15-50. Then we did absolutly nothing else, but the oil change, and when we made a couple of more pulls, one was 18 horse higher, and one 19.....back to back. (the motor ended up making 932 hp when all was said & done)

I know we always hear about stuff like this, but it was actually more believable when we did it

Dave Crower said not to run synthetics ?!

The person I talked to (can't remember the name, he's and old timer and is there marine specialist) at Crower said synthetics aren't a problem in a solid roller application.

I planned on switching to Royal Purple next year.

Ratchet,
Donnie and I were watching Vince K. dyno one of his prostock motors about 4 years ago and he switched from the break in stuff, which looked like paint thinner (don't remember what it was) and put in Royal Purple (noone around had heard about that stuff then) and got something like a 40 hp gain.
Theres nothing like hearing a BB chevy at 9800rpms !! What a site, I think it was only making 1280 hp , a little low for a good Prostock engine

Chuck,

I spoke to Dave a while ago, and like I said, that just didn't sound right.

If I recall I think they said stay away from synthetic during engine brake-in. I know when you use their lifter, you ARE NOT supposed to wash them. There's some break in stuff on the needle bearings in the rollers. or some chit like that !

RJ

well the synthetic oil use to cause a problem in the old days, this is what I was told, the molecule's were perfect, were regular oil they are not, they also did not have the additives in the synthetic's that they do today, So the old type synthetic oil could cause a problem with insufficient spring pressure, but would not today, I read a tech article by the man himself, mr Teague, he used regular oil in one motor and synthetic in the other, tore them down after a race, and he said the synthetic side had a slight, Slight less wear, his test showed redline the best, but he said the key to long engine life is to change the oil every 25 hours are less even with synthetic
Mark

Ratchet,
I hear what you are saying but I have a different angle. Friction between the roller and cam cause the wheel to turn. If the friction is so low with synthetic oil that the wheel slides slightly do you really think there is enough friction to score the cam or roller wheel? Interesting topic.
Craig

There's an engine builder who builds engines for a popular SBI (?) race boat that I know of and he doesn't BS me. And if I remember correctly he told me within a year ago that Dave Crower personaly told him not to use synthetics on roller cams. This engine builder knows Dave Crower very well and has done business with him for several years. They know each other personaly.

If I were using a flat tappet cam/lifters I wouldn't mind using a synthetic oil. It all supposedly has something to do with the rollers not rolling properly/correctly on the lobes thus causing damage to the needle bearings within the rollers.

Who knows, perhaps I'll have to give the synthetics a try----but I still prefer to change my oil more than once per season. Synthetic or mineral base I still believe that frequent oil changes are key and with synthetics it's going to be more expensive for sure. I'm sure they provide better lubricating properties at higher operating temps, but if my oil only gets up to about 230* tops with a mineral based oil then what weight of synthetic should I use? I must admit that one of the benefits from the synthetic that I'm seeing here are the HP gains---that's real impressive!

I'm also enjoying all the pros & cons of the feedback here.

KAAMA,
I called Amsoil when choosing what oil to run and they suggested 10W40 or 25W40. Your engines aren't to far from mine being larger, but less radical. As stated earlier I run the synthetic stuff because of the extra bearing load capabilities. My motor will probably never see 150 HRS, because I just can't leave something alone that long without wanting to try something different. (bigger and badder)

Power boat mag./teague on tech said something about roller slippage. I will try to find the article and post.

As for motor breakin they (good engine builders ) all say breakin with 40 oil dont use syn.

Royal purple, I love the stuff smells and tastes good. I have seen better milage (been testing for over a year) They claim 1-3% hp gain. Not that great 3% X 6oo=18hp=approx. 1mph. good night