Well why not just stratch the idea of thee 4-7 swap and send poor 67fitz a new roller cam. As suggested earlier the roller cam profile should have a clean slate not a roller version on a regular cam so this would be a good chance to get a custom profile out onto the first roller cam so others will be more lickely to follow after...
I'll pass this info along to my builder, shouldn't be a big issue since we're doing a complete rebuild.
Yes it is possible, we've done it in the V6's to get the rods to clear. Once again its another speculation there's no way to know unless it is tried. Dave Gramlow's cam is actually ground with a smaller base circle than the cam we were using in the engine in the shop so Dad is fairly certain his will have no issues, it'd be wonderful to know once he gets his engine going how it turns out for him. Same goes with how the cam is installed, when its retarded it hits, when its advanced it clears but barely. Until the reduced base circle idea is actually tried I'd hate to say yes it is a for sure answer but theoreticall it should work. Either way we advise checking to make sure that there are no issues.
The build may get underway this fall, or it could be delayed until next summer. My schedule is very much up in the air.
Guys lets clear the air here after talking to TA Mike and my machine shop I dont feel this is going to be a problem at all. It may cost a couple hundred more in machine work at most. Mike sorry if i got this thread moving in a negative direction
No worries, we just wanted to make sure the public was aware of a possible issue as soon as we found out about it and pass along everything we know about it and how to solve the issue.
Customer that's looking for a street engine without the worries of wiping out a cam. .544"-218', .544"-225', 112'LS Hyd roller. TA 1.60 roller rockers.
With that amount of duration it would appear that this isn't going to be a high RPM motor, so they will probably be fine with bolt style rods. I've revved my "weak" rods to 6000.
Hey all, yesterday when building another 350 that we have in the shop with a roller cam, we discovered that just like dad suspected with some cranks, the roller cam cleared the crank with plenty of room. The crank didnt require any clearancing. We have determined that if you still have the engine in the car, if you pull the cam out and look down the cam tunnel and while rotating the engine cant see any of the counterweights swing up then you should be fine. We dont want to say that this is for sure with every application but if you cant see the counterweights then that means that there shouldnt be any interference with the cam. I'd have to say that we lucked out on the first engine, if we had built this second engine first, everything would have cleared and we would have said, cool everything works! We would have eventually found out the hard way that there may be an issue when someone calls saying how their crank hit their roller cam and broke it resulting in a why did this happen? It cleared in our engine issue. At least now we know that there may be an issue and can inform customers of it.
Hey I have another announcement, turns out that the cams actually don't have the 4-7 swap. Apparently when the cam cores were being made the guy dad was working with thought that dad had told him to not do the 4-7 swap when dad actually told him to o No: That's as much as I know, I'll try to get dad on and post anything more that he might know.
Ok, I'm a bit confused now. Why did you have a cam/crankshaft clearance issue if the cores did NOT get the 4/7 swap?
Things have always been close to the cam in the 350 Buicks, but this is a new one for me also. When we had the roller cam in and it hit the cam was in at 3' retarded. When it was advanced it no longer hit. I'm going to say this was just luck that the stock cam did not hit this crankshaft. Because if the center line of the stock cam was in the same place we had the roller cam it would also hit. The other engine we just assembled did not present any trouble in this area. The crankshafts were not of the same casting number. I will see if I can get Michael to post the casting number of the crank that gave us grief. We were suppose to have received the 4-7 cam cores first and that what they thought they shipped us but that's not what happened. Not sure if we are even going to have them run the 4-7 swap cores now. Sales have not been bad on the current core.
Mike, thanks for the additional info. I guess when an engine design leaves so little room for error, things like this can happen. Bummed about the 4/7 swap mixup though. Except for my cam already being ground, I'd still have wanted a 4/7 cam if you went ahead and still did them. Can't see doing it again though $$.