FWIW--I have no issues revving to 7000k+ on mine. I don't run it that high very often, just only when I am showing off for friends. Otherwise, I am shifting at 6500. Dyno runs show that it is maxing out around 6000-6500 so no reason to run it any higher. Not bad, considering that the short block is an O'Reilly Rebuild, +0.040.
Are there any tricks to that? When I install a distributor, (provided I didn't just remove one) I turn the crank to TDC then just make sure the rotor is pointing right where I want #1 to be on the cap, but I do always end up having to move it around a bit.
What is the down side to a reduced base circle cam? If you were forced to use either a reduced base circle cam or a flat tappet cam in a car that gets used the way mind does, which would you choose?
To zero in on it, do what you're doing, but get the pointer on 12*BTC, then remove the #1 plug wire, stick a phillips screw driver in the plug end of the wire, hold it close to a ground, then with the ignition turned on, slowly rotate the distributor back and forth and watch for the spark, soon as it sparks, lock the distributor down. If you do this correctly, the ignition will be dead on whatever you align the pointer to when checked with a timing light with the engine running.
I think the downside to the reduced base circle cams is the lifters have a harder time following the cam lobes, than those with a larger base circle. I don't know how much of a difference it would make in terms of power and rpm capability, but it would be interesting to see someone do a dyno test to find out.
Heres a dyno run from messing around last weekend. I am running a reduced base cricle cam I bought 13 years ago when I first built my 347 and did a roller conversion. Now that cam is in my 89 roller block. It is a Lunati cam .500 in./ .510 exh. 284/292 duration. I need to do some carb and ignition tuning. this run was just for fun and on half tank of old 89 octane. Ive run this cam for years. In 2 different 347 builds and now the stock roller block. It has many track runs and some nitrous runs. Sill looked great when I put it in the roller block. This is actually 3 runs, very identical.
That's one of those ideas that are obvious once some smart person thinks of it and has you saying "Why didn't I think of that?" Great idea. Will it work for magnetic pickups in electronic distributors? Just wondering if the magnetic pickup needs some speed to trigger the ignition.
I've used that method before as well on mag p/u and TFI distributors. A very smart old school guy passed that method along to me years ago.:Handshake of course on TFI you have to pull the SPOUT shorting plug out.
I would definitely use a small base circle cam as opposed to a flat tappet cam considering the way the oil situation is anymore (lack of zinc and other additives). But, small base circle cams have been shown to twist and flex even when running "street" spring pressures. The problem gets worse with high performance springs. There's a reason a lot of race cams and even OEMs are now going to larger 55 mm cam cores. For the guys running small base circle roller cams, did you put a degree wheel on the motor when installing the cam and verify the cam timing events? Often you don't get the advertised lift and duration because it would make the lobe ramps too steep on the smaller radius.
Yep, static ignition timing an engine. You can often hear the coil make a snapping noise, no screwdriver needed. Had an old Delta CD ignition back in the 70s that made a constant, low squeling noise. The noise would change pitch when when the coil fired so it was easy to set by ear.
A roller cam block has taller lifter bores ('cause roller lifters are taller) with machined tops so as to not interfere with the lifter anti-rotation plates. If you run stock roller lifters on a full-sized cam in an older block with the short lifter bores the lifters oil bands can come up out of the bores and loose oil pressure. So, in an old flat tappet block your either run stock roller lifters on a small base circle cam or special shorter link bar lifters on a full size cam.
Yeah, but his actual lift and cam timing events might be all over the place adversley affecting performance.
I didnt put a degree wheel on it. Dont have the tools, or smarts for stuff like that. Figured its gonna do what its gonna do. and if its not every last horsepower available then thats fine by me cause its enough to have fun with. I figure if I get closer to 350hp at the motor on a mild cam like that then Im pretty happy. But I dont think like a racer.
