1:20 "supposedly it throws off your valve geometry" It can, slightly, but that is easily corrected with longer pushrods. The lifter is always moving up and down in a straight line regardless of the base circle. They can also create oiling problems with hydraulic lifters, but again there are ways to correct that as well. The real issue with 'reduced base circle' cams is that they are harder on the valve train because the ramps need to be more aggressive to get the same lift and duration as a standard base circle cam. It's one reason lots of aftermarket blocks are now available with raised tunnels that will accept a cam ground on a big block diameter blank. This allows even more lift/duration with less stress on the valve train.
My 406 with 5.7 rods needed clearancing stopped dead when it first hit the cam was just turning it by hand. I just kept gridding that area until I got .080. Did that 25 years ago never had any issues that engine is still in my 64 Chevelle has a lot of miles on it.
If i'm not mistaken, eagle sells stroker clearanced rods, so does Scat. I have this same issue in a motor i build a long time ago, before that stuff was readily available. It sucks if you just clearance the rods yourself since you can't really change cams without an issue developing with clearance. LSA, duration, lift and advance/retard make it almost impossible to anticipate your clearance without taking the motor apart.
ya, why would eagle market the KIT i bought...i would have LOVED avoiding the extra work. I figured it came with the territory. It is running great at this point though.
When I built my 383 on a 010 block I used 6" stroker rods, small base hyd. roller 236/244@.050.......550/550.....110 lsa, Weisco flat tops for 10.7 to 1 and Scat 3.750 crank and did zero clearancing.
@frankscavo5170 yeah I used to mess with these a bit in the 410s ended up using the carillo rods with the profiled big end and reduced base circle cams the only way with the lobes we were using in the low cam blocks at the time.
The Eagle rods needed to be clearance on all cylinders in the block. . The cam is 114 degree base so the cam interference, on a regular/ large base circle was on cylinders 2 and 6 . Using a cam larger than the lift of .567 will mean more grinding. Since this is a turbo build and lower RPM, we just made it with the cam clearances. You will need a SMALL BASE CAMM CIRCLE if u have high lift cam for higher compression and rpm on a stroker. We are at 6,500 rpm max and 10:1 compression. And the new EAGLE crank and KING bearings clearance out a .001...tighter than I have ever seen, but the new specs are what they call for.
1:20 "supposedly it throws off your valve geometry"
It can, slightly, but that is easily corrected with longer pushrods. The lifter is always moving up and down in a straight line regardless of the base circle. They can also create oiling problems with hydraulic lifters, but again there are ways to correct that as well.
The real issue with 'reduced base circle' cams is that they are harder on the valve train because the ramps need to be more aggressive to get the same lift and duration as a standard base circle cam. It's one reason lots of aftermarket blocks are now available with raised tunnels that will accept a cam ground on a big block diameter blank. This allows even more lift/duration with less stress on the valve train.
solid analysis. old technology sbc and the larger cam base is good...works for most. running good for a year now
My 406 with 5.7 rods needed clearancing stopped dead when it first hit the cam was just turning it by hand. I just kept gridding that area until I got .080. Did that 25 years ago never had any issues that engine is still in my 64 Chevelle has a lot of miles on it.
not for the faint of heart...sometimes ya just gotta grind to make it fit
If i'm not mistaken, eagle sells stroker clearanced rods, so does Scat. I have this same issue in a motor i build a long time ago, before that stuff was readily available. It sucks if you just clearance the rods yourself since you can't really change cams without an issue developing with clearance. LSA, duration, lift and advance/retard make it almost impossible to anticipate your clearance without taking the motor apart.
ya, why would eagle market the KIT i bought...i would have LOVED avoiding the extra work. I figured it came with the territory. It is running great at this point though.
When I built my 383 on a 010 block I used 6" stroker rods, small base hyd. roller 236/244@.050.......550/550.....110 lsa, Weisco flat tops for 10.7 to 1 and Scat 3.750 crank and did zero clearancing.
scat is probably the way to go
@@frankscavo5170 I got very lucky things worked out the way they did........
Use the correct rod it will miss everything even that baby cam😅
Eagle....not quite what scat is from what I see...but too late
@frankscavo5170 yeah I used to mess with these a bit in the 410s ended up using the carillo rods with the profiled big end and reduced base circle cams the only way with the lobes we were using in the low cam blocks at the time.
Comp cams really wanted the big base cam for solid rollers...never looked at crower...there'salways a faster gun.
The Eagle rods needed to be clearance on all cylinders in the block. . The cam is 114 degree base so the cam interference, on a regular/ large base circle was on cylinders 2 and 6 . Using a cam larger than the lift of .567 will mean more grinding. Since this is a turbo build and lower RPM, we just made it with the cam clearances. You will need a SMALL BASE CAMM CIRCLE if u have high lift cam for higher compression and rpm on a stroker. We are at 6,500 rpm max and 10:1 compression. And the new EAGLE crank and KING bearings clearance out a .001...tighter than I have ever seen, but the new specs are what they call for.