SBC rod to cam clearance

[AA Performance]

Hey guys, building a 430ci SBC using SHP block, Scat 4.00" stroke, Scat stroker H beam rods and a solid roller in the 260 / 268 with around .420" lobes. Just wondering what the largest base circle cam I will get away with? Would be nice if anything larger than a .900" will fit.

[Baprace]

I just did a 422 shp with 3.875 stroke Scat rods / crank etc. and standard 242* x 246* X 110* HR cam diameter , don't remember cam lobe lift , customer picked it out , it was a Comp Cam , my crank / cam clearance was just a tad over .050 .

[racear2865]

Just make sure u get stroker rods. Some move the bolt to get more clearance
]reed

[Baprace]

I used the stroker connecting rod from Scat , it fit perfect.

[AA Performance]

Are you guys telling me you used a standard base circle cam with a 4.00" stroke ?

[Baprace]

Are you guys telling me you used a standard base circle cam with a 4.00" stroke ?

AA Performance , I used 3.875 Stroke ( 422 ci ) with a standard cam , I will double check on cam size Monday when I go back to work , but I am almost positive it was standard diameter. Customer supplied the cam , the original build was 406 ci which used 3.750 stroke. and we just used the cam again.

[cgarb]

I seriously doubt you will get away with a standard base circle even with stroker clearance rods. I guy I know built a 434 with scat h beams and a small base circle cam and they hit. He ended up buying the Callies ultra XD rods with the canted bolts for cam clearance. After using those rods he has a ton of room now.

[Walter R. Malik]

Just for conversation ... I have a 401 with a +.040", 350 block and a 3.910" stroke having a 2" journal with Scat stroker rods which clears with a 1.080" base circle roller camshaft.
A true small base circle cam is said to be .900" so, a "small base circle" is not necessary in a lot of situations for having cam to rod clearance.

It is one of Mike's solid roller cams and it certainly works well.

[AA Performance]

Just curious if any one has compared the difference between the Scat standard H beam and there stroker H beams as far as cam clearance goes? Are they using shorter bolts or different shape on the rods or both? How much clearance do they actually gain?

[Walter R. Malik]

Just curious if any one has compared the difference between the Scat standard H beam and there stroker H beams as far as cam clearance goes? Are they using shorter bolts or different shape on the rods or both? How much clearance do they actually gain?

BOTH ... shorter bolts, (smaller diameter in some situations), and a different big end shape.

[Gregory]

Check out Molnars’s stroker clearances rods. You may want to call them and give them your crank/cam specs and see what their
CAD system says.
I chose to go with Honda rod journals (1.888) so I could go with a BBC cam core. With a 1.060 BC and .440 lobe lift I have right at .050
clearance.

[Gregory]

I should have added that I have a 3.75 stroke

[Tom68]

Reading ''shorter bolts'' reminded me of this image.

Screenshot_20240226_124427_Chrome.jpg

[54chevkiwi]

I had a 1.050 base circle and it hit with 6" Callie's rods and 3.875 stroke

[Baprace]

AA Performance , the cam I used was Comp 08443-8 242* x 248* x 110* x .540 x .560 with the Scat stroker connecting rods