will a 3.875 stroke clear the cam? thanks

 

Assuming we are talking SBC here...yes the crank will clear the cam, as long as you order a Small Base Circle Cam... a stock sized cam no,

 

with a stock cam whats the biggest stroke that will fit?
and yes i am talking SBC

 

Stock cam does not say much. The base circle of a cam is from the center line to the low point on the lobes times two. Which is the diameter. If you use a dial caliper and measure side to side of the lobe it should give you pretty close to the base circle.

If your stock cam is in the .930 or less, it's considered a small base circle cam and clearance is not a problem. But you have to check everything! I have a 4 inch stroker crank with 350 chevy size mains with big H beam 6 inch rods.

 

when i say stock cam i mean a typical cam that id order, obviously not actually stock, but regular size, not small base circle. would there be any problem with a 3.8" stroke? thanks

 

.930 or less, it's considered a small base circle cam and clearance is not a problem. But you have to check everything!

Stay away from Comp Cams

Crane cams and other vendors sell off the self small base circle cams.

I can't say enough about stay away from comp cams. The morons will lie to you every time

 

A 3.875" stroke crankshaft will definitely clear a stock sized base circle camshaft. But somehow, I don't think that is what you meant to ask. The camshaft clearance issue is between the camshaft and the connecting rods. The answer you want depends as much on the connecting rod used, as it does on the stroke of the crank.

RACE ON!!!

 

you can fit whatever size arm you want in there, provided your willing to grind on the rods. Sometimes with the right rod/base circle you can get away without grinding, mock up #5 before you balance the rotating assy.

 

Typically, stock base circle cams aren't anymore expensive. I've got a custom ground Howard's roller cam that cost the same as the ones they have in the catalogue.

 

i am running a 3.875 with 6 inch h beam eagle rods and i didnt have to clearance the rods just had to grind the block since i built a stroker 415

 

We have a Comp Cams with a small base cam (.875) inside a 468" which happens to (still) be the highest HP, N.A. Pump-Gas Small Block engine in the country (733HP @ 6900 x 640Tq. @ 5600). And we also have one of their's (.875) in an engine we still have bolted to the dyno tonight, that was tested Saturday night. First pull 800 HP on a 421 C.I. SB. with a 4150 carb no less. This one is not a Pump-Gas engine though. Don't cut them too short, but also don't rely on them to pick out your cam, we pick our own numbers. Thanks, Gary in N.Y.

 

Thats an awefully bold statement.

 

The contest has very specific rules.

I went to an race engine shop about 2 months ago. They had entered the national small block max hp contest last year and got the 4th in the nation. The winning motor had AFR 227cc heads done up by their very talented head design person. They were going back for the big block contest this summer.

Kidd performance in Twin Falls Idaho

 

I didn't realize that there was such a contest. Are 23* heads a rule? With 400+cfm heads available to anyone from a few companies and nascar heads flowing 420+, I figured 800+ was certainly possible on pump gas.

I'm not ******* anyones accomplishments, 733hp is certainly impressive. But due to the shear number of SBCs people build, it would be nearly impossible to know for sure that yours is the king on pump gas.

 

Read up on the contest. They had people traveling across the country to enter the Hot Rod dyno test. The best of the best blew motors even on the dyno for the win.

Everything down to the thin oil. I was at "kidd performance" in twin falls an the did 100's of dyno runs just to get the the best. I wish that they had done the final adjustmets on my 383 or 427 SBC's

I didn't mention his name before because Hot rod said his name. It's Tony Mamo I hope I got the last name spelling right. Tony and the team at AFR is coming out with a new line of great AFR heads that out flow any in the past.

 

Of course it's hard to know if there any higher numbers out there, but when I posted it a few months back on the Camaro/Chevelle site we got no info any of higher at that time. I've got to add something here, the engine (which by the way, happens to be in an early Vette) was delivered with the components (the headers, carb, etc. that were going on the car). We did however make some changes in the dyno room that gave us more power than what was posted. We kept those numbers back as a "cushion". I will give out that we have surpassed 750 HP on 93 (and the engine will actually drive on 89, but needs 93 to race) and that was back then on the dyno with our parts used for our own test numbers. To build this engine pricewise however, is definitley NOT for the "faint of heart". As for any AFR (Tony Mamo) heads, we'll pass for now. I had "words" with him around the time about a set of heads, BB's, I had tested here on a "back-to-back" deal with another brand, if my customer had used them he'd have been "down" some heavy numbers on his combo. We don't care how many CFM is going through a port, it's got to be the "RIGHT" number for it's intended use, not the "highest" number you can get. Thanks, Gary in N.Y.
P.S. I'd like to give an example here. We just delivered 2 engines, identical short blocks, (BB's on pump gas), the first had 741HP/662 Ft.Lbs. (375CFM @.700" thru a 360cc int. runner), the other, 732HP/706 Ft.Lbs. (375CFM @ .700" thru a 320cc int. runner). You can see by the torque that not only the CFM is important, but due to the "smaller" runner, the second engine is much more powerful. There would be no comparison in a "heads-up" race with all things being equal, due to the torque difference. The next time you ask about CFM numbers (from the mfr's.), be sure to ask "what size bore were they tested on"? You may be surprised by the answer.

 

AFR states on their site that all SBC heads are tested on a 4.060" bore.

 

That's quite contradictory to my previous phone conversations where I was told they are all tested on a 4.155" bores. This is what I'm saying about ALL mfr's. being misleading. They'll tell you there is only a
"couple" of CFM difference from a 4.030" and a 4.155". Using 3 flow-benches over here I can tell you that you'll see more than a "couple" CFM, maybe more like about 25 or better. Thanks, Gary in N.Y.

 

Just checked the website, 180 and 195 are tested on a 4.060 with 1 3/4. The 210 on up are tested on 4.125 with 1 7/8. I never noticed the discrepancy before, thanks man.