Stoked engines and small base circle cam...explain?
01-07-2003, 04:15 PM
#1
Melting Slicks
Thread Starter
Stoked engines and small base circle cam...explain?
I know this is for piston/rod clearence but does this mean that one can not use a cam off a an unstroked 350?
Thanks
Thanks
01-07-2003, 04:21 PM
#2
Re: Stoked engines and small base circle cam...explain? (KJL)
From what I was able to determine while building my 383, the small base circle cam is for longer strokes where clearance to the rod is a problem. I thhink it is cheaper to find another rod. When you use a small base circle cam, you are required to use and extra tall lifter, and they are expensive. None of the vendors said this outright, but when putting together a parts list, that is what I came up with every time.
Somebody correct me if Im wrong.
Chris
Somebody correct me if Im wrong.
Chris
01-07-2003, 05:21 PM
#3
CFOT Attention Whore
Re: Stoked engines and small base circle cam...explain? (71roadster)
chris, i'm not going to disagree with you but i just had a question. could you have used a longer pushrod instead? i see them advertised in summit and jegs all the time but i thought they were for different rocker set ups. maybe they're for just such an instance (?).
01-07-2003, 08:09 PM
#4
Re: Stoked engines and small base circle cam...explain? (KJL)
Small base circle cams do not require special lifters. The small base circle cam is approx. .080 to .180 smaller than a standard base circle cam (this varys by manufacturer)
A small base circle cam is required for large stroke motors to gain connecting rod to cam lobe clearence. The rod will try to hit the cam lobe at the area of the head of the rod bolt. On a small block a standard base circle cam will clear most rods up to a 3.800 stroke (but should always be checked). Over 3.800 stroke will require a "stroker" rod that uses rod bolts that screw into the rod body from the cap as opposed to a bolt/nut set-up as was used by the factory, or a small base circle cam, or a combination of both.
If you are building a 383 (3.75 stroke) a standard base circle cam should work fine, but as with every thing else, it should be checked for clearence.
A longer push rod will make up the difference on a small base circle cam.
[Modified by Pete79L82, 7:11 PM 1/7/2003]
A small base circle cam is required for large stroke motors to gain connecting rod to cam lobe clearence. The rod will try to hit the cam lobe at the area of the head of the rod bolt. On a small block a standard base circle cam will clear most rods up to a 3.800 stroke (but should always be checked). Over 3.800 stroke will require a "stroker" rod that uses rod bolts that screw into the rod body from the cap as opposed to a bolt/nut set-up as was used by the factory, or a small base circle cam, or a combination of both.
If you are building a 383 (3.75 stroke) a standard base circle cam should work fine, but as with every thing else, it should be checked for clearence.
A longer push rod will make up the difference on a small base circle cam.
[Modified by Pete79L82, 7:11 PM 1/7/2003]
01-08-2003, 12:45 AM
#5
Race Director
Re: Stoked engines and small base circle cam...explain? (Pete79L82)
Thanks Pete,
I'm was trembling in my boots,.... till I read your post. I have my old Beck Racing 383 Max Velocity Plus Stroker sitting in a far away room gathering cob webs.....I also have a brand new set of AFR 210 heads Fully ported and CNC'd....with special high lift roller cam springs.....I also have a Comp Cam roller cam with the roller lifters......All sitting in their original boxes....I'm scared to go close to the thing because I heard I needed a small base roller cam....I was able to get Comp Cams to take back the large base and switch for a small base....However I'm very scared to mess this thing up, so I'm ignoring it.....I'm not sure what size push rods I'll need....or rockers?????Very frustrating when no body around with knowledge about this type of buildup.....and I really don't trust the machine shops....they want mega bucks....and I have all the components except the push rods and roller rockers....Eventually I'm going to have to build up the courage to start dismanteling, clean, prep, and re-assemble....Thanks for the good info....I'm going to order the complete forged and balanced rotating assembly from Hardcore Racing advertised in Summit Racing Catalog......Hope I don't make any mistakes and grenade this thing. :seeya Cappy
I'm was trembling in my boots,.... till I read your post. I have my old Beck Racing 383 Max Velocity Plus Stroker sitting in a far away room gathering cob webs.....I also have a brand new set of AFR 210 heads Fully ported and CNC'd....with special high lift roller cam springs.....I also have a Comp Cam roller cam with the roller lifters......All sitting in their original boxes....I'm scared to go close to the thing because I heard I needed a small base roller cam....I was able to get Comp Cams to take back the large base and switch for a small base....However I'm very scared to mess this thing up, so I'm ignoring it.....I'm not sure what size push rods I'll need....or rockers?????Very frustrating when no body around with knowledge about this type of buildup.....and I really don't trust the machine shops....they want mega bucks....and I have all the components except the push rods and roller rockers....Eventually I'm going to have to build up the courage to start dismanteling, clean, prep, and re-assemble....Thanks for the good info....I'm going to order the complete forged and balanced rotating assembly from Hardcore Racing advertised in Summit Racing Catalog......Hope I don't make any mistakes and grenade this thing. :seeya Cappy
01-08-2003, 12:48 AM
#6
Le Mans Master
Member Since: Mar 2002
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Re: Stoked engines and small base circle cam...explain? (Pete79L82)
Small base circle cams do not require special lifters. The small base circle cam is approx. .080 to .180 smaller than a standard base circle cam (this varys by manufacturer)
A small base circle cam is required for large stroke motors to gain connecting rod to cam lobe clearence. The rod will try to hit the cam lobe at the area of the head of the rod bolt. On a small block a standard base circle cam will clear most rods up to a 3.800 stroke (but should always be checked). Over 3.800 stroke will require a "stroker" rod that uses rod bolts that screw into the rod body from the cap as opposed to a bolt/nut set-up as was used by the factory, or a small base circle cam, or a combination of both.
If you are building a 383 (3.75 stroke) a standard base circle cam should work fine, but as with every thing else, it should be checked for clearence.
A longer push rod will make up the difference on a small base circle cam.
[Modified by Pete79L82, 7:11 PM 1/7/2003]
A small base circle cam is required for large stroke motors to gain connecting rod to cam lobe clearence. The rod will try to hit the cam lobe at the area of the head of the rod bolt. On a small block a standard base circle cam will clear most rods up to a 3.800 stroke (but should always be checked). Over 3.800 stroke will require a "stroker" rod that uses rod bolts that screw into the rod body from the cap as opposed to a bolt/nut set-up as was used by the factory, or a small base circle cam, or a combination of both.
If you are building a 383 (3.75 stroke) a standard base circle cam should work fine, but as with every thing else, it should be checked for clearence.
A longer push rod will make up the difference on a small base circle cam.
[Modified by Pete79L82, 7:11 PM 1/7/2003]