Camshaft question

Just disassembled an old flat head *** big valves - .100 over piston on an ARC rod - adjustable gear cam - stock crank
Question:
cam is engraved - ISKY #21 MARCO
Does anyone have any info on what the cam is - lift, duration, valve lash, target RPM, timing
Any info would be appreciated
Thanks
 
Just disassembled an old flat head *** big valves - .100 over piston on an ARC rod - adjustable gear cam - stock crank
Question:
cam is engraved - ISKY #21 MARCO
Does anyone have any info on what the cam is - lift, duration, valve lash, target RPM, timing
Any info would be appreciated
Thanks
Just call Tim and ask him directly.
For lift, just measure the base circle and subtract from the heel to toe measurement.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
The ISKY #21 is .445 Lift 270 @ .050 Duration..... WOW!!!!

how to get.... valve train to deal with that... SPRINGS???? tappets are going to go WAAAAAY UP in their lifter bores... so MASSIVE CUTTING will be needed there.... welding of lifter boss since will be cutting away... ~1/4 of the lifter boss. billet tappets since stock ones wont be able to deal with that... right?

anyone got pix of what the welding looks like on something like that... and how much of lifter boss have to cut out? springs? where to get them... that wont coil bind? and of course hefty cutting of valve pockets in head... a LOT?

how much lift can the average Briggs 5 HP accept before have to start cutting lifter boss. how much lift can stock springs take? shame to open a motor up/refresh it w/o the ... biggest cam can fit in the motor... without radical machining $$$$$.
 
Not an Isky, but a Dyno 126.
 

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Welding and lifter bore chamfering will be required if you run a slapper cam or anything larger than stock lift with stock springs.
If you use double valve springs and auto-style retainers, welding is not necessary.
If you use anything higher than .315" lift, backfacing of the lifter bores is necessary (as shown in Skidude's photo.)


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Welding and lifter bore chamfering will be required if you run a slapper cam or anything larger than stock lift with stock springs.
If you use double valve springs and auto-style retainers, welding is not necessary.
If you use anything higher than .315" lift, backfacing of the lifter bores is necessary (as shown in Skidude's photo.)


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
What does back facing like that do exactly and is there a certain depth?
 
^.
Around .315" lift, the valve will hit the underside of the cylinder head.
Even for .233" lift WKA legal slapper cams, we chamfer the lifter bores to keep the lifter from bottoming and breaking the lifter bores. Anything bigger lift, will generally get the lifter bores cut back for additional clearance.
 
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