I have the 268H in my 1970 500 and i would not recommend. I have had nothing but problems with valves and push rods bending. I personally didn't build the motor though so maybe it was something done wrong. The motor did have the comp cams dual valve springs also. I ended up rebuilding the head with stock springs and it seemed to help with the issue but I ended up having piston rod bearing failure by that point.
Thanks for the insight. I am running stock single springs, as I felt the double springs are overkill for what this is for. Haven't decided whether to install straight up or 4° advanced to keep the torque low. I wanted to go smaller on the cam, but the 268 was all I could find available.
There's NO reason that cam should have caused you all those problems. Zero. If all that happened to you, someone fucked up the head job badly, and that's what did it. The valve guides were probably way too tight.
Either spring preload was incorrect, or if the cam bearings were replaced, the holes were not positioned correctly starving your bottom end of oil. Remember that Caddys are Camshaft priority fed. Machine shops not familiar with cad engines stick it in without checking thinking they can blame aftermarket parts.. Beware.
@@atobautomotiveChris at CadCo recommends installing timing at 0° as their cams have timing in them. If you choose to adv/retard timing make sure its degreed and spring preload is correct as the pre load will affect camshaft events. Mr. Vizard covers this well too.
Plasti-gage is a joke, and I wouldn't use it on a 3h.p. Briggs&Stratton lawn mower engine. To verify bearing clearance with ANY amount of accuracy, get yourself a micrometer and a dial bore guage. Period.. The tools aren't even that expensive today, so there's NO excuse not to. Don't even bother with Plasti-gage, you might as well not even waste your time with it, and just drop the crank right in and pray.
Junk valvetrain Expensive parts Ugly engine Heavy rotating assembly Grenade rods Cast everything Chevy tork converter won't work w o drilling flexplate Heads need major porting Won't make power at higher rpms Won't work with chevy trans Tons of bolts in timing cover Distributor Won't fit under hood No holley carb bolt pattern Intake flows up hill No 4 bolt main Hard to get performance parts 4 Bloodviking engine master
If you replace everything except the block it's a decent motor
look into the VT23121. Its the most torgue that you can get at low rpm for caddy builds..
I was the cad guy in the 1980s I started
I have the 268H in my 1970 500 and i would not recommend. I have had nothing but problems with valves and push rods bending. I personally didn't build the motor though so maybe it was something done wrong. The motor did have the comp cams dual valve springs also. I ended up rebuilding the head with stock springs and it seemed to help with the issue but I ended up having piston rod bearing failure by that point.
Thanks for the insight. I am running stock single springs, as I felt the double springs are overkill for what this is for. Haven't decided whether to install straight up or 4° advanced to keep the torque low. I wanted to go smaller on the cam, but the 268 was all I could find available.
There's NO reason that cam should have caused you all those problems. Zero.
If all that happened to you, someone fucked up the head job badly, and that's what did it. The valve guides were probably way too tight.
I dont like to put anyone down for builds BUT. Cant blame a cam shaft for that 1.. Can blame the builder..
Either spring preload was incorrect, or if the cam bearings were replaced, the holes were not positioned correctly starving your bottom end of oil. Remember that Caddys are Camshaft priority fed. Machine shops not familiar with cad engines stick it in without checking thinking they can blame aftermarket parts.. Beware.
@@atobautomotiveChris at CadCo recommends installing timing at 0° as their cams have timing in them. If you choose to adv/retard timing make sure its degreed and spring preload is correct as the pre load will affect camshaft events. Mr. Vizard covers this well too.
The older ones won't run on pump gas
5his guy is an amature
Plasti-gage is a joke, and I wouldn't use it on a 3h.p. Briggs&Stratton lawn mower engine.
To verify bearing clearance with ANY amount of accuracy, get yourself a micrometer and a dial bore guage.
Period..
The tools aren't even that expensive today, so there's NO excuse not to.
Don't even bother with Plasti-gage, you might as well not even waste your time with it, and just drop the crank right in and pray.
Agreed. Plasti gages are good at best for go-no go and thats it. For rebuilding mic and bore gauge is king.
Sorry but as being a machinist I can point out so many wrong things you're doing I'm not even going to try.
These engines lose oil prime too
The dreaded cad 500
And they like to over heat
I worked on these st upid engines for 20 years. They suck
Junk valvetrain
Expensive parts
Ugly engine
Heavy rotating assembly
Grenade rods
Cast everything
Chevy tork converter won't work w o drilling flexplate
Heads need major porting
Won't make power at higher rpms
Won't work with chevy trans
Tons of bolts in timing cover
Distributor Won't fit under hood
No holley carb bolt pattern
Intake flows up hill
No 4 bolt main
Hard to get performance parts 4
Bloodviking engine master