Adjustable Valve Train

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Hoosier Bird

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OK, the only thing that I can think of that would require you to have an adjustable valve train would be a larger base lobe on the cam. Does anyone have one they can measure so I can see if this is right? :huh: :popcorn:
 
Hoosier Bird said:
OK, the only thing that I can think of that would require you to have an adjustable valve train would be a larger base lobe on the cam. Does anyone have one they can measure so I can see if this is right? :huh: :popcorn:
Click to expand...

Gary - I'm driving up to Valdosta, GA and picking up all of my new 440 stuff tomorrow afternoon. I'll then have access to my NIB Bob K camshaft AND I'll be in a machine shop obviously. Should be able to get any measurement you want... Can you tell me exactly what you want measured so I can get you the info that you require?

Ray
 
ACME A12 said:
[quote="Hoosier Bird":3t37hk3b]OK, the only thing that I can think of that would require you to have an adjustable valve train would be a larger base lobe on the cam. Does anyone have one they can measure so I can see if this is right? :huh: :popcorn:
Click to expand...

Gary - I'm driving up to Valdosta, GA and picking up all of my new 440 stuff tomorrow afternoon. I'll then have access to my NIB Bob K camshaft AND I'll be in a machine shop obviously. Should be able to get any measurement you want... Can you tell me exactly what you want measured so I can get you the info that you require?

Ray[/quote:3t37hk3b]
Base diameter of intake cam lobe.
 
i don't know if this will help but i measured my old MP 484 cam and got 1.245" and my Bob K cam is 1.290"
 
My Bob K cam measured 1.275" on both intake and exhaust. FYI.

Talked to Jack (my machinist) about the adjustable valvetrain and the base diameter. His thoughts:

"Every engine should have an adjustable valvetrain...regardless of camshaft...how else are you going to fine tune it...?" :D I kind of enjoyed that response; hard to argue with him... He likes adjustable pushrods (Smith Brothers) on Chrysler engines that aren't too wild (literal translation: hydraulic flat tappet), beyond that he likes the Harland Sharps for a moderate build, and the T&D rockers for a serious build.

"Bigger the cam the smaller the base diameter, assuming any deviation from stock diameter." This based on physical limitations - can't keep adding lift on some engines - the cam lobe will hit the block. Shrinking the base diameter allows the lifter to drop down in the bore further but rise to a greater height at maximum lift. The change in distance between the lifter and the rocker is then compensated for by increasing pushrod length which is why we always have to check this on custom builds.... As for the relationship between this and an adjustable valvetrain, please refer to his previous comment... :lol:

:jester:
ACME
 
ACME A12 said:
My Bob K cam measured 1.275" on both intake and exhaust. FYI.

Talked to Jack (my machinist) about the adjustable valvetrain and the base diameter. His thoughts:

"Every engine should have an adjustable valvetrain...regardless of camshaft...how else are you going to fine tune it...?" :D I kind of enjoyed that response; hard to argue with him... He likes adjustable pushrods (Smith Brothers) on Chrysler engines that aren't too wild (literal translation: hydraulic flat tappet), beyond that he likes the Harland Sharps for a moderate build, and the T&D rockers for a serious build.

"Bigger the cam the smaller the base diameter, assuming any deviation from stock diameter." This based on physical limitations - can't keep adding lift on some engines - the cam lobe will hit the block. Shrinking the base diameter allows the lifter to drop down in the bore further but rise to a greater height at maximum lift. The change in distance between the lifter and the rocker is then compensated for by increasing pushrod length which is why we always have to check this on custom builds.... As for the relationship between this and an adjustable valvetrain, please refer to his previous comment... :lol:

:jester:
ACME
Click to expand...
Looks like I need some adjustable rockers............thanks for the info :thumbsup:
 
Hoosier Bird said:
[quote="ACME A12":2p1dbdoa]My Bob K cam measured 1.275" on both intake and exhaust. FYI.

Talked to Jack (my machinist) about the adjustable valvetrain and the base diameter. His thoughts:

"Every engine should have an adjustable valvetrain...regardless of camshaft...how else are you going to fine tune it...?" :D I kind of enjoyed that response; hard to argue with him... He likes adjustable pushrods (Smith Brothers) on Chrysler engines that aren't too wild (literal translation: hydraulic flat tappet), beyond that he likes the Harland Sharps for a moderate build, and the T&D rockers for a serious build.

"Bigger the cam the smaller the base diameter, assuming any deviation from stock diameter." This based on physical limitations - can't keep adding lift on some engines - the cam lobe will hit the block. Shrinking the base diameter allows the lifter to drop down in the bore further but rise to a greater height at maximum lift. The change in distance between the lifter and the rocker is then compensated for by increasing pushrod length which is why we always have to check this on custom builds.... As for the relationship between this and an adjustable valvetrain, please refer to his previous comment... :lol:

:jester:
ACME
Click to expand...
Looks like I need some adjustable rockers............thanks for the info :thumbsup:[/quote:2p1dbdoa]

Gary - please see my response on the other thread about his camshaft recommendation for you.

If you keep the 292H - don't discount the Smith Brothers pushrod option. A lot cheaper than the rocker option and they work GREAT - I ran a set on the Swinger before I dropped the long-arm crank in it and went to the 1.6 Crane Roller Rockers... They shipped them in about a week IIRC...you just have to get a pushrod length checker and give them the desired dimension. EASY!!!

:jester:
ACME
 
ACME A12 said:
Gary - please see my response on the other thread about his camshaft recommendation for you.

If you keep the 292H - don't discount the Smith Brothers pushrod option. A lot cheaper than the rocker option and they work GREAT - I ran a set on the Swinger before I dropped the long-arm crank in it and went to the 1.6 Crane Roller Rockers... They shipped them in about a week IIRC...you just have to get a pushrod length checker and give them the desired dimension. EASY!!!

:jester:
ACME
Click to expand...
I wonder what material and ht is on the push rods.......I could make my own in a flash. Stock rockers are 1.5 aren't they?
 
Hoosier Bird said:
[quote="ACME A12":23jjh4hd]
Gary - please see my response on the other thread about his camshaft recommendation for you.

If you keep the 292H - don't discount the Smith Brothers pushrod option. A lot cheaper than the rocker option and they work GREAT - I ran a set on the Swinger before I dropped the long-arm crank in it and went to the 1.6 Crane Roller Rockers... They shipped them in about a week IIRC...you just have to get a pushrod length checker and give them the desired dimension. EASY!!!

:jester:
ACME
Click to expand...
I wonder what material and ht is on the push rods.......I could make my own in a flash. Stock rockers are 1.5 aren't they?[/quote:23jjh4hd]

You could make your own adjustable pushrods? Oh man, WE need to go into business together...You make 'em and I'll sell 'em... :lol:

Stock stamped rockers are usually around 1.42 per Bob K...hence his, ahem, "enhanced" A12 camshaft that meets the pure stock requirements when the lift is measured "at the valve"... He's a smart one... :thumbsup:

ACME
 
Chrysler used to sell a cut to length push rod set. It was pretty much cut the tube to size and press in the end.

Have any of you guys looked at the Hughes rocker arms?? They look interesting to me and the price is reasonable.
 
Big John said:
Chrysler used to sell a cut to length push rod set. It was pretty much cut the tube to size and press in the end.

Have any of you guys looked at the Hughes rocker arms?? They look interesting to me and the price is reasonable.
Click to expand...
Aluminum?
 
So, what is your technique for adjusting hydraulic cam in a Mopar. Go down until no wiggle and then tighten 3/4 turn? :huh:
 
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