60mm Camshaft/ 2.125 Camshaft

alcohol engine
I need to buy a new block is it worth the upgrade charge to go ahead and buy the 60mm camshaft.(new cam, pushrods).
Would I be happy with the difference in performance and reliability for what the cost is.
Thoughts?
Thanks
Randy

 

You asked for thoughts so here you go, I don't have any experience with with this so just my thoughts. Unless your getting a thicker stronger cam core or using a more aggressive 60mm only lobe there wouldn't be a performance advantage. larger bearings are more friction, unless they are rollers.

I measured the lift on our 2.125 cam hemi and the lifter aren't moving as far as they should pushing against 500 pounds seat pressure. I get 1.7 intake 1.6 exhaust rocker ratio with black stands but the lifters don't move as far ( about .030 - .040 less ) with the pushrods in it, scary.

 

I am kinda hoping Chase K. will chime in here on this
as i called Crane today and was going to discuss this very same issue with him

 

http://speedtalk.com/forum/viewtopic.php?f=1&t=401

http://speedtalk.com/forum/viewtopic.php?f=1&t=21536

 

Question:

What is the stroke length? It makes a huge difference in the answer.


Noel

 

If the 60mm cam lobe is better or I really needed that much more lift and I have a 2.125 ford cam bearing can I just grind down the mains and warble it in?

 

i have both, about the only advantage is a stiffer camshaft so a litle more lift at the lifter
obviously that brings some performance,
how much is debatable but in a max effort championship contender its probably worth it I know someone last year who brought new brad blocks and brought the 54 mm cam journal type for conformity of his parts, and they is a 6.0 legal pro mod

 

Noel
The stroke is 4.150
Thanks
Randy

 

Noel
Please continue i am interested to know where in the lengths of stroke it becomes more feasible, guesing a short stroke it has more of an advantage with valve speed.

 

Stroke Length

With a 60 mm camshaft and a 4.375 crank there will be a connecting rod to camshaft interference problem. The fix is to re-leave the rod ( A notch---- not good ). A 60 mm cam and a 4.150 crank works well.
The 60 mm core is far stiffer than the 54 mm cam. The stiffer the better.

Noel

 

we run a 60mm lsm cam in our 481x and a 4.25 crank... no problem .... 60 mm cam a lot easier on the valve spring. Doc

 

60 mm

The stiffer the better.

 

60 mm

I heard someone say one day at the race track that a little bit of flex, in the valve train, was good? I do not think that is a term used in the valve train world by any one that has studied VT dynamics.
Loft is a completely different subject.
I suggest the stiffest components you can buy. The performance, reliability,and dollar savings will surprise you.

Noel

 

Hi Guys, the theoretical advantages to the 60mm journal camshafts, as opposed to the 2.125" journal camshafts, is a 42% increase in torsional strength (twisting), and a 70% increase in beam strength (deflection). Our 60mm cams are gun drilled to obtain these results, and to help reduce the weight gain. The main drawback is having to obtain .120" shorter pushrods, but Noel can handle that. Another thing to consider, is that the lobes will now have a larger circumference, so the lifter wheels have a greater distance to travel per revolution, increasing their RPM, and potential for wear. But the increase in stability should more than offset that. The more rigid, the better, for the valvetrain, and that includes rocker shafts and stands, which a lot of folks do not pay proper attention to. Thanks, Chase

 

Should the lifters be cycled out more frequently due to the increased RPM?

 

The roller lifters are primarily abused by catastrophic events: engine suddenly overreving, other valve train components failing, valve float, etc. Long term problems can also result from the lifter bores not being perpendicular to the camshaft (also loose lifter bores), taper inadvertantly ground into the lobes, and valve train flex and instability. Continue your usual maintenance inspection of the lifters to detect "hard" spots in the bearings, split needles, and for excessive radial play. Even if you don't replace the lifters back into the same cylinders, it is beneficial to keep them on the same side of the engine. In relation to the guidebars, the roller wheels on one side of the engine rotate in the opposite direction from the other bank. Even roller lifters have a break-in process during initial use, and it is advisable to keep them rotating in the same direction throughout their lifespan. Thanks, Chase

 

Chase

Do your cams have correct lobe placement for spread lifter blocks?

 

Yes, even with the .200" spread, the roller tracks will be fully on the lobes. They will not be prefectly centered, due to consideration for clearance for the lifters on the opposite bank. Thanks, Chase