[Steve C.]

"The amount of lash has no effect. It's the velocity at the lash point that hammers the valvetrain. A .030" clearance ramp doesn't have to be any harder on the valvetrain then a .010" ramp. Clearance is clearance."
Mike Jones
Jones Cam Designs

Source : https://www.speed-talk.com/forum/viewtopic.php?t=11597


( Information provided in this post does not represent any endorsement. And unless specified it is not based on personal experience and is offered for general interest only )

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[Steve C.]

And to muddy the water further regarding high pressure pin oiling on solid roller lifters. Make sure you understand the potential of the lifters not having their oil band exposed to the lifter bore feed holes 100 percent of the time under certain circumstances. I know the base circle of the cam has a impact as does the lifter oil band location and/or width for sufficient oil feed for 360 degree's of rotation.

It is up to the builder to inspect for sufficient oil feed for 360 degree's of rotation, IF DESIRED. Some suggest no issue with that situation, including the opinion of Crower when I called them years ago regarding the subject on a street application. My suggestion would be to talk to Mark at Luhn Performance on the subject.

If interested in the subject here is a Video with Crower solid roller lifters used in conjunction with a .4300" lobe lift solid roller cam in a Pontiac factory block. On the base circle the lifters edge orifice oiling hole is not exposed to the oil band. Until the lifters start to move upward the HIPPO oiling hole located within the oil band does not get 100 percent oiling.

https://www.youtube.com/watch?v=JoU_hUgq4O0&app=desktop


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[punkin]

Wow guys. Thanks very much. You have me very seriously rethinking the mechanical set up.

[Steve C.]

Side note- the information in my post number 36 here was just for general information. That is why I stated check it "IF DESIRED". Consider the untold number of people running solid roller lifters with thousands and thousands of miles on the street with that very situation and with NO reported issue with it.


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[punkin]

Thanks for the photos. Does anyone sell these already modified for this application? If not, where did you get yours done?

Thank you!

[yellow1098]

Nice setup! I just got my pretty much the same 340 butler heads delivered for my forged 461....my build is very close to this even the cam specs......the only difference is the cubes and don’t have aluminum block....I am also shooting for 650hp so we’ll see how it goes

[J.C.you]

Originally Posted by Steve C.

"The amount of lash has no effect. It's the velocity at the lash point that hammers the valvetrain. A .030" clearance ramp doesn't have to be any harder on the valvetrain then a .010" ramp. Clearance is clearance."
Mike Jones
Jones Cam Designs

Source : https://www.speed-talk.com/forum/viewtopic.php?t=11597


( Information provided in this post does not represent any endorsement. And unless specified it is not based on personal experience and is offered for general interest only )

.

He would have to provide some proof on that statement....rather than say, "lash is lash". And he didn't allow that all things were the same. Notice he said, " doesn't have to be any harder".... very misleading.

Journeyman thinking with all variables being the same, seat pressure, ramp speed, duration, lift ...
....you have a hammer on a nail.... take it back .016, strike the nail. Then take it back .030 and strike the nail. The difference in the amount of wear on a valve train is almost double.

I don't believe Mr. Jones will get my business.

Another thing overlooked on SR roller lifter and cam wear is the side clearance in the link bars. That will ruin a build for sure.

[punkin]

Well, bummer. I'm being told by my builder that the IAIIa blocks are on back order due to manufacturing shut downs over the COV19 thing. I'll have to divert my attention back at the fuel system and transmission.

[pastry_chef]

Originally Posted by J.C.you

....you have a hammer on a nail.... take it back .016, strike the nail. Then take it back .030 and strike the nail. The difference in the amount of wear on a valve train is almost double.

I guess the word "velocity" is foreign to some. If the hammers velocity remains static the force remains the same also.

Worth reading this Jones line again.. lol

It's the velocity at the lash point that hammers the valvetrain.

I just created two lobes with only a different ramp (lash) height.

.012 lobe lash
Seating velocity
0.00056396

------------------

.024 lobe lash
Seating velocity
0.00056396

[Richie Hoffman]

molnar is out of 4.500 stroke cranks went to order one Friday

[punkin]

Good day everyone,

It's been awhile since I posted an update. Some really long delays due to this COVID19 thing. The block, crank, rods and pistons have arrived.

I ended up going with a Northwind Intake/Butler 340 head combo on the top side and those should be here in a week or so.

The long delay has really been a good thing. I've had a chance to think things through and (again) ask myself what I a really want/need. After talking with my builder once more, and realizing my 90% weekend street use and occasional track time, the cam selection has come down to a hydraulic roller with this profile;

248/254 @ .050, 618/638 lift 112+4 LSA

The engine builder seems to think this will have some really good street manners and still leverage a boat load of torque and should still hit 650 hp.

Any thoughts?

I've decided to retain the 3.55:1 rear gears for now. I may revisit that at a later date. Right now I'm focusing on getting a TH400 built up with a new converter.

[johnta1]

Should be stout!


Using the EFI on it?

[punkin]

I am using EFI. I'm going with the Holley xFlow 900 cfm version.

[pastry_chef]

Originally Posted by punkin

the cam selection has come down to a hydraulic roller with this profile;

248/254 @ .050, 618/638 lift 112+4 LSA

Looks like the same specs used in the 650 HP engine Steve posted (post 10).

[Steve C.]

And note my comments regarding the intake in post #22


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