#41  
Old 04-20-2020, 11:59 AM
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J.C.you J.C.you is offline
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Quote:
Originally Posted by Steve C. View Post
"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.

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Last edited by J.C.you; 04-20-2020 at 12:06 PM.
  #42  
Old 05-09-2020, 04:30 PM
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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.


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  #43  
Old 05-09-2020, 10:35 PM
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Quote:
Originally Posted by J.C.you View Post
....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
Quote:
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


Last edited by pastry_chef; 05-09-2020 at 10:43 PM.
  #44  
Old 05-10-2020, 08:28 AM
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molnar is out of 4.500 stroke cranks went to order one Friday

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  #45  
Old 08-06-2020, 09:09 AM
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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.

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  #46  
Old 08-06-2020, 09:27 AM
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Should be stout!


Using the EFI on it?



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  #47  
Old 08-06-2020, 10:12 AM
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I am using EFI. I'm going with the Holley xFlow 900 cfm version.

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  #48  
Old 08-06-2020, 04:13 PM
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My 517 @ 10.8:1 has a very similar cam/head/intake package and had power peaks of 4300 TQ and 5900 HP. It will pull past 6000 easily. It idles at 800 in gear with a 4000 stall converter. 3.42 gears are plenty so your 3.55’s should work well. With the bigger engine in your lighter car you could probably gear it up some and not loose any performance.

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1.452 10.603 @ 125.09
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  #49  
Old 08-06-2020, 07:25 PM
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Quote:
Originally Posted by punkin View Post
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).


  #50  
Old 08-06-2020, 07:33 PM
Steve C. Steve C. is online now
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And note my comments regarding the intake in post #22


.

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  #51  
Old 08-06-2020, 08:45 PM
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This is all very reassuring. This should be a fun and reliable motor. Thanks for the input everyone.

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  #52  
Old 08-07-2020, 07:57 AM
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Have you used any of the dynamic compression caculators to see where you at with the new cam?

https://www.gofastmath.com/Compressi...tio-Calculator

Thanks

  #53  
Old 08-07-2020, 10:05 AM
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I thank you...no I have not. Thank you for the link. I'll see what I get when I plug the numbers in. The builder is telling me CR should be just a touch over 10.5:1.

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  #54  
Old 08-07-2020, 10:35 AM
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Remember, you will need all the safety equipment to run in the 10s: rollbar, SFI balancer and flexplate, non SFI engine diaper, trans shield/blanket, belts etc unless you only want one lap down the track. What is the bore, stroke, gasket volume, piston volume and head chamber volume? Will it be zero decked?

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1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule.
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  #55  
Old 08-07-2020, 12:07 PM
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I thank you...

A new harmonic balancer and flexplate are in the materials list. The old transmission shield may be too old. I think those things actually have an expiration date on them where SFI is concerned (I'll have to check on that).

As for the other specs, I'll see if I can get those and post them.

Thanks for reminding me of the SFI stuff.

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  #56  
Old 08-07-2020, 07:29 PM
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What cubic inch?

  #57  
Old 08-07-2020, 09:13 PM
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535

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  #58  
Old 08-10-2020, 12:44 AM
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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

  #59  
Old 08-10-2020, 08:50 PM
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If you have the 340/350 heads from SD can you post the flow sheets?

  #60  
Old 08-10-2020, 09:04 PM
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Here is the flow numbers for my SD CNC RP Eddy heads with the heart shaped chamber.
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1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule.
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