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Discussion Starter #1
Chris,

What do you like to see for clearance between the lifter body and camshaft lobes ?

The block is a Dart Iron Eagle 9.315" deck height with the cam raised an additional .050" with a 55mm camshaft from LSM for symmetrical port SBC heads, BD2000. The lifters are Crower Severe Duty .903 diameter.

All machine work on block was performed by LSM Engineering. The timing belt is a Jesel with the new CV products low drag ball bearing thrust assembly to hold camshaft endplay to .001" or less.

We currently have .023" in the forward direction and .029" in the rearward direction, so the cam is positioned very close to center in- between the lobes.

Please advise your thoughts or experience.

Thanks,

Chris Cobb
 

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That'll do. That's actually pretty good clearance(as long as your endplay is under control). I just built an engine with the .904 lifters and the same block work from LSM... so I know what you're concerned about. Recently did a Ford engine with .904 lifters and I can't recall off hand but I think I was down to about .015" clearance on one side... no issues yet :-D

Did you have LSM move the intake lifters at all to help with pushrod angularity?

If you don't mind, keep me posted on your results with those heads. I'm VERY curious to see how they work out for you. Who did the port work?

Also, how is the quality of that CV thrust setup? I haven't had the opportunity to see it yet.

Chris
 

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Discussion Starter #3
Chris,

Thanks for your input on this matter. The camshaft endplay is virtually eliminated with the CV Products Thrust assembly. It's a very trick piece and the quality is great.

The lifter bores were moved, but the intake pushrod is still not straight.

What size pushrods do you like to use with LSM700B springs ?

Any difference on size for the intake and exhaust with the wide lobe seperation camshafts ?

As for the heads, they were ported by Kevin Self(Self Racing Heads & Engines) in Durant, OK. He's was very highly recommend by Brodix. He's the guy that developed the SE100 two piece manifold for standard 23 deg head stuff.

A little more information about the engine.

414 cid
Bore: 4.165"
Stroke: 3.800"
Rod Length: 6.100"
Compression Ratio: 15.1 to 1
Camshaft: LSM Grind for NOS (283/300 @ .050 - .925"/ .882" Lift 114 LSA - 55mm)
Rocker Arms: T&D shafts 1.85 intake ratio / 1.80 exhaust ratio
Heads: Brodix BD2000 by Kevin Self
Intake: Custom Sheet Metal by Kevin Self
Induction: 4 - 2bbl throttle bodies by Applied Nitrous Technology for EFI
EFI System: FAST by Applied Nitrous Technology
NOS System: 2 Stages by Applied Nitrous Technology
Headers: Custom Step Headers by Don Kromer @ Kromerkraft with merge collectors

Once again, thanks for the input on the lifter clearance.

Chris Cobb
 

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Chris,

Stick as big dia. pushrod that you can fit in it. If you can fit 9/16 dia. put it in there. Somewhere around .150 wall.

LSM makes some decent pushrods, but I'd only use them for short pushrod app's.... Yours will probably be fairly long with the raised deck, and tall heads....

Sounds like a killer engine combo. Those are the best valve springs I've ever used....

I haven't seen the intake ports on those heads. You don't know how long the runners are do you? What about port height? What is the height at the entry?

What are you doing with this engine?
 

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Discussion Starter #5
Chris,

The biggest pushrod I can fit on the intake is a 7/16" tapered to 3/8" to clear the intake runner and the water fitting that goes thru the intake flange on these heads. I was planning on putting a 1/2" straight wall pushrod on the exhaust with a .187" wall.

Some of the information on the heads that you inquired about in your response.

Port Length: 5.30"
Port Volume: 315 cc
Port Shape: Oval

I can get you the dimensions on the port later today.

The eninge is for a local Limited Street heads-up class. It's a 91 camaro with ladder bars and true 29.5 x 10.5 tires. We went 5.40-5.50 with a 23 deg Brodix 10XRISP headed 408 with a single stage fogger (275hp) tune up with 1.25 - 1.27 sixty foot.

This is a completely new engine combination that I've been working on for about 18 months. The goal is to build as much power as I can and then add NOS.

Chris Cobb
 

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Discussion Starter #8
Chris,

More head information on the BD2000 heads.

Distance from deck to bottom of port: 1.835"
Port Size @ intake flange: 2.25" x 1.45" w/.75" radii corners (oval shaped)
Min. Cross Sectional Area: 2.8218 sq. in.

Intake Valve Size: 2.200" with 55 Deg Seat
Exhaust Valve Size: 1.600" with 56 Deg Seat

Spark plug location has been moved in towards the center of the combustion chamber. The combustion chamber size is 40.5 cc.

They now have a cast manifold for these heads, but I have yet to see one in person.

We should have the engine on the dyno in the next 4-5 weeks and then out on the track by late August early September.

If you have any further questions on the heads just let me know.

Thanks,

Chris Cpnn
 

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Thanks for the info!! That's nice looking intake runner geometry... It's pretty short for the height and that's good.... I was checking out the cast manifold today and that thing looks like a big piece of junk.... you're way better off with the sheetmetal piece. The average runner length would end up being a monstrosity..... Good move on the plug position too!!! :wink:
 
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