EMC 2017 353ci SBC

[randy331]

Would you make any gains with a roller keeping with the same peak RPM?

Yes mostly above peak TQ RPM.
I measured a 236* @.050" Comp Cams magnum hyd roller lobe with a 1.6 rocker on it that gave it the same .600 lift as our EMC lobes did with a 1.85 rocker. It's surprising how much more area it still had at the valve VS our EMC combo.

Randy

[Keith Morganstein]

I was hoping to learn more about this build/effort. A "simple plain jane" combo with exceptional performance is appealing.

I think there is a lot of over-sizing and miss-matched sizing that happens in engine building.
Some will look at a build like this and think, just imagine how much it would make with bigger x or y etc.

If someone posted that combo asking how much will it make, what would the guesses be ?

I'd like to copy it in a larger cube combo, but skip the flat tappet cam.

I have a good 350 block that will clean at .005 over. Be a good candidate for a 3.875 stroke in Honda journal.

Randy

Sometimes less is more, but the matching and refinement is where it's at.

The peak HP and torque might have been somewhat predicted, but I doubt many would have figured over 450 lbs/ft torque from 3500-6600 RPM from a 353 inch SBC.

[Warp Speed]

Was this lift limited by rules or?

Nice piece regardless!

[Keith Morganstein]

Was this lift limited by rules or?

Nice piece regardless!

.600" lift, flat tappet.

[F-BIRD'88]

Would you make any gains with a roller keeping with the same peak RPM?

Yes mostly above peak TQ RPM.
I measured a 236* @.050" Comp Cams magnum hyd roller lobe with a 1.6 rocker on it that gave it the same .600 lift as our EMC lobes did with a 1.85 rocker. It's surprising how much more area it still had at the valve VS our EMC combo.

Randy

This was my initial thought . That if someone wanted to build a street strip motor
based on this they'd be much better off duplicating the net at valve motion and lift area using a street roller cam and appropriate rocker arm.

IMHO to fairly compare a (equally re-worked) dual plane against your good single plane manifold it would need its own optimized camshaft, to be its best. The top end power difference would not be so big in the top end yet retain all the torque. Then it would be fun to split some hairs as to which is actually better overall.
The dual plane will also tend to want a bigger carb..(or 2 x carbs)
EG: the Performer RPM air gap Dual Quad manifold.
The trouble with dual plane manifolds is they are much harder to re-work.

[CGT]

IMHO to fairly compare a (equally re-worked) dual plane against your good single plane manifold it would need its own optimized camshaft, to be its best. The top end power difference would not be so big in the top end yet retain all the torque.

OHHH....Camshaft utopia!

[randy331]

IMHO to fairly compare a (equally re-worked) dual plane against your good single plane manifold it would need its own optimized camshaft, to be its best. The top end power difference would not be so big in the top end yet retain all the torque. Then it would be fun to split some hairs as to which is actually better overall.

There is no cam that would gain back the lost top end power and not loose power at the bottom, much less a legal cam for this years rules.

I'd bet there is no cam that would gain the lost top end even with a loss down low.

Going from the 1.3 breakin rockers to the 1.85s lost power in the first few hundred rpm of the pull, but gained 50 HP peak. How do you go about specing a cam that gets both ?

And you can't just put a bigger carb on it. There were carb restrictions. But we didn't go with the biggest carb we tested. Bigger one didn't gain any power and wasn't good and clean coming into the pull.

Randy

[F-BIRD'88]

I was not refering to a engine that has to fit the EMC rules.

A different engine. A street motor.. When you use 2x 4bbls you don't get the throttle response issues of a single bigger carburetor.
Especially if when in a dual plane. Its a different beast and will want a different camshaft to be its best.

I realize this is not within the rules of the competition.
Nice effort there..

[77cruiser]

Blower time.

[randy331]

Nice job!! D shape ex ports? If so how did they fit up to the headers?

The try Y headers are smaller than the ex ports a little, but the main thing they needed was raised up to match the ports. We had to elongate the header flange .220" to get the roof of the port to match header tube. And I did some hand grinding on the welds inside the tubes.

Randy

[Walter R. Malik]

I was not refering to a engine that has to fit the EMC rules.

A different engine. A street motor.. When you use 2x 4bbls you don't get the throttle response issues of a single bigger carburetor.
Especially if when in a dual plane. Its a different beast and will want a different camshaft to be its best.

I realize this is not within the rules of the competition.
Nice effort there..

You think ...?
Then why don't you just build and test one so you can prove that theory.
Then let us all know that these theories are indeed an actuality.

This is an actual engine ... built and tested, rules or no rules, this is how this engine wanted to be.
Personally, if any combination has not been tested ... it ain't worth speculating.

This is simply shows that utopian mindset that absolutely no engine could possibly be better than anything one can think to do within one's mind.

[randy331]

Blower time.

Fbird shoulda entered the blower class this year.

Randy

[Walter R. Malik]

Blower time.

Fbird shoulda entered the blower class this year.

Randy

No ... he just likes to kibitz.
In my opinion, his world is mainly make believe and hasn't got the where-with-all to enter ANY kind of engine competition; no matter what the class. That would require ACTUALLY performing the things mentioned.

I witness a lot of customers with the same thought process.

[F-BIRD'88]

Personally, if any combination has not been tested ... it ain't worth speculating.


Nice and safe within your little box.

i don't build engine for dyno contests. It has no purpose for me. Just saying.
What you did with the heads is interesting.

[DaveMcLain]

Blower time.

Fbird shoulda entered the blower class this year.

Randy

No ... he just likes to kibitz.
In my opinion, his world is mainly make believe and hasn't got the where-with-all to enter ANY kind of engine competition; no matter what the class. That would require ACTUALLY performing the things mentioned.

I witness a lot of customers with the same thought process.

A contest like the Engine Masters' or building any engine to fit some class is a hell of a lot of work and expense and most people who have not done that don't really understand. This engine looks like an excellent effort to me and is clearly the result of hard work and trying a bunch of stuff to find out what worked best within the framework of the rules.