Here is the article from my last round of testing: http://www.hotrod.com/articles/dyno-tested-vacuum-pump-help-engine-make-power/

Peak power with the vacuum pump and the Wilson ported intake was 775 hp. That is running unleaded premium with out of box Trick Flow 270 heads. I'm sure that more compression would make more power but we're getting close to the limits of a stock block so no reason to turn up the wick anymore.

Great article. I want that Manifold. I’ll trade you my untouched one LOL.

Good info Andy, this makes for an interesting comparison to the Wet sump Flat Tappet Chapman (Engine Masters) 470 that Steve Dulcich did back in 2004, Nearly Identical power!

http://www.hotrod.com/articles/mopp-0405-stage-vi-manifold-casting/

Wonder how the Chapmans would have worked with either the Dry or VP, your Wilson manifold and solid roller? Probably enough to break the block!

Andy: could you supply a part number for this cam? "Comp Cams 264/268 solid roller with HXL and HXX lobes"
Thanks Birdtracker

Yes the power is about the same as Dulcich's Engine Master engine. The big difference is that you can order these heads from Summit and bolt them on. (and they don't cost that much)

It is a custom cam. If you want to duplicate it just ask for 264/268 with HXL and HXX lobes. You'll also need to pick a lobe center.

do you know what the lobe center was on the one dynoed? thanks Birdtracker

Andy how much vacuum did the dry sump pump pull?

Don

True....but how much did the manifold porting cost? or the Dry sump Vaccuum system...or the roller and lifters, or the Pan?

I was just stating power to power, but if someone wants to open the discussion up to "Cherry Picking" the costs. Which dyno ready motor cost more for the 775 HP?

There was nothing wrong with the Chapman heads...other than the Overpriced MP Marketing. Finally Mopar produced n awesome head out of the box...but they blew it with the exorbinate pricing.

The only other "custom" cost vs any other offset intake rocker head (as far as I know) is the $150 billet rocker stands which are arguably well-worth the expense. I think I paid $2400 for my set new but second hand.

I mean I get it, there are "promotional considerations" with every new product testing and we're all happy to have solid tech articles to read, but this is Moparts where we should talk "Apples to Apples"....fairly and objectively.

Ground 108, installed 104

Not a lot, somewhere around 10 to 12 inches. Neither the dry sump or the vacuum pump were set up to pull a ton of vacuum.

The Cam in my 517 is also 264/268 on 108, but it's a Bullet Hydraulic Roller, makes mad torque and pulls to 6800+ It's been in the motor 10 years now, trouble free.

Thinking of Switching to a Solid roller just so I can run the BAM lightweight pressure fed lifters, save on some of that valvetrain mass.

My suggestion to birdtracker is to contact Dwayne Porter (fast68plymouth) for the cam, especially since he may have a different recommendation for lobes, depending upon the application.

I plan on calling Comp this coming week. I would of already but I figured with the holiday I should wait. This is my ideal build for my engine this winter. I have a low deck Indy block that I plan to put Trick flow Max Wedge CNC ported heads on. Would like to run it on pump gas or E-85 and 800-900 hp.
The Comp Cam that I have right now is 2226B 4134B which is a custom grind on 108 center.Lift is 663 on intake and 645 on exhaust with 1.5 rockers. 1.6 rockers would net 703 on intake and 685 on exhaust. Duration is 264 at .050 on intake and 268 on exhaust at .050. Birdtracker

A 2226B/4134B should be 260/266@ .050

There's usually a few thousand extra $$$$$ to get from 800hp to 900hp.

Of course, "low deck Indy block" doesn't really narrow things down too much.
It could be a 451....... Or a 557.

2226 is a HXL lobe that is just a few degrees smaller than the lobe I used. Your 4134 exhaust lobe is a different family. That is an RT lobe with 266 duration.

If you replaced your cam with my cam I doubt you would see much difference. Maybe pick up a little power but I don't think it would be worth the hassle.

800 hp with the Trick Flow 270 heads will take some work. With E85 you can run more compression so you'll want to run as much as possible. If it is a race only deal you'll probably want to throw more cam at it than I'm using. Especially if you have more compression. Don't forget to get the intake ported, that is the key to unlocking some power.

Just an Idea....

So in a post a year or so ago it was mentioned that someone in the Engine Masters comp had used a windowed block to reduce effects of pumping losses by increasing the cubic volume of the sump area (no vac pumps in engine masters?)

So if using a vac pump, its got to pull vs a set volume, if you could reduce that volume, it would work better?

So if you put a big sealed triangular wedge under the valley cover you could take out a bunch of CI from the internal space of the motor and make the pump work better?

Years ago I had a customer bring me his 1968 383 C.I. Charger that he had put a set of after market cast aluminum valve covers on with the stock type PVC and twist on oil filler cap with no vent. It would start and idle fine for a short while(1 1/2 to 2 1/2 minutes) and then slow down by several hundred RPM, the motor was sealed up tight enough that the PCV was making a vacuum in the motor after it suck the pressure out of the motor I put a breather cap on it and he was happy after that
A vacuum pump will do the same thing on a leak free motor
The pumping action of the pistons and rods going up and down and ring blow by will cause crankcase pressure, especially at high RPM

That was my build in 2014 and you are correct-No vac pumps in EMC. I agree with your theory about reducing volume the vac pump has to act on. I also know how theories often pan out. J.Rob

Andy: a few people have shown interest with this topic in reguards to the article. Am I wrong that the 270 heads with your cam and ported intake made 775 hp or did you use a different head? What compression height and ratio were you using with the J.E pistons? Are these a shelf piston? The pump gas is what really interests me cause alot of us still drive ours. Thanks Birdtracker