Andy, Nice engine. You made the comment that a bigger pump would help your internal vacumn. Woundn't a smaller pan also help with that. I have never heard the bigger pan thing when talking dry sump, just add more sections if you need more internal vac and oil control. My 358 with a 5 section barns pulls 17lbs. I know its less cubes but your dry sump should be making some sort of vac. Jon

Andy
thanks for your posts is there any advantages of running a smaller cam with higher ratio rockers
thanks Tom

The 7300 rpm peak reading was a bit of surprise to me to since we usually never run this motor that high. We usually see peak power somewhere around 6800 rpm or so with Max Wedge heads on this shortblock.

The Jones cam measures 180 degrees at .200 and 121 at 0.300. This cam has lobes that are very similiar to the Comp street roller that I ran during the last dyno tests. The street roller lobes were 260 at 50 and 181 at 200 so not much difference there.

The 1.85 rocker ratio adds a bunch of duration at higher lifts when compared to a 1.50 rocker arm so I'm sure that helps the upper end power some. The cam guys I talk to prefer to grind lobes for high ratio rocker arms when they have the chance. They can use a larger base circle and a less agressive lobe shape but still end up with very agressive valve action with high ratio rocker arms.

1.85 is the highest that you can go with the Jesel rocker arms. I'm not sure if someone builds rocker arms with higher ratios than these but this was the limit according to the engineer at Jesel that I worked with. There was plenty of pushrod clearance with the higher ratio rocker arms and we didn't see any problems running the high ratio arms. No sign of valve float even at 7300 rpm so those Comp 26097 springs must have been up to the task.

One of the most influential engine theory books I ever read was called "the design and tuning of competition engines" by Phillip H. Smith

http://www.bentleypublishers.com/product.htm?code=G140

One thing I read almost 30 yerars ago now has been proven to me time and time and time again....the longer the stroke the shorter distance the motor wants the carb from the intake valve....Part of the reason I always felt the Street Dominator worked so well on long arm strokers is the comparatively short straight "line of sight' shot at the valves compared to say the longer taller victor manifold.....now this may not be the reason that the 337 seems to work better in this application but it may be. Runner length for a given port cross-section produces wall friction at high velocities, long runners are very beneficial for torque production....anyone who's ever driven a 5.0 mustang (3" stroke) can attest to that....but once the stroke (and piston speed) is there any runner length beyond "optimum" becomes a resitence. Strokers by and large generate so much low end (based primarily on volume and especially PISTON SPEED) that they really don't need a lot of runner length.

Back in the 80's when the 500" Pro stocks first started covering up their manifolds a big part of that was the trend toward shorter runners and larger plenum areas and was a big departure fro mthe 70's technology tunnel rams. RPM's (again piston speeds) were going up and up and runners got even shorter.

Anyway, I thought I'd throw that in....plus it gives me another chance to ask Andy about the Dyno chart question...'cause we all know peak power don't really tell the story like the torque curves do....especially with wide spaced geared automatics!

PS. Mike Jones is local to me...coincidentally I've been thinking about getting with him on my next roller project

Sorry, dyno curves aren't available.

The camshaft is an R80393/R82401 lobe set from Jones if you're interested. Ground on 110 centers, installed at 106. www.jonescams.com is the website for Mike Jones.

Thanks Andy!

Any chance you might try the Indy single on it...especially since that was what you ran with the flat tappet solid.

There's a lot in your comment comparing the solid to a roller....when you got a big cylinder all thse extra degrees of valve Dwell ABOVE .200 lift really pay dividends in the power department, you trypically/especially see the roller pull away in the RPM range above the torque peak.

first, when comparing the new cam to the one in the old test, even though the comp cam had much more duration, the lift wasnt in the same range to the new stick with 1.85, is this correct? what i'm saying is, there could have been a bunch more power with cam lift where the heads flow best compared to a stick that holds the valve open under the heads peak flow lift

next, is that mopar intake a max wedge port intake like the super victor is?

could the 60 hp increase be due to a big dry sump pan?

Andy, i love reading your tests but you change to many things and you cant really figure out what is doing what. well, except for the fact that the ugly intake is better than the pretty one

If you're comparing back to the MM305 flat tappet cam then the lift isn't that different. The MM305 is a big cam with .650 lift on both intake and exhaust at 1.50 rocker arm ratio. So really this roller cam picked up 60 hp over that flat tappet cam even though the duration at 050 was down a bunch and the lift was basically the same.

I did change the intake manifold from an Indy 440-2 to a Super Victor and I ran the motor as a dry sump, but the oil pan was the same exact pan. Everything else was basically the same.

oh, i missed the comp as a flat tappet. sorry

I never heard of the 337 intake befor now. Is that like the Stage 6 intake? Looks like the valley cover is part of it.

Streetwise, that is an interesting concept and seems to make sense..specially on relatively low RPM strokers. I have been debating, i have a SD and an M1 to try on my 500 ci stroker. Figured I would now use the M1. even considered selling them and getting a Victor. After reading this, think that might be a waste of money when i already have the best intake(s) for the job.

I just don't consider the curves to be all that reliable so I don't bother to post them. The peak numbers are repeatable so I'm comfortable with them.

One thing I have noticed with this engine is that the Indy claim of 100 hp is fairly valid. I've gone back and forth several times on this shortblock between CNC ported Edelbrock (or MP) heads and the Indy EZ heads. The EZ heads always make about 100 hp more than the std port window heads. It isn't a perfect apples to apples test since the compression drops a point when you switch to the Eddy heads and the rocker arm ratio drops from 1.70 to 1.60, but it is close enough to draw some conclusions.

That makes this thread all that much better!

The shortblock consists of a 1977 440 block, 440Source crankshaft, SCAT rods, Diamond pistons. The block is all stock with the exception of the ARP main studs. No girdle, no block filler, no aftermarket main caps, etc.

The 440Source crankshaft was installed right out of the box as were the rods and pistons. Main and rod bearings went in without any issues. I didn't have to scrape bearings or re-machine the crank or anything like that.

This motor has been on and off the dyno now for a couple of years without any issues. It has somewhere between 50 and 100 dyno pulls on it now but I don't actually keep count.

We changed rocker arm ratios during the dyno test session. The more I work with the Jesel setup the more I like it. Just crank each cylinder over to TDC and pull the shaft. Sure is a lot nicer than having to yank the entire shaft assembly off and re-work it.