We just got finished dyno testing a 337 cu in Y-Block for a 1955 Crown Vic. Aluminum heads and High Rise intake were out of box units. Cam is one we designed with Isky for some crate engines we would like to do. 228 degrees @ .050" with .490" lift after lash with 111 degree lobe separation.

We tried 2 carbs, a highly modified 650DP, modified to 700CFM with choke horn removed and down leg booster venturi's. Next we tried one of the new Summit "Autolite" style 600CFM vacuum secondary carbs. Power was identical. The only problem we had with the Summit carb was the fancy chrome fuel line leaked and couldn't be used. Summit supplies a 1/4" thick insulating gasket with open plenum and we used that as a spacer.

We only made 5 pulls since the engine did more than expected on the 1st pull. Timing was set at 33 degrees, no jet changes. Headers are a cobbled up set I made out of some 351 Cleveland headers, 1-5/8 to 1-3/4", runners are 34-40". Rockers are stock 1.54:1. An MSD distributor and new billet steel damper were also used on this engine.

Peak torque was 420 @ 4100, peak HP 392.7 @ 5400. Tests were stopped at 5500 rpm.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

John: I know you have some reservations about engine modeling software, but your dyno tests reflect a bit more midrange torque with almost identical horsepower when that engine is modeled using the Performance Trends Engine Analyser Pro software.

Very close indeed.

The results are outstanding and confirm what I have setting here modeling for the past 8 months.

John, since I'm going to have the heads off, and the radiator out, etc to change the heads and do some other changes, how would that work in my 320 inch motor, with the blue thunder. To refresh your memory, this is a 270 cam, and I think it was one someone had ground on different centers and never picked up, and you suggested it as I was putting the McCullough on then. I'm going with a fuelie unit on this, so if you think it would be an improvement, what's availability?



Mike Richards

So of Seattle

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Great work as alway's John,

You mention Hi rise intake out of the box, Is this what you are considering yours, or is this something new?

Summit Autolite carb? didn't know they were reproducing those, any links to pictures?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Here is a link to the 600 autolite style carb that Summit sells

http://www.summitracing.com/parts/SUM-M08600VS/

Here is a link to some testing done on that summit carb
http://www.fordmuscleforums.com/induction-articles/482814-summit-carb-review-road-test.html
Very nice John on the HP/torque the rate and range is what I am looking for max about 5500 RPM with 400 Hp.

and still 300 HP at about 3600 RPM

It is interesting EAP shows the engine is using about 519 cfm @ 5000 and 539 cfm @ 5500. This looks as if it is pushing up against that carbs capacity. I have no idea why a larger carb might not due a little better. I do know from watching carb swaps on the dyno all carbs are not created the same.

John,

So an almost 400hp (very) streetable y block is possible. It's an interesting build as it's not that different to the mule. Of course there are considerations such as wear, exhaust (this build has headers) displacement and cam. But getting an extra 50hp difference from an already developed engine at a lower RPM with less cam duration is rare. 

I'm guessing that you may get an extra 10-15hp from an extra 15cu/i . Of course the combination of additional component but I'm guessing this is the first of the cams that have been developed for the new alloy heads? Can you tell me please what is the advertised duration of the cam? If others are going to be produced? If these cams will be available without buying a crate engine?  

Good work though.

Cheers

Warren

  

Grizzly (Aussie Mainline)

This was posted on Johns original post  228 degrees @ .050" with .490" lift after lash with 111 degree lobe separation. These are the important numbers, I would guess the "Advertised" duration to be 270 to 280 degrees. Yes you can order one seperately, I ordered one today. They are not in stock. Johns computer is down, it caught a virus. Have to call him.

Don, I agree about 270-280. I'm sort of looking at building an engine in about a years time. So not looking at a purchase yet. When there is a advance in a performance part (like heads) there usually is a jump in complementary parts as the engine is developed in accordance with the change. So I'm guessing other developments and cams as well.

Grizzly (Aussie Mainline)

The cam we used is 262 degrees @ .020" so that is what most companies would call it. I consider it to be closer to 280, since that is the duration at lash.

The high rise intake is just like the picture in our avatar, or icon. Thank you to Ted or Jim for putting a the picture on the home page!

Some improvements have been made to the heads since the first set was sent to Ted for the Mule. Also, this engine has a 3.61 stroke and 6.125 rods making the rod angle 1.69:1.

Block is "0" decked and has 1/16" rings compared to the 312's 5/64-3/32" rings.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico