2009 EngineMasters, What's new?

Post by **CamKing** » Sun Sep 27, 2009 11:40 am

rmcomprandy wrote:Oddly enough, the tunnel-ram made more torque average while the upper range horsepower average remained about the same as a single plane and single 4 barrel.

How big is the engine?
I could see this happening with a big cube engine, but I wouldn't think that to be normal for an engine under 400ci.
Does the tunnel ram have real long runners?

dan miller · Post by **dan miller** » Sun Sep 27, 2009 1:55 pm

Hello Mike

Early hemi 365 cid, 355 cfm intake flow, 4.012" X 3.608".

Danny

MadBill · Post by **MadBill** » Sun Sep 27, 2009 7:57 pm

Hmm... Vizard's formula would suggest a choke of ~46 mm and a throttle bore of 58 mm for this app. Not a cheap or easy to find size..

His flow tests show for example that going from a 34 to 36 mm choke on a 40 mm carb increased the flow by only a couple of percent but reduced the signal at the aux. venturi by 50%...

Larry Widmer · Post by **Larry Widmer** » Sun Sep 27, 2009 9:15 pm

48's weren't adequate for some of the old-school engines running lass than 350cid. I used 58mm Webers on the 494 CanAm engine I ran in my street Boss, but I had to use a "pancake" plenum that was 1.25" deep to allow the engine to breathe,
In the mid-eighties, we converted two of the mini-Indy engines to carbureted configuration for an SCCA race. The rules only allowed Webers with extremely small throttle bores. Once again, a shallow plenum connecting all of them saved the day.
If you have the time to machine one (a plenum), you may find it'll work for you too.

revolutionary · Post by **revolutionary** » Sun Sep 27, 2009 10:06 pm

Guess we'll find out in the morning how our stuff fares. Thanks to Mike Jones for help with some cam options. I think they will do well. I felt better about last year's entry than this year but who the heck knows how these things go. It might not make any power but it looks shiny.

dan miller · Post by **dan miller** » Sun Sep 27, 2009 11:10 pm

Hello Daryl

That certainly is shiny. It's so pretty that they ought to give you an extra 50 points.

Like the looks of the intake. Sure wish someone made something like that for an early hemi.

How many cubes?

See you in a week.

Danny

dan miller · Post by **dan miller** » Sun Sep 27, 2009 11:19 pm

Hello Larry

I considered doing just that, but ran out of time.

Considering the dismal (thus far) air fuel curve, it might have been worthwhile to budget some time for experimenting with a plenum.

We have 1" carburetor spacers, and I was thinking of inserting thin wall tubing (maybe around .900") into them and running short hoses to a plenum. Or, possibly connecting cylinders in such a manner that an active cylinder could utilize the carburetor airflow of an inactive cylinder.

I've had the cure. From now on, I'm a fuel injection person. lol

Thanks again, Danny

Parkhurst · Post by **Parkhurst** » Mon Sep 28, 2009 1:13 pm

We're up and running. 300+ pulls on the 'test' goodies, and the jewelry got installed over the weekend. Now it's back to the pump and we'll see what we find with the changes. Would love a little more bottom end, but I've got to say- the top end is pretty damn good.

Maybe everything in life just gets better at 7,000 rpm...

We'll be there, ready to play. We've been tuning on local MN gas (lots of alky in it) but we've got some of the spec gas here for the final tuneup before we roll out. With less alky, it should be measurably better. We'll see.

~SP~

Post by **nitro2** » Mon Sep 28, 2009 5:02 pm

Parkhurst wrote:We're up and running. 300+ pulls on the 'test' goodies, and the jewelry got installed over the weekend. Now it's back to the pump and we'll see what we find with the changes. Would love a little more bottom end, but I've got to say- the top end is pretty damn good.

Maybe everything in life just gets better at 7,000 rpm...

We'll be there, ready to play. We've been tuning on local MN gas (lots of alky in it) but we've got some of the spec gas here for the final tuneup before we roll out. With less alky, it should be measurably better. We'll see.

~SP~

300 + pulls

Will any of the details make it into your website/ magazine?

1989TransAm · Post by **1989TransAm** » Mon Sep 28, 2009 5:28 pm

I have to agree with Nitro2. With over 300 pulls there should be a gold mine of information.

I'm also interested in what Danny has to say with all his dyno pulls.

dan miller · Post by **dan miller** » Mon Sep 28, 2009 10:16 pm

We’re headed back to the pump one more time tomorrow. I’m starting to get a better idea of the function of Weber Carburetors, and hopefully we can make some sense of the lean spike.

I’ve been a little concerned that our merge choke point was a little tight @ 2.375" ID, so I opened it up to 2.750" ID. It’s a roll of the dice - hero or zero, as there’s no going back to the small choke.

I’ve spoken with everyone that I could find in the “World of Weber”, and have come away without much insight. In fact, almost every source is in total disagreement with every other source. Either the whole Weber deal is super top secret, or some of the folks don’t know as much as I’d expect for someone who makes their living in/around Weber carburetors.

Harry Brannan, who posts on this site, is very knowledgeable and articulate. He has taken the time to ‘splain things to us, and offered what I consider some very sage advice. Thank you very much, Harry.

Good, bad, ugly (or very ugly), I’ll post our results tomorrow night.

Danny

1989TransAm · Post by **1989TransAm** » Mon Sep 28, 2009 11:22 pm

Good luck tomorrow and looking forward to your findings.

revolutionary · Post by **revolutionary** » Mon Sep 28, 2009 11:38 pm

In honor of Joe Caroll we boke on the dyno tonight as well. Had our hail mary cam in and it killed a pushrod in less than a minute. Swapped cams, reajusted stand height for less lift and borrowed a rocker cup and got it going again with a less angry cam. Just made one little pull before closing up for the night and it looks ok but we are miles away. Lets hope the DTS picks up a hundred points or so...

Parkhurst · Post by **Parkhurst** » Tue Sep 29, 2009 7:40 pm

nitro2 wrote:300 + pulls Will any of the details make it into your website/ magazine?

I don't work for any magazines anymore.

I'm working with TPIS on this engine, and it'll all show up on their website. We're all learning. Luckily we haven't hurt anything yet.

Post by **CamKing** » Tue Sep 29, 2009 8:31 pm

revolutionary wrote:In honor of Joe Caroll we boke on the dyno tonight as well. Had our hail mary cam in and it killed a pushrod in less than a minute. Swapped cams, reajusted stand height for less lift and borrowed a rocker cup and got it going again with a less angry cam. Just made one little pull before closing up for the night and it looks ok but we are miles away. Lets hope the DTS picks up a hundred points or so...

I assume you had the other brand cam in?