http://www.thedreyerfamily.com/69f25...50/67dyno1.htm


A bit dissapointing. There is plenty of tuning needed. A/F ratio goes all wrong at higher RPMs. I need to lean out the secondaries for sure and probably the primaries as well.

361 ft-lbs at 3600 RPM and 262 HP at 4200 RPM.

These are non adjusted rear-wheel real numbers.

Assuming a 25% loss through the drive-train that is 481 lb-ft and 349 HP at the crank. 25% may not be enough loss for a C6, dual shaft and Dana 60 combination. Not great, but not bad considering I have done basically no tuning. I just got it running. Considering the peaks are at 3600/4200, it's obviously not breathing right.

That Holley Fuel Injection is looking more appealing.

Feel free to post any advice on tuning these Edelbrock performer carbs.


Greg

 

i guess that is kinda dissapointing, but as you said you are losing quite a bit through the drive train, and i am sure there is lots of tuning yet sense you just got it running, well i dont no much about edelbrocks so i cant help much there, good luck

 

Wow! You are way too rich at higher RPMs. Why didn't the dyno guy tune your carb for you? Ususally they will let you make some jetting changes and point you in the right direction. Fuel injection will run very poorly too if it isn't tuned right. Changing your A/F mixture ratio is cheap. You might be impressed when you get it running right. What was your total timing? How many runs did he give you? Whats up with the squiggley lines at the end of the dyno run?

I need to get mine on a dyno here pretty soon. Who knows how far off mine is. It will be cool as we have about the same duration cams with the exception that yours is a roller. Horsepower comparison should still be good as the extra cubes just bring your peak down in the RPM range and not necessarily in numbers.

 

G, thats really not so bad for a first dyno run. Yeah, you have some tuning issues to work out. Where is the timing set for this run ? Mechanical advance only, or mech. plus vacuum ? How big is the E-brock carb you have ? Would you consider borrowing a Holley and trying that ? My boss and some coworkers tried to tune a big ford (460, cam, big heads, all that crap ) on a edelbrock carb and finally gave up. It was too rich on one side of the carb and too lean on the other, no matter what they tried with jets. After running a borrowed Holley ( 850 that had been tweaked )- 598hp and 600 lbs-ft with no more strange air/fuel gremlins. It was enough to convince me that some of the Edelbrock carbs have some serious issues. Does yours ? DF

 

We didn't do any tuning at the Dyno. That costs money :-) just wanted to get an idea where I was at to do some tuning. I think they gave me a break anyway. 2 runs with AF for $65. It's supposed to be more than that for one run with AF.

At last check, the timing looked pretty good, about 14 initial, mid 30's advanced (nearing the BTC mark on the damper, I consider that 40ish). This is all mechanical on the MSD Dizzy. no vacuum voodoo. I'm thinking about that DUI setup that Proeliator is running. cleans up the engine compartment, and teh vacuum might help with the mileage.

When you consider the RPM level it started giving up and how bad that AF ratio looks, the numbers don't look quite as bad. Have you all seen a decent AF measuring system for the hobbyist? That's what I liked about he Holley fuel injection setup, it has AF measurment and feedback.

I was just happy the truck made it there , made the runs (2) and made it home. Parts of it are still held together with zip ties :-)

So, should I just go much leaner on the secondaries? I've got the Edel tuning kit with a variety of jest/springs and rods.

 

I had several violent backfires through the carb during the first runs. There was some gas burning incidents in the carb. Could I have damaged something resulting in this terrible A/F performance?

 

I just wanted to add that I have never had any luck getting an e-bok to work properly on a real serious engine with a large displacement. I think you'd be shocked at the dyno difference if you put a Mighty Demon on there. I run a Holley HP 950cfm double pumper on the truck in my sig. I mean, c'mon, you practically throw money at your trucks, why skimp on the carb

 

Pro,

What do you think of this Holley Fuel Injection setup?

check it at holley.com , model number 950-24s

The server keeps mutilating the actual link, trying to highlight items for sale here.


Apparently, it can also control some ignition timing parameters.

I really like the idea of real time A/F feedback and tunning via a laptop or PC. plus, I should pick up some gas mileage.

 

I've looked at those before. While I don't have direct experience with them, I've known a couple of guys who did and were pleased. I always thought it would be fun to play around with one myself. However, having talked to many racers about the pro vs cons the general consensus has always been that on a real serious motor you are still better off with a tuned high performance carb. Not that injection isn't a pretty sweet ticket with its own advantages. I guess ultimatly its up to you what your goal is for this motor. For the money, and if it were mine, it stick a Mighty Demon on it, tune it for your engine, and call it a day. 'Course, I don't know how deep your pockets are...if I had extra dough laying around I'd be real tempted to give it a try, especially with the timing correlations. Truth be told, I'm a little biased. I know how to tailor tune carbs, and I know that your engine would really come alive with a real carb (no offense to those of you with eboks). I'm allot less experienced with anything that involves computers and I try to stick with the K.I.S.S principal. So, on a selfish level, I'd say go with the injection route so we can all hear how it works for you. But on a realistic level...my original advice on the carb stands.

 

I'm the opposite, computers and data analyisis don't scare me. tuning a carb by the seat of my pants, scares me.

throw me a carb reccomendation. I noticed summit had some barry Grant demons , with Ford kickdowns, 725 CFM for in the $250 range.

From the Summitracing site

GPT-6402020VF 725 cfm, with Ford kickdown linkage, vacuum secondary, chokeless, Road Demon Jr., 4 barrel carburetor $280.95

on second thought, looking at Bary Grants site, that carb is not a match.

their site ikes this for my application as best I can tell:
1402010V FE

 

Holley 770cfm street avenger works great for me! The Barry Grant demons have had good feedback on them also. I would use a 750 at a minimum and consider an 850 max.

 

Part # 1402010V FE
750 Speed Demon w/Ford kickdown linkage 393 to 477 cid engines &
mild 427 to 455 cid engines

My .050 duration is 222/228


As best I can tell, this is the best match according to the Barry Grant site.

$419 at Summit

 

Thats probably a good choice. Due to the fact that the Demons are wet flowed as compared to the Holleys, a 750cfm Demon is closer to a 825 Holley in flow characteristics. I'd e-mail Barry Grant with your specific engine specs, weight, stall rating, etc., and ask for a recomendation. They actually encourage that and are glad to help you dial in your combo.

 

OK, sent Mr. Grant the details as well as the Dyno graph and A/F plot.

Hopefully thay can help.

Thanks, Pro!

 

Always glad to help a fellow Ford freak Actually, I think its pretty cool that you aren't intimidated by the Holley injection set-up and tuning using computers. I am definitely behind the times...