Anyone have experience with AED carburetors?

[MCfan]

Just wondering if anyone has used an AED carb on their Monte or any other car?  If so, what is your opinion of the HO and/or HPHO series?  AED carbs are hand-built on Holley bodies with custom metering blocks and other significant performance improvements.  More expensive than Holley - Summit sells them.

 

My Swedish racer friend, Jimmy Alund, dropped by today with his 390 hp '66 Chevelle 427 M20 and showed me the AED 750 HPHO carb he installed on it.  He let me drive it and I was amazed how smoothly it performed from idle to WOT and in all gears.  I was getting ready to swap intake manifolds on my modified 402 to get better street manners with a 750 Edlebrock, but I'd rather solve the low rpm streetability problem with a bolt on carb, if possible.

 

Jimmy thinks the same carb that he's running might work well on my modified 402 with a single plane Edlebrock Torker II manifold.  While I totally respect his opinions and advice (nine time European Pro Stock Champion), I am also wondering if anyone here has experience running an AED carb on their Monte?  If so, I'd really appreciate hearing about it.  Thanks.

[Sam (Bones)]

I would NOT use a single plane intake

[monte70car]

I'm with Sam on the not using the single plane. If you are looking for power from idle and up a dual plane is what would be best even on a modified 402 that sees street time. My modified 402 Monte has an old  Edlebrock performer intake for a Q-jet on it, other then that the mod's is a Voodoo cam, full roller rockers and headers car has the low end power and it carries up very well. Now on my 72 has just has a intake, dist and headers, with the intake being a Summit brand dual plane air gap style the dist came in the other day a DUI for a tall deck motor find out this weekend if it will work (waiting on spark plug wires to come in) and the headers are off my 70 which was on it's first BBC from 95.

[MCfan]

I would NOT use a single plane intake

 

I hear you, Sam and Robert - thanks for your input.  I should have been more clear ... my 402 already has the Torker II (single plane) on it (came to me on the car) so I was getting ready to swap it for a dual plane RPM Air Gap.  

 

I think that because the AED carb worked so well on the low profile, single plane manifold on Jimmy's 427 AND after he reviewed all the documentation that came with the car regarding its prior engine modifications (pistons/compression, cam, heads/valves, intake, etc), he felt the special features of the AED carb (4 corner idle, wet flow balanced fuel curve, etc.) might work well without changing my single plane manifold.  The motor was originally built with a 750 double pumper Holley, but the second owner replaced it with a 650 AVS Edelbrock (to get better mileage, he said).

 

I'm going to discuss my situation with the AED technical staff this morning and go from there.  Worst case would probably be trying the 750 AED on my current setup and changing to a dual plane if it doesn't work well.  The AED sounds like a great carb to have either way.  Thanks again.

[dbreese]

Jimmy Alund seems like a cool guy. I liked watching him race PS on the NHRA series. He is a great wheel guy for sure. Do you know if he has a ride for the 2016 season? Big changes for the PS class. Should be real interesting.

 

Sorry Dennis didn't mean to derail your thread. I don't run an AED but I know people who do and they are great carbs.

 

David

[MCfan]

Thanks for your feedback on AED carbs, David.  

 

Yes, Jimmy Alund is a super guy ... smart, down to earth, practical and super friendly in spite of his amazing success in European Pro Stock and some limited involvement and success in NHRA Pro Stock the past few years. Jimmy barely lost the Pro Stock title in Europe this year but he set a new European speed record of 215.09, fourth fastest Pro Stock in the world - Erica Anders, Greg Anderson and Jason Line also broke the 215 top speed mark this year.

 

We discussed the big changes to the NHRA Pro Stock rules and his biggest concern is that being forced to go to fuel injection AND eliminating the former huge hood scoops means the throttle body intake will have to be at the front of the engine instead of on top. That results in less balanced air distribution to the cylinders and a big drop in horsepower.  He says that lots of testing and dyno work has already been done on engines that conform to the new rules and the hp and performance are down significantly from this year (I won't mention any names or numbers here) .  Elapsed times are expected to be higher and top speeds lower for the whole class next year.

 

The shorter wheelie bars will also increase the challenge of keeping the front end down on launch and the 1-2 shift.  He says that rear end gearing will have to be changed and the whole package adds up to huge expense and uncertainty for Pro Stock competitors next year.  I suppose that everyone racing in Pro Stock will have to re-evaluate their desire and ability to compete next year.  Competing in professional drag racing is already insanely expensive so it takes heavy sponsorship commitments to stay in the game.  I know Jimmy loves to compete in NHRA but I'm not able to comment on his plans for next year.

[dbreese]

Totally understand keeping it on the "Down Low" about him competing here in the states. Hope he does.

 

NHRA should have given the PS team more of a heads up on the big changes, like a year or two earlier, instead of right in the middle of the 2015 season. Lots of R&D on engine/chassis = big dollars being spent by the teams even before the 2016 season begins. PS is by far my favorite pro class. 

 

With Tom Compton gone and a new president of NHRA in, I hope they can turn the sanctioning body around. Over the years they (NHRA) have really messed over the sportsman racers. I have a friend that races stock eliminator and because things have gotten so expensive with entry fees and other miscellaneous cost imposed by NHRA he has really had to cut back on the number of events he attends.

 

David

[Sam (Bones)]

what kind of issues are you having, there is no reason why you shouldn't be able to tune that edelbrock carb

[MCfan]

what kind of issues are you having, there is no reason why you shouldn't be able to tune that edelbrock carb

 

Sam, I agree that the Edlebrock carbs can be tuned pretty quickly and easily across a fairly broad range of idle, cruise and power requirements.  I have worked extensively with both a 650 AVS Thunderer and a 750 Performer, building computer spreadsheets of numerous possible rod/jet combinations using the tuning kits offered for each carb plus some individual rod and jet pairs that are not in either kit.  I've tried many settings of the idle circuit, rods/jets/springs for the cruise and power circuits, as well as, the accelerator pump jets and linkage.  I can consistently achieve good to great performance with both carbs from 2500 rpms and up.  Although the 650 seems to plateau or lay over around 5000, the 750 is still going strong when I chicken out.

 

The starting, low speed driveability and shut off run-on issues that affect both carbs from time to time (the 750 being much worse than the 650), are possibly mostly related to the single plane Torker II manifold on the engine.  Before I ever started messing with either carb, I had Jimmy set the valve lash and re-curve the HEI to be all in between 2800 and 3000 (20 degrees total mechanical advance, if I remember correctly).  He blocked the vacuum advance a set the static timing to 16 degrees BTC.  That went a long way to reducing detonation under load but I still have low speed issues. 

 

I guess the proof will be in the pudding because when I drove Jimmy's 427 with a single plane and the 750 AED yesterday, it was incredibly smooth and responsive across the full range of rpms, driving speeds and gears.  I accept that it is likely my fault, but I have never been able to achieve that with either Edelbrock carb with any level of tuning.  Jimmy knows my engine well and he thinks the AED will make a big difference.  The AED technical support rep, Jeff, grilled me on all the details of my engine this morning and also felt I would notice a huge difference, even with the Torker II manifold (of course, he would be bullish if not biased).  I read all of the reviews I could find, mostly on the Summit website, and the AED carbs get rave reviews, with most reporting good to great performance right out of the box with only idle adjustments.

 

So, I ordered an AED 750 HPHO from Summit (or was that Santa?) today, along with their stainless fuel line assembly and AN fitting so I hope to know the answer in a week or so.  Jimmy is going to help me install and tune it along with checking/resetting the timing and valves so I should have a pretty good basis for judging its performance on my motor, single plane manifold and all.  Looking forward to it ...

[Sam (Bones)]

you still didn't tell me your low speed issues, I also feel not using a vacuum advance is costing to some drivability, you may just need a adjustable vacuum advance as I did

 

I also do not know your engine specs

 

shut-off/run-on issues are usually fuel quality/too much timing/ and throttle plates open to far, and with a 10.25 compression ration of the '70 (not sure what you really have or your cam specs) but what I can tell you is that my 454 with 9.6:1 is fine with 93 octane, but try anything less gives me issues every time, so if you have more compression than that and less duration than my cam, you will have higher cylinder pressures which could mean you are on the verge of needing better fuel than pump premium

 

AED are great carbs, so are Pro-Systems, but if you are still having the same issues after putting another carb on it, there are many! other things to consider, what I am getting at is that with 2 different carbs you are still having issues....maybe it's not the carbs

 

what is your idle RPM?

what gas are you using?

[MCfan]

Sam,

 

Here are answers to your questions plus some other specs that might matter:

 

Idle rpm: 790-800 (warmed up & off electric choke)

Gas grade: 93 plus 108 octane booster additive (and lead substitute, of course)

Compression Ratio: 402 block bored +.030", decked .010"; L2337F +.060” TRW 396 forged pistons (47 cc dome, 11.8:1 compression)

No way to know the actual CR, but with those pistons, the block decked and the heads resurfaced, it is higher than I want or need.  Another indicator of high compression is the unusually high and uniform readings I consistently get on my compression gauge for cylinders 1-8 in psi: 240,240,245,230,240,235,240,235 

Oval port Heads: 

3999241

1972

402/454

Open

113cc

240, 300, 330 LS-3 365 LS-5

Heads resurfaced .010"; Valve pockets ground for larger valves: TRW V2562X intake valves (2.190” dia.); TRW S2692 exhaust valves (1.88” dia.) 

Cam: Sig Erson Hi-Flow-IH #120421; single pattern hydraulic, 286* duration (228* @ .050"), 64* overlap, .540" lift @ valve

Intake: Edelbrock Torker II single plane

Exhaust: 1 7/8" full length headers (brand unknown)

Distributor: GM HEI with vacuum advance (not currently connected)

Plugs: AC Delco R44T (have also tried R43TS and R45TS but get more detonation with both)

 

Possibly more than you wanted to know, Sam.  Hope something here is useful.

[Sam (Bones)]

you need to try some 110 octane or higher race fuel not that additive and a R43T plug or colder, you're getting detonation from the extended tip getting too hot from the compression, the 650 carb is no where enough for that build and if it were mine, I'd change the pistons to bring the compression down to a reasonable level 

 

that's a very, very small cam for that compression, I'd say it's turning into a diesel

[MCfan]

Thanks for your assessment, Sam.  You are confirming what I have been feeling and saying for several years ... this motor has way too high of compression (whatever the actual number is) for today's pump gas, even premium.  Changing to R43T plugs is quick and easy but I don't want to change anything before I install the new AED carb to see how that changes the performance.  If I still get detonation (as I expect), I'll change the plugs and pick up some racing fuel at Muscle Car City so I can try that.  I don't think running racing fuel will be an acceptable long term solution.  Changing the cam, heads or, ultimately, the pistons may be necessary next steps.

 

This build originally had a 750 Holley DP but that was replaced with the Edelbrock 650 by the previous owner. Since the Edelbrock 750 Performer is not compatible with the Torker manifold, I am hoping that the 750 AED will be a much better match.  We'll see ...

 

Thanks again for your comments and suggestions.

[Sam (Bones)]

I would try the plugs and fuel before the carb to see if it helps