Another episode of "What will it run?!"

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Eventually I will swap out to 4.10s to complete the combo. I didn't even mess with the Jets this time around. I think I can squeeze a bit more.
 
this is against a ZL1 camaro.. my 12.66 to his 12.88


here's a timeslip of the best run of the day.
31431363_10209216009876169_3963486453148680192_o.jpg
 
Probably run a 12.00 at 110 in Sacramento. Solid run for first time out. Nothing in the slip stands out as being soft. Good from 60' to MPH. Work on the launch, suspension to improve 60' and the rest will improve.

JMO. If you can, drive around the water and back into the wet area with if you have treaded M/T's. They don't tend to need a lot of time in the box. Looks like you did OK there. Lots of folks overheat the MT tires.

Nothing broke, so that's a good day!
 
^^^the only thing that looks "soft" is the almost half second it took him to remember to take off! LOL :poke:
 
^^^the only thing that looks "soft" is the almost half second it took him to remember to take off! LOL :poke:
The off idle launches are wierd. I noticed when I stab the gasthere is a slight delay and I mean slight (left on 3rd yellow)and poof off it goes. Possible the brake pedal still hanging up. Possible I have a carb issue when I do a full throttle stab, Need to figure that out. I also noticed from watching the videos a slight amount of black exhaust, so I'll definitely be messing with the carb for the next time and bring the jet kit with me.
 
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The off idle launches are wierd. I noticed when I stab the gasthere is a slight delay and I mean slight (left on 3rd yellow)and poof off it goes. Possible the brake pedal still hanging up. Possible I have a carb issue when I do a full throttle stab, Need to figure that out. I also noticed from watching the videos a slight amount of black exhaust, so I'll definitely be messing with the carb for the next time and bring the jet kit with me.
I had the same slight delay/hesitation also when flooring it, been messing with carb jetting, pump shot etc and have seen improvements on acceleration especially on the top end, but the slight delay was still there. Turned to timing, was at 18° initial, with 16° mechanical, used a vacuum gauge to increase initial to get the highest vacuum, backed it off slightly. Readjusted the idle screws and idle speed.. Now at 22° initial, reset the FBO plate to 10° mechanical. Better idle vacuum, still pulls strong, and no slight delay any more. Throttle plates were open too much into the transfer slots. Might be worth checking all that to eliminate the possibility?
 
I had the same slight delay/hesitation also when flooring it, been messing with carb jetting, pump shot etc and have seen improvements on acceleration especially on the top end, but the slight delay was still there. Turned to timing, was at 18° initial, with 16° mechanical, used a vacuum gauge to increase initial to get the highest vacuum, backed it off slightly. Readjusted the idle screws and idle speed.. Now at 22° initial, reset the FBO plate to 10° mechanical. Better idle vacuum, still pulls strong, and no slight delay any more. Throttle plates were open too much into the transfer slots. Might be worth checking all that to eliminate the possibility?
I have a full MSD ignition, initial is about 16, with the 18 degree stop (msd billet distributor no vacuum advance). I'll have to play with it some and order the 14 and 10 degree stops from FBO. I will start messing with the mechanical advance spring rates too, honestly I think I still have the light springs in it bringing the advance it early and fast. Lots of stuff to tweak! :thumbsup:
 
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Ok. So I tweaked a few things, jetted the carb for altitude, timing basically went back to where I had it as that seemed to be the sweet spot that it liked.
Best run with 5600ft da was 12.52/106, so basically same run with a slightly worse da. Honestly I think the 750 just isn't enough. The thing launches good and dead hooks, 1.7 60fts but at the top of the run it doesn't nose over it just kinda stops pulling so hard. I also noticed a small oil leak from the front of the intake. So I pulled the intake to fix the gasket and decided to port match since I had it off, it was an easy 3/16 off in some ports, now the head and intake are much much closer. I do believe the next test n tune I'll try an open header/header muffler run and swap to the 850dp.
I really really want to try and get this as close to an 11 as I can at this altitude. Hopefully with the 3.55s, but I think the 3.91/4.10 swap is inevitable.

If you guys have any ideas to get this thing closer to the 11s without power adders, throw them at me.
I have also looked at the DA calculators and they say with these runs at my DA - sea level I would already be 11.60's. But since I haven't taken it down to cali test that, I'm going to take it with a grain of salt.
 
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Ok. So I tweaked a few things, jetted the carb for altitude, timing basically went back to where I had it as that seemed to be the sweet spot that it liked.
Best run with 5600ft da was 12.52/106, so basically same run with a slightly worse da. Honestly I think the 750 just isn't enough. The thing launches good and dead hooks, 1.7 60fts but at the top of the run it doesn't nose over it just kinda stops pulling so hard. I also noticed a small oil leak from the front of the intake. So I pulled the intake to fix the gasket and decided to port match since I had it off, it was an easy 3/16 off in some ports, now the head and intake are much much closer. I do believe the next test n tune I'll try an open header/header muffler run and swap to the 850dp.
I really really want to try and get this as close to an 11 as I can at this altitude. Hopefully with the 3.55s, but I think the 3.91/4.10 swap is inevitable.

If you guys have any ideas to get this thing closer to the 11s without power adders, throw them at me.
I have also looked at the DA calculators and they say with these runs at my DA - sea level I would already be 11.60's. But since I haven't taken it down to cali test that, I'm going to take it with a grain of salt.


To run 11.60's at your elevation you need to find 9-10 MPH and the hook to go with it. That's quite a bit of power to find from a carb. I do agree the 750 is on the small side.
 
To run 11.60's at your elevation you need to find 9-10 MPH and the hook to go with it. That's quite a bit of power to find from a carb. I do agree the 750 is on the small side.
I don't expect to run 11.60s at my elevation but if I can get closer to the 12 flat area that might make me feel a little better. I know 410 gears will help but I don't think it's going to help to get to the 12 flat mark on their own.
This converter seems to be between 3800-4000 stall. Best 60ft is 1.71 with CE 3 way shocks in the rear, stock gabriel replacement shocks in front, 3.55's and ss springs. Wouldn't the 4.10's help the 60ft a smidge assuming traction is still good?
 
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4.30's and that 850DP as you mention should get you much closer to 12.00's and you should be trapping@around 6300 depending on how much slip you got in that verter, just hope that HR cam is up to those rpms...not a fan of hyd. cams, roller or not....

When I ran 3.55's and a 3500 verter, a 750DP, .484 hyd I made 301fwhp and ran 13.3@101...we then went to a .590" solid purple cam, 850DP, 4200verter and 4.30's it ran 12.4@107.8 and made 366fwhp, trapping@6300 in a 3550lbs car. Adding 65hp to the motor is not a 9/10ths gain in ET if you see what I mean. We also put the 750DP with that spec back on as all the racers told me it was too big just to shut them all up.....we lost 2/10ths!!.....
 
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4.30's and that 850DP as you mention should get you much closer to 12.00's and you should be trapping@around 6300 depending on how much slip you got in that verter, just hope that HR cam is up to those rpms...not a fan of hyd. cams, roller or not....

When I ran 3.55's and a 3500 verter, a 750DP, .484 hyd I made 301fwhp and ran 13.3@101...we then went to a .590" solid purple cam, 850DP, 4200verter and 4.30's it ran 12.4@107.8 and made 366fwhp, trapping@6300 in a 3550lbs car. Adding 65hp to the motor is not a 9/10ths gain in ET if you see what I mean. We also put the 750DP with that spec back on as all the racers told me it was too big just to shut them all up.....we lost 2/10ths!!.....
I almost think the 4.30's would be a touch too much for the 27" drag radials. I have noticed that I got my best times shifting at 6200rpm.. I haven't tried any higher, it makes me nervous. lol, but there really isn't much of a difference between 4.10 and 4.30 I would think the difference only a couple hundred rpm.
 
IMO do not throw gears at it until you get, the ignition timing and carb dialed in. WOT jet for max MPH, then accelerator cams and nozzles for best 60'. After tune is right check rpm thru the trap and select correct gear.
 
IMO do not throw gears at it until you get, the ignition timing and carb dialed in. WOT jet for max MPH, then accelerator cams and nozzles for best 60'. After tune is right check rpm thru the trap and select correct gear.
I'm not making any hasty decisions, tweaking and changing as I learn about the car. I want to get it as far as I can with the 3.55's. My build plan was originally for 4.10's, just haven't gotten the extra 489 case I have built yet. I'm actually impressed with the 3.55's, 12.51@5600ft is a pretty stout street car at sea level. Next TnT I will have both the 750 and the 850dp's on hand along with all my little carb goodies for some more tweaking.

I have noticed though, If I load up the converter some, launching from 2000 and up the 60ft suffers.. I get the best ET and 60fts launching off idle and letting the converter flash. I'm not really sure if that is something I can tune out or if that's just how the cookie crumbles.
 
I'm not making any hasty decisions, tweaking and changing as I learn about the car. I want to get it as far as I can with the 3.55's. My build plan was originally for 4.10's, just haven't gotten the extra 489 case I have built yet. I'm actually impressed with the 3.55's, 12.51@5600ft is a pretty stout street car at sea level. Next TnT I will have both the 750 and the 850dp's on hand along with all my little carb goodies for some more tweaking.

I have noticed though, If I load up the converter some, launching from 2000 and up the 60ft suffers.. I get the best ET and 60fts launching off idle and letting the converter flash. I'm not really sure if that is something I can tune out or if that's just how the cookie crumbles.
Every combo is different. Try idle, +200 rpm intervals and see what gets the best 60'.
 
Ok. So I tweaked a few things, jetted the carb for altitude, timing basically went back to where I had it as that seemed to be the sweet spot that it liked.
Best run with 5600ft da was 12.52/106, so basically same run with a slightly worse da. Honestly I think the 750 just isn't enough. The thing launches good and dead hooks, 1.7 60fts but at the top of the run it doesn't nose over it just kinda stops pulling so hard. I also noticed a small oil leak from the front of the intake. So I pulled the intake to fix the gasket and decided to port match since I had it off, it was an easy 3/16 off in some ports, now the head and intake are much much closer. I do believe the next test n tune I'll try an open header/header muffler run and swap to the 850dp.
I really really want to try and get this as close to an 11 as I can at this altitude. Hopefully with the 3.55s, but I think the 3.91/4.10 swap is inevitable.

If you guys have any ideas to get this thing closer to the 11s without power adders, throw them at me.
I have also looked at the DA calculators and they say with these runs at my DA - sea level I would already be 11.60's. But since I haven't taken it down to cali test that, I'm going to take it with a grain of salt.

Bigger carb probably won't help you much at this point (with your RPM). For what it worth, my old 410 was running 10.5's @126mph with a 750 Holley dp with a Proform main body.

As far as gears (with my old 360 combo), when I switched from 3.55's to 4.10's years ago (racing at Bandimere Speedway in Colorado, elevation 5800', DA 9000+ in the summer), I went from 14 flat to 13.5 with the gear change.

Other odds and ends to speed you up (just my results, take with a grain of salt).
  • Remove mechanical fan and switch to electric fan, 2 tenths.
  • Switch to electric water pump drive, 1-2 tenths.
  • Proform main body (versus stock Holley main body with choke horn), 2-3 tenths.
Those 3 would get you the 1/2 second you are looking for....But before any of this I would get the jetting/timing set (keep jetting up for best MPH in the 1/4, when it slows down back it up to the previous best MPH jetting).

Enjoy.
 
I have a 360 combo that started out kinda similar to yours. Search around, recent posts about it..
First thing to do that will make the combo faster is to open up the heads. Thats probably the second thing too....lol
Bigger carb WILL make it faster, but i dont like an 850 on a smallblock, like 950 way better.
Fan and waterpump together( swapping to electric) willl knock a full tenth off, done it lots of times and always the result. 40 years of racing smallblock chrysler, never seen a bigger carb not be faster
In fact, two years ago had a 71Duster with a trick Enginemasters entry 318 magnum motor in it.
Last time i ever had it out we took off all the belts, pushed it to the line fired it and made a pass.11 hundreds quicker than previous pass 45 minutes before on the same day. Btw..... this motor( 318) was a tenth quicker with a 950 on it over a 750. Same 950 its was dyno’ed with at enginemasters competition( google “LA Confidential Mopar “) for the build article.
Smallblocks like a lot of convertor, you could add 1000 more flash to yours, it would make the car quicker, zero doubt about it.
3.91 or 4.10 would be a good gear.

1 port heads
2. More gear
3. Lots more convertor
4. 950 carb
5. Cam upgrade
 
Just to clarify my previous post, I'm not saying a bigger carb is a bad idea, it could help quite a bit....but it is not the magic pill that some folks think.

What I mean by that is, if your current carb is well tuned, on the OP motor there probably won't be a big difference due to the poor flowing heads, small cam, low-ish RPM range....in a nut shell, the demand for air/fuel mix is not as high as it would be for a motor that uses more RPM range, better flowing heads, bla bla bla.

I hope that makes sense. I too am a fan of the 950dp carbs (and I really would like one), and it might help some, or a LOT...but that help could be from the previous carb not being tuned correctly in the first place.

A good example of this comes from my buddies car. He has a well dialed in stroker Valiant, runs 6.60's in the 1/8th. He thought a 950 dp would be better than his smaller (not sure on the size) Demon carb...long story short, he tried for half a race season to get the 950 to out perform his other carb...and it didn't happen, it was not any better, but his wallet was lighter...he ended up selling it within a few months.
 
Just to clarify my previous post, I'm not saying a bigger carb is a bad idea, it could help quite a bit....but it is not the magic pill that some folks think.

What I mean by that is, if your current carb is well tuned, on the OP motor there probably won't be a big difference due to the poor flowing heads, small cam, low-ish RPM range....in a nut shell, the demand for air/fuel mix is not as high as it would be for a motor that uses more RPM range, better flowing heads, bla bla bla.

I hope that makes sense. I too am a fan of the 950dp carbs (and I really would like one), and it might help some, or a LOT...but that help could be from the previous carb not being tuned correctly in the first place.

A good example of this comes from my buddies car. He has a well dialed in stroker Valiant, runs 6.60's in the 1/8th. He thought a 950 dp would be better than his smaller (not sure on the size) Demon carb...long story short, he tried for half a race season to get the 950 to out perform his other carb...and it didn't happen, it was not any better, but his wallet was lighter...he ended up selling it within a few months.


I argued the smaller carb/ bigger carb deal on a thread on Moparts several years ago when i was running a 950 on the stout little 318 i had and wanted to swap to a 750 to see if it night be crisper and 60 foot better. Brett Miller posted and said the car would slow down with the 750.......... it did, and both carbs were dialed in. I thought he was crazy.... he taught me a lesson
His little smallblock runs a 2000+ cfm carb on it. Buddy has a custom 1400 going on his W8 build that should be coming to life in the next few days
I had a 416 like yours a while back, ran about the same, you probably have better heads. I started with 3 carbs Patrick gave me to try from Pro systems( we used to work together years ago)
750/950/1000 all 4150 style, plus an 1100 dominator i had already bought from him. Dominator was easily the fastest, but a 1025 race demon i had laying around ran 99% as good. Suspect part of it was more hood clearance i had with the 4150 stuff over the one dominator.... the 1100. That race demon was a sweet piece, stupid me selling it.
Long story short, if the carbs are tuned, bigger will be faster... have NEVER seen it not be the case
 
Agree totally.....and I'll give you another true race track example.......I persuaded 1 of the "that carb is too big for your 340" racers to try my 850 as it was on his Mk1 Cortina running a Rover V8 3500cc (215ci Buick motor) over his 600 Holley,.. result>2/10ths faster, should've seen the big grin on his face, couldn't believe it. You guys gotta get it into your heads that BIG is better in a WOT race application, I proved it twice at the track back in 1984....I actually ran a 1050 3bbl VS on my car once, had good top end but was rubbish at the hit. And I was only running stock 200cfm 2.02 heads on my motor, a .590 solid, 4.3's/4200stall with that 850DP for a 2/10th gain over the 750 both sorted carbs.....nothing wild.
 
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The 750dp is an AED AED HO-Series Carburetors 750HPHO-RD
Ran it untouched 75/85 jets w/ 16 initial 34 total timing - 12.51@105 5300ft da 1.71 60ft
Changed jets to 71/81 same timing ran 12.52/106 5530ft da 1.70 60 ft (different day)

This time around I'll have the 850 with me to try. I did not build this carb, I bought it last year. Took it apart and found blocked off power valves, dual 50cc accelerator pumps and extended jets in the secondary bowl. Choke horn milled off.
First run will be 84/84 jets and same 16/34 timing - then go from there.
This will be the first test with port matched intake.
heads still untouched.
I was also going to pull the exhaust and see if it helps any, as it may or may not. Only 15min. to yank it so why not.
I'll do all the initial tests with jetting and timing changes launching from idle as it seems to net the best time and 60ft's so far. After that is sorted, I'll start tweaking with the launch rpm and see if I can find a happy spot if there is a better one.

I do believe the heads are a major issue, they will get ported. Probably not till fall or winter. Or I may save up and get a good set ported by a reputable shop/person. We'll see when the time comes.
 
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Its not your heads that are a major issue at this level assuming they are the ones that flow in the region of 253cfm, its your gears, shifting@6200 where you say it likes it is the rpm you should be pulling at the stripe, only way thats happening is with 4.10>4.30's NA, thats where your 12.00's are along with that 850....your not using all the hp that motor has, as you say it goes flat. As I posted earlier adding 65hp to my motor didn't get me the 9/10ths gain in ET, around .4 of that was in the converter/gears upgrade and the better 60 from it, my mph from 101>107.8 shows the 65hp increase.
 
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Its not your heads that are a major issue at this level assuming they are the ones that flow in the region of 253cfm, its your gears, shifting@6200 where you say it likes it is the rpm you should be pulling at the stripe, only way thats happening is with 4.10>4.30's NA, thats where your 12.00's are along with that 850....your not using all the hp that motor has, as you say it goes flat. As I posted earlier adding 65hp to my motor didn't get me the 9/10ths gain in ET, around .4 of that was in the converter/gears upgrade and the better 60 from it, my mph from 101>107.8 shows the 65hp increase.

Nothing wrong with shifting at 6200. My mild 360 runs 11.20’s and i shift it at 6,000
 
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