RAMM
Well-Known Member
The straight booster sucks but if he has a downleg then that is a different story. J.Rob
Upgrading my 340
- Thread starter Raul
- Start date
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The straight booster sucks but if he has a downleg then that is a different story. J.Rob
RAMM
Well-Known Member
Oh Jesus here we go with another more than likely over-cammed, under compressed, no-quench, slapped together combo. Only lurking from here on out-unless OP posts build sheet with actual info. J.Rob
SLOPAR72
Well-Known Member
****... You are funny..... I could totally see you building my next motor just for the sarcasm value....
JW
Raul
Well-Known Member
The engine is attached to a Tremic 5-speed.
I've got an 8 3/4 rear end with 3.55 gears in it. Only thing done to the chassis besides this rear end swap is: Beefed up rear springs, installed gas shocks, added traction bars, a front sway bar and upgraded front power discs
.
I really appreciates the input from you all. Wish l had kept up with this fish and motor, in all the years I've had it.
Mind 'ya, The purpose of my car is mostly sentimental everyday driving tho I'd like to get on it from time to time and take it to the track in spring/ summer. I'll dig up my build sheet over the weekend and share more of the internal build.
My initial thoughts was changing the four bbl to the 6pak for power gain but also for the big fashion statement. Tho it is a great expense, if the power output increase can be obtained with a 750cfm and 1 3/4 headers, opening the passages of the fuel/exhaust flow, then that surely would cost less than the anticipated $2800.00 6pak setup with a much better gain.
Rumblefish: Are the tti headers you've mentioned with 1 3/4 pipes full length headers or shortys? Does it allow for easy access of removal of spark plugs? My full length headers hang to low and are easily scraped. I am definitely game on changing my headers out. If the tti brand is full length, do they tuck in nicely under the car? Or do short tube headers perform just as well. And what about the intake manifold? I bought an old summit racing dual plane intake.Are there better dual plane intakes around? I once had an Eldelbrock LD340, I noticed a good gain with that one over the stock intake back in the day when I had the stock carter afb carb on it. So far, I am hearing a 750cfm double pumper and 1 3/4" tti header pipes.
I've got an 8 3/4 rear end with 3.55 gears in it. Only thing done to the chassis besides this rear end swap is: Beefed up rear springs, installed gas shocks, added traction bars, a front sway bar and upgraded front power discs
.
I really appreciates the input from you all. Wish l had kept up with this fish and motor, in all the years I've had it.
Mind 'ya, The purpose of my car is mostly sentimental everyday driving tho I'd like to get on it from time to time and take it to the track in spring/ summer. I'll dig up my build sheet over the weekend and share more of the internal build.
My initial thoughts was changing the four bbl to the 6pak for power gain but also for the big fashion statement. Tho it is a great expense, if the power output increase can be obtained with a 750cfm and 1 3/4 headers, opening the passages of the fuel/exhaust flow, then that surely would cost less than the anticipated $2800.00 6pak setup with a much better gain.
Rumblefish: Are the tti headers you've mentioned with 1 3/4 pipes full length headers or shortys? Does it allow for easy access of removal of spark plugs? My full length headers hang to low and are easily scraped. I am definitely game on changing my headers out. If the tti brand is full length, do they tuck in nicely under the car? Or do short tube headers perform just as well. And what about the intake manifold? I bought an old summit racing dual plane intake.Are there better dual plane intakes around? I once had an Eldelbrock LD340, I noticed a good gain with that one over the stock intake back in the day when I had the stock carter afb carb on it. So far, I am hearing a 750cfm double pumper and 1 3/4" tti header pipes.
RAMM
Well-Known Member
I'm takin the bait 'cuz I have a little more coffee in my mug.
Go with the 6pak and you will LOSE power and money.
TTI's are great go with a 1 5/8" primary and 3" pipes from there on out.
A 750 is too much, grab a Holley 650 Ultra XP and enjoy.
An Edelbrock RPM Air-Gap or Non Air-gap is really tough to beat although an old Weiand X-celerator is a kick *** single plane.
Take the time to really understand your timing--intital, curve, total, vacuum. Almost everyone drops the ball here.
Love the 5spd and rear gear--headed down that road myself. J.Rob
Raul
Well-Known Member
"Take the time to really understand your timing--intital, curve, total, vacuum. Almost everyone drops the ball here."
I know nothing about this. Love to learn more, can you enlighten me as to what to look for and how to even change results? Or point me to a good book to educate myself with this....I believe the air gap was mentioned in a couple previous posts, I will surely look into that. Do different brand carburetors really outperform one another? I've got a 650 double pumper, would there be that much of a difference? My carb is jetted to my engine....is the boost in power substantiated in getting the car returned to the holley?? But the intake is worth looking into and definitely the header pipes as well.
I know nothing about this. Love to learn more, can you enlighten me as to what to look for and how to even change results? Or point me to a good book to educate myself with this....I believe the air gap was mentioned in a couple previous posts, I will surely look into that. Do different brand carburetors really outperform one another? I've got a 650 double pumper, would there be that much of a difference? My carb is jetted to my engine....is the boost in power substantiated in getting the car returned to the holley?? But the intake is worth looking into and definitely the header pipes as well.
nm9stheham
Well-Known Member
OP, in reading your uses for the car, keep in mind that doing lower track ET's can work against good driveability; it doesn't have to be that way but a lot has to do with your present parts inside the engine. A lot of 'driveability' is subjective, so let's keep that in mind.
Can you help us with:
- The pistons inside your engine? A part number and brand will do.
- The cam in your engine? If you don't know specs, then part number and brand will do.
- Is this a stroker, or did it use the stock type crankshaft?
For me, where good street driveability is a top goal, the 6 pack is not the way to go. I don't perceive that you do a lot of tuning, and while a 6 pack can be done, it is not a simple task. The whole original need behind it is actually outdated IMHO; newer single carbs can do the same and are a lot simpler to work with. So the main value to anyone is that it IS a six-pack, and if that does a lot for you, it can be worth it. But it will cost you in street operation.
Good headers will help you ALL across the RPM range so that is of great value. The right tube size and is important. If a long collector is not available, then consider adding one, as that helps low end torque; that all helps in driveability.
Different carb brands can have different general characteristics; a "spreadbore" type will have smaller primaries and will tend to be easier to tune for low speed use, but a lot of carb selection seems to be what a person is comfortable with. There is enough tuning info out there to make them work.
BTW, if you have 320 HP at the wheels in a chassis dyno, then maybe you have 360 HP at the crank as a guess. As a very rough estimate, you have 10% more peak power to possibly gain assuming the AL heads you now have are Edelbrock Performers. Is that what they are?
Can you help us with:
- The pistons inside your engine? A part number and brand will do.
- The cam in your engine? If you don't know specs, then part number and brand will do.
- Is this a stroker, or did it use the stock type crankshaft?
For me, where good street driveability is a top goal, the 6 pack is not the way to go. I don't perceive that you do a lot of tuning, and while a 6 pack can be done, it is not a simple task. The whole original need behind it is actually outdated IMHO; newer single carbs can do the same and are a lot simpler to work with. So the main value to anyone is that it IS a six-pack, and if that does a lot for you, it can be worth it. But it will cost you in street operation.
Good headers will help you ALL across the RPM range so that is of great value. The right tube size and is important. If a long collector is not available, then consider adding one, as that helps low end torque; that all helps in driveability.
Different carb brands can have different general characteristics; a "spreadbore" type will have smaller primaries and will tend to be easier to tune for low speed use, but a lot of carb selection seems to be what a person is comfortable with. There is enough tuning info out there to make them work.
BTW, if you have 320 HP at the wheels in a chassis dyno, then maybe you have 360 HP at the crank as a guess. As a very rough estimate, you have 10% more peak power to possibly gain assuming the AL heads you now have are Edelbrock Performers. Is that what they are?
Raul
Well-Known Member
ok now that im up to speed.
yellow rose said: ↑
Don't waste your time with a 6 pack.
The real question is what's wrong with what you already have. I doubt I would have used a 650 just because the booster swallows bilge water but that can be addressed.
could you educate me on that?
Now whether you go with efi or a bigger carb, you combo need to be dialed in first! as has been ask do you know you initial timing, how about total timing? this would be the first you need to know. Do you have a timing light to check?
OK let me Back Up a little bit here. You have the eng in the car? if so, what is the least exciting part about driving it?
What part of driving it, do you want the motor to do better?!
answering that, will help us all, help you..............
yellow rose said: ↑
Don't waste your time with a 6 pack.
The real question is what's wrong with what you already have. I doubt I would have used a 650 just because the booster swallows bilge water but that can be addressed.
could you educate me on that?
Now whether you go with efi or a bigger carb, you combo need to be dialed in first! as has been ask do you know you initial timing, how about total timing? this would be the first you need to know. Do you have a timing light to check?
OK let me Back Up a little bit here. You have the eng in the car? if so, what is the least exciting part about driving it?
What part of driving it, do you want the motor to do better?!
answering that, will help us all, help you..............
on now on to the carbs
I have a 408 that was built for torque. at 5800 rpm is out of breath. These carb calculators say that a 650 cfm carb was all that i needed. seemed like everybody said that i needed a bigger carb. there was mention of how much vacuum aka restriction there was at top rpm. I hooked a vacuum gauge to a under carb port and to my gauge.
wide open throttle, 3 gear 5800 rpm. i had like 1 inch of vacuum(no restrictiction don't need bigger carb.)
I ran that 650 dp for a year and a half. My only other choice i had on hand was a 850 demon carb(basicly a holley carb)
One day i bought a kit, rebuilt my 850 and jetted it for my attitude. The carb ran better all the way thru the power range, with a better et to boot. I real thought the 850 would drown it or bog causing me to do some squirter changes to make it work. didn't have to change anything but my jet side. It even 60 foots better than the 650
Disadvantage of the 850????? the 650 is a better street carb as it sips fuel better
my car travels on a car trailer everywhere it goes.....850 stays on.
Man i can't wait for the snow to get the he ll out of here.
I have a 408 that was built for torque. at 5800 rpm is out of breath. These carb calculators say that a 650 cfm carb was all that i needed. seemed like everybody said that i needed a bigger carb. there was mention of how much vacuum aka restriction there was at top rpm. I hooked a vacuum gauge to a under carb port and to my gauge.
wide open throttle, 3 gear 5800 rpm. i had like 1 inch of vacuum(no restrictiction don't need bigger carb.)
I ran that 650 dp for a year and a half. My only other choice i had on hand was a 850 demon carb(basicly a holley carb)
One day i bought a kit, rebuilt my 850 and jetted it for my attitude. The carb ran better all the way thru the power range, with a better et to boot. I real thought the 850 would drown it or bog causing me to do some squirter changes to make it work. didn't have to change anything but my jet side. It even 60 foots better than the 650
Disadvantage of the 850????? the 650 is a better street carb as it sips fuel better
my car travels on a car trailer everywhere it goes.....850 stays on.
Man i can't wait for the snow to get the he ll out of here.
Raul
Well-Known Member
This certainly helps as well. I don't think they're the Edelbrock brand but they lo ilk similar to thrm
What does it mean, to swallow bilge water??? And what booster are you referring to? The car is down right now in body/paint restoration I can't check the timing at this time.
I found my build sheets;
I've got Pro Comp Heads Made by Speedmaster. Don't know the specs other than 2.02 intakes and 1.90 exhaust
The carb is by quick fuel techno Street performance carb
The Cam is a custom ground cam. Intake lift .525 with 279 duration exhaust lift is .530 with 287 duration. Lobe center is 109 Intake c/l is 103. On a second page it states intake gross lift at cam. 350 with duration 227 exhaust gross lift at cam is .353 with 235 duration
I would like to see a stronger acceleration. It's got power as it builds rpm but the acceleration and power to get up and go at the drop of the dime almost always requires 2nd gear. Off the line I know it could do better. I'd like to chirp the tires with ease as I shift from 1st to 2nd or even be able to break traction without popping the clutch.
What does it mean, to swallow bilge water??? And what booster are you referring to? The car is down right now in body/paint restoration I can't check the timing at this time.
I found my build sheets;
I've got Pro Comp Heads Made by Speedmaster. Don't know the specs other than 2.02 intakes and 1.90 exhaust
The carb is by quick fuel techno Street performance carb
The Cam is a custom ground cam. Intake lift .525 with 279 duration exhaust lift is .530 with 287 duration. Lobe center is 109 Intake c/l is 103. On a second page it states intake gross lift at cam. 350 with duration 227 exhaust gross lift at cam is .353 with 235 duration
SLOPAR72
Well-Known Member
3 pedals....... Put an automatic in it and you will go faster..... Unless you have an expensive clutch to get it away from the Starting line.... Something else is Chassis Dyno results can be skewed due to no Converter Slippage meaning you may see a bigger number than what you will with an automatic. A close friend of mine who has now passed ran a dyno at a well known carburetor entity and that was his findings running cars.......
However 3 pedals is a blast. What is the Low Gear ratio of the Transmission? 60ft,330, and 660 et and mph if you have that info.....
JW
However 3 pedals is a blast. What is the Low Gear ratio of the Transmission? 60ft,330, and 660 et and mph if you have that info.....
JW
Raul
Well-Known Member
I don't have that info with me, but I can possibly look it up later. I'm on my Way out to help with the body/paint restoration right now. But I'll check up on my thread conversation later today
Raul
Well-Known Member
I really haven't taken note of that but I'd imagine around 1800 though this is an off the wall guess
I'd bet the headers are hooker 1 5/8" style.
320RWHP should be a bunch better than 100 mph.
320RWHP should be a bunch better than 100 mph.
Almost every dyno shootout involving a 6 pak goes like this; run the 4bbl, jet the 4bbl, toss the 6pak on run it as is & call it a day, & the 6 pak usually actually puts out
more at certain points in the curve, but has the "kick-in" sag somewhere in said curve.....max output is almost always near = or better. Yes it is more difficult to tune, &
ultimately it's worth is in the coolness dept., but they run perfectly fine dialed in. Costs lots more $$$$$ to do right.......................
Raul
Well-Known Member
They're not hookers, I was really low on funds at the time and I thought any header is better than stock exhaust manifolds. These cost me around $200 new and we're a pain to install. 11/2" pipes. They've got to go soon and be replaced with 1 3/4 tti's
I've gotta run to help restore the bodywork/laint. Thanks to all who are trying to help me produce more without opening up the engine back up. I'll be back soon!
Your at a crossroads performance wise.
Transforming an A Body into a 13 second car is pretty easy and make for a fun and very daily driver kind of car. But after this every performance gain cost more per hp and cost in the drivablity department.
It seems like your looking for something to buy that will gain you a huge improvement in power beside nos everything is 5-10 hp improvements carb, headers, intake etc...
The only thing that's left to give huge power that doesn't require a complete redesign of your engine would be fully ported heads.
But before I'd buy anything. I'd start a new thread in the racing forum and dial in what you have before trying to move to the next step.
P.S. What tires do you run at the track ??
Transforming an A Body into a 13 second car is pretty easy and make for a fun and very daily driver kind of car. But after this every performance gain cost more per hp and cost in the drivablity department.
It seems like your looking for something to buy that will gain you a huge improvement in power beside nos everything is 5-10 hp improvements carb, headers, intake etc...
The only thing that's left to give huge power that doesn't require a complete redesign of your engine would be fully ported heads.
But before I'd buy anything. I'd start a new thread in the racing forum and dial in what you have before trying to move to the next step.
P.S. What tires do you run at the track ??
nm9stheham
Well-Known Member
Good info; all that helps. Find out the pistons that you have so we can get a complete idea of the guts in the engine. If it was a top end change out on a stock engine, or if the bottom end was rebuilt to stock specs, then just let us know that.
I am suspecting that with the heads, assuming they are the Small Block Edelbrock clones, then the pistons in your engine are not stock replacements. And I assume you mean 1.60" on the exhaust valve, not 1.9"....
Head gasket brand and part number would be good to know too.
I am suspecting that with the heads, assuming they are the Small Block Edelbrock clones, then the pistons in your engine are not stock replacements. And I assume you mean 1.60" on the exhaust valve, not 1.9"....
Head gasket brand and part number would be good to know too.
RAMM
Well-Known Member
on now on to the carbs
I have a 408 that was built for torque. at 5800 rpm is out of breath. These carb calculators say that a 650 cfm carb was all that i needed. seemed like everybody said that i needed a bigger carb. there was mention of how much vacuum aka restriction there was at top rpm. I hooked a vacuum gauge to a under carb port and to my gauge.
wide open throttle, 3 gear 5800 rpm. i had like 1 inch of vacuum(no restrictiction don't need bigger carb.)
I ran that 650 dp for a year and a half. My only other choice i had on hand was a 850 demon carb(basicly a holley carb)
One day i bought a kit, rebuilt my 850 and jetted it for my attitude. The carb ran better all the way thru the power range, with a better et to boot. I real thought the 850 would drown it or bog causing me to do some squirter changes to make it work. didn't have to change anything but my jet side. It even 60 foots better than the 650
Disadvantage of the 850????? the 650 is a better street carb as it sips fuel better
my car travels on a car trailer everywhere it goes.....850 stays on.
Man i can't wait for the snow to get the he ll out of here.
Your car probably really liked that Demon because Demons are torches normally--deadly lean. J.Rob
SLOPAR72
Well-Known Member
It's a challenge to get a carb too lean, at 6600 feet!
That's why i built my eng to build torque down low........Not much air to breath up here, and is why i thought the 850 was going to be too big....but it likes it!
SLOPAR72
Well-Known Member
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