Pros & Cons of a Tri-power vs 4 barrel?
04-08-2007, 11:20 PM
#61
Race Director
GOOD CHOICE! I here their tech support is real helpful to dial it in too.
04-09-2007, 08:26 AM
#62
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If you have any questions, shoot us PM and we'll be happy to help you out anytime!
Technical Support,
Barry Grant, Inc.
www.barrygrant.com
04-09-2007, 11:33 AM
#63
Le Mans Master
It's a moot point now but....
Plus...
Originally Posted by 63mako
".... I would think they are different from the 400 hp vs the 435 hp as well as the accelerator pumps, jets and maybe the power valve. "
Those parts are the same for the 400 & 435 HP engines.
Plus...
Originally Posted by 63mako
".... I would think they are different from the 400 hp vs the 435 hp as well as the accelerator pumps, jets and maybe the power valve. "
Those parts are the same for the 400 & 435 HP engines.
04-10-2007, 10:52 PM
#64
Burning Brakes
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Well here's the update, I installed the BG BBC Sixshooter today. This was my first intake/carb install to be honest...go ahead 
now....this is how it went.
... so I am not sure if it is just me or if the machining is a bit off, but the intake holes were not lining up exactly, using a rubber hammer tapping it one way or the other slighty was almost futile, it eventually went on, but a very tight fit, especially at the #3, 7, 9, 12 hole.
The bolts will not seat flush at the #11 and 9 hole, they are torqued correctly and threaded in correctly, but not flush, which I wonder if they are really torqued correctly.
Is torque still accurate if you use extension and universal joint?
I had to do that for the #5 and 9, just curious if their torqued right too.
Unless I'm blind, the instructions do not say where the spring goes and I don't see it in the pictures, if anyone knows?
Instructions said RTV and Loc-Tite were included...I received neither, and for some reason the screws for the aircleaner lid to carb plates are too big, I mean there is no way these will fit.
Everything else looks really good.
So I have to call Jegs tomorrow
And probably BG if no one here knows where that spring goes.
Thanks
now....this is how it went.... so I am not sure if it is just me or if the machining is a bit off, but the intake holes were not lining up exactly, using a rubber hammer tapping it one way or the other slighty was almost futile, it eventually went on, but a very tight fit, especially at the #3, 7, 9, 12 hole.
The bolts will not seat flush at the #11 and 9 hole, they are torqued correctly and threaded in correctly, but not flush, which I wonder if they are really torqued correctly.
Is torque still accurate if you use extension and universal joint?
I had to do that for the #5 and 9, just curious if their torqued right too.
Unless I'm blind, the instructions do not say where the spring goes and I don't see it in the pictures, if anyone knows?
Instructions said RTV and Loc-Tite were included...I received neither, and for some reason the screws for the aircleaner lid to carb plates are too big, I mean there is no way these will fit.
Everything else looks really good.
So I have to call Jegs tomorrow
And probably BG if no one here knows where that spring goes.Thanks
Last edited by 1ARACE; 04-10-2007 at 11:57 PM.
04-11-2007, 09:24 AM
#65
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... so I am not sure if it is just me or if the machining is a bit off, but the intake holes were not lining up exactly, using a rubber hammer tapping it one way or the other slighty was almost futile, it eventually went on, but a very tight fit, especially at the #3, 7, 9, 12 hole.
The bolts will not seat flush at the #11 and 9 hole, they are torqued correctly and threaded in correctly, but not flush, which I wonder if they are really torqued correctly.
Is torque still accurate if you use extension and universal joint?
I had to do that for the #5 and 9, just curious if their torqued right too.
Unless I'm blind, the instructions do not say where the spring goes and I don't see it in the pictures, if anyone knows?
Instructions said RTV and Loc-Tite were included...I received neither, and for some reason the screws for the aircleaner lid to carb plates are too big, I mean there is no way these will fit.
Everything else looks really good.
So I have to call Jegs tomorrow And probably BG if no one here knows where that spring goes.
Thanks
The bolts will not seat flush at the #11 and 9 hole, they are torqued correctly and threaded in correctly, but not flush, which I wonder if they are really torqued correctly.
Is torque still accurate if you use extension and universal joint?
I had to do that for the #5 and 9, just curious if their torqued right too.
Unless I'm blind, the instructions do not say where the spring goes and I don't see it in the pictures, if anyone knows?
Instructions said RTV and Loc-Tite were included...I received neither, and for some reason the screws for the aircleaner lid to carb plates are too big, I mean there is no way these will fit.
Everything else looks really good.
So I have to call Jegs tomorrow
And probably BG if no one here knows where that spring goes.Thanks
Sorry about the troubles you had. Curious were your heads or block ever cut? Bolt fitment is not an issue we've heard before, but we'll let the guys in our machine shop know.
Are the screws for the D-Rings for the air cleaner base the wrong diameter or length?
If you'll give us your address we can get the missing / wrong components replaced for you.
The return spring should go from the bottom of the linkage arm on the center carburetor to the accelerator pump arm stud of the rear carburetor.
Technical Support,
Barry Grant, Inc.
www.barrygrant.com
04-11-2007, 10:51 AM
#66
Burning Brakes
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Location: Lima, OH -- 69 L71 427/435hp
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You've got a PM
Sorry about the troubles you had. Curious were your heads or block ever cut? Bolt fitment is not an issue we've heard before, but we'll let the guys in our machine shop know.
Are the screws for the D-Rings for the air cleaner base the wrong diameter or length?
If you'll give us your address we can get the missing / wrong components replaced for you.
The return spring should go from the bottom of the linkage arm on the center carburetor to the accelerator pump arm stud of the rear carburetor.
Technical Support,
Barry Grant, Inc.
www.barrygrant.com
Sorry about the troubles you had. Curious were your heads or block ever cut? Bolt fitment is not an issue we've heard before, but we'll let the guys in our machine shop know.
Are the screws for the D-Rings for the air cleaner base the wrong diameter or length?
If you'll give us your address we can get the missing / wrong components replaced for you.
The return spring should go from the bottom of the linkage arm on the center carburetor to the accelerator pump arm stud of the rear carburetor.
Technical Support,
Barry Grant, Inc.
www.barrygrant.com
The screw diameter is too big for the holes in the air cleaner lid, or else the screws are right and the air cleaner lid holes are too small, one of the two. I can self tap the screws I have now through the D-Rings, but not through lid.
I'm using orginal block and heads, they only have about 15-20k mile use on them, I did not see any machining nor did the machine shop notice any machining done to them.
I started off following bolt pattern in instructions, but after the first 3-4 bolts, using a drop light I could see the #9, 10 was off a hair (bolt wouldn't start straight) then I tap it, and then the 5, 7, 8 would be off a hair.
Thanks for spring location also
PM sent.
Thanks again for the information and helpfulness, is much appreciated
05-05-2007, 06:27 PM
#67
Burning Brakes
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Location: Lima, OH -- 69 L71 427/435hp
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Yes, we have customers with them under stock hoods.
Technical Support,
Barry Grant, Inc.
www.barrygrant.com
Technical Support,
Barry Grant, Inc.
www.barrygrant.com
05-05-2007, 07:48 PM
#68
Le Mans Master
I've had three Tri-Power setups over the years on different BB's, and found the stories that they are difficult to properly tune to be complete propaganda. Besides, "three duces" just exude coolness when you pop the hood for curious onlookers.
On the plus side, when set up correctly, 3x2's can be very economical to operate while still offering more cfm flow capacity than most BB's will ever need. However, Chevy never designed an adequate (read "high-rise") manifold on which to place all that awe inspiring carburetion, and the system never had a chance to live up to its true potential. (If there is a good 3x2, rect. port high-rise out there, someone let me know!)
That said, despite my fondness for multi-carbs, a single, large 4-barrel will crown the BB in my C3 when it rises again. But, I'll always have a soft spot for the Tri-Power...
On the plus side, when set up correctly, 3x2's can be very economical to operate while still offering more cfm flow capacity than most BB's will ever need. However, Chevy never designed an adequate (read "high-rise") manifold on which to place all that awe inspiring carburetion, and the system never had a chance to live up to its true potential. (If there is a good 3x2, rect. port high-rise out there, someone let me know!)
That said, despite my fondness for multi-carbs, a single, large 4-barrel will crown the BB in my C3 when it rises again. But, I'll always have a soft spot for the Tri-Power...
05-07-2007, 01:36 PM
#69
Melting Slicks
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Hi
Now having driven my 68 with the 435 HP Tripower setup for a little while, I can only say that it is a very smooth running setup with endless power.
Idles always correct, doesn't bog when braking hard or accellerating hard.
Very different to my previously installed 650' CFM DP Holley.
If I could only find a method to get the filter attached to the hood ( L88 type induction system, may be ) in order to see this setup when opening the hood. Too much is burried under the triangle air filter.
Günther
Now having driven my 68 with the 435 HP Tripower setup for a little while, I can only say that it is a very smooth running setup with endless power.
Idles always correct, doesn't bog when braking hard or accellerating hard.
Very different to my previously installed 650' CFM DP Holley.
If I could only find a method to get the filter attached to the hood ( L88 type induction system, may be ) in order to see this setup when opening the hood. Too much is burried under the triangle air filter.
Günther
05-07-2007, 03:17 PM
#70
Burning Brakes
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I think you will always get comments from folks that do not run multiple carbs ,,,, giving them a bad rap . Multiples are very driveable and give great performance .
Geo
Geo
12-17-2018, 12:48 PM
#72
Le Mans Master
Do you have proof or is it written in paper by a scientist? The tri power had 1,230 CFMs more then a 4 barrel and just about dual quad intake. I think your logic is because its three 2 barrel carbs it's not feeding the engine enough, How about a Holly 3 Barrel with 950 CFMs. Usually the ones who bad mouth something is mostly jealous and cant afford, so will make up lies so other people follow in your path. I've had one on my small block Chevy without any issues and what because your running of the middle carb your not providing enough fuel until you kick it in? A 4 barrel also runs on 2 barrels until you kick it in. I haven't seen none if theory supporting how bad it is? You want to hear the ultimate engine for Chevrolet? Try a Big Block LS7 or Even the ZL1 with the Tri power on it. The 70 Chevelle SS with the 454 LS6 should have came with the Tri power, that would have been one bad ride to this date. I never seen factory Dual quads on the Big Block 65 threw 74 cars but Dodge and Ford there big blocks with dual quads, the only dual quad was on the 69 Cross ram 302 Z28 and you had to buy that special for racing. So I see nothing wrong with the Tri Power set ups.
Anyway, couple of issues with your numbers. 2bbl carbs are not rated the safe as 4 bbl carbs. The correction factor is 1.414. So 1230 cfm of total 3x2 flow is equal to ~870 cfm of 4bbl flow. Add in manifold distribution and an modern 4bbl will make more power and be easier to tune than the 3x2.
I have run both vacuum secondary (stock carbs) and mechanical secondary (Mopar aftermarket carbs) on a 3x2 on my 496 big block. Both were fun. The mechanical secondary was lots of fun to drive. But to get them tuned in right required multiple sessions with a wideband A/F setup.
I am now running a custom 3x2 port injected EFI setup. I could probably make more power with a good 4bbl EFI but it looks cool and fits under my stock hood.
ON EDIT: A poster with 2 posts accusing Lars of making up lies.
: Lars has contributed immensely to this board over the last 15+ years and has the background and knowledge to speak to this and many other issues.
Last edited by SteveG75; 12-17-2018 at 12:50 PM.
The following 2 users liked this post by SteveG75:
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12-17-2018, 03:52 PM
#73
Melting Slicks
Holy thread resurrection BATMAN. 11-1/2 years...
Anyway, couple of issues with your numbers. 2bbl carbs are not rated the safe as 4 bbl carbs. The correction factor is 1.414. So 1230 cfm of total 3x2 flow is equal to ~870 cfm of 4bbl flow. Add in manifold distribution and an modern 4bbl will make more power and be easier to tune than the 3x2.
ON EDIT: A poster with 2 posts accusing Lars of making up lies.: Lars has contributed immensely to this board over the last 15+ years and has the background and knowledge to speak to this and many other issues.
Anyway, couple of issues with your numbers. 2bbl carbs are not rated the safe as 4 bbl carbs. The correction factor is 1.414. So 1230 cfm of total 3x2 flow is equal to ~870 cfm of 4bbl flow. Add in manifold distribution and an modern 4bbl will make more power and be easier to tune than the 3x2.
ON EDIT: A poster with 2 posts accusing Lars of making up lies.
: Lars has contributed immensely to this board over the last 15+ years and has the background and knowledge to speak to this and many other issues. What he said.Mike
12-17-2018, 05:13 PM
#75
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Do you have proof or is it written in paper by a scientist? The tri power had 1,230 CFMs more then a 4 barrel and just about dual quad intake. I think your logic is because its three 2 barrel carbs it's not feeding the engine enough, How about a Holly 3 Barrel with 950 CFMs. Usually the ones who bad mouth something is mostly jealous and cant afford, so will make up lies so other people follow in your path. I've had one on my small block Chevy without any issues and what because your running of the middle carb your not providing enough fuel until you kick it in? A 4 barrel also runs on 2 barrels until you kick it in. I haven't seen none if theory supporting how bad it is? You want to hear the ultimate engine for Chevrolet? Try a Big Block LS7 or Even the ZL1 with the Tri power on it. The 70 Chevelle SS with the 454 LS6 should have came with the Tri power, that would have been one bad ride to this date. I never seen factory Dual quads on the Big Block 65 threw 74 cars but Dodge and Ford there big blocks with dual quads, the only dual quad was on the 69 Cross ram 302 Z28 and you had to buy that special for racing. So I see nothing wrong with the Tri Power set ups.
I am a scientist, and yes, I've written several papers.That's pretty funny, Jack - thanks!
Lars
Last edited by lars; 12-17-2018 at 10:40 PM.
12-17-2018, 06:47 PM
#77
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Jim -
The wideband testing and dyno tuning I've done on the stock Tripowers usually shows that they run rich, especially on the center carb. You might want to buy, beg, borrow or steal a wideband setup that can be stuck up your exhaust and see if the center needs to be leaned out a tad. Make sure the float level is not too high, set the idle mixture screws to the leanest setting that still produces a good quality idle (idle mixture setting will affect cruise mixture on a Tripower), and verify your jetting is not richer than stock. But first, make sure your timing is set up right - you need to be running 36 to 38 total timing with initial in the mid teens, and with a working vacuum advance hooked up to manifold vacuum pulling in not more than 12 degrees of vacuum advance, giving you actual timing at idle of about 30 degrees.This setup will get you running pretty nicely. Drop me an e-mail if you need specific info.
Lars
The wideband testing and dyno tuning I've done on the stock Tripowers usually shows that they run rich, especially on the center carb. You might want to buy, beg, borrow or steal a wideband setup that can be stuck up your exhaust and see if the center needs to be leaned out a tad. Make sure the float level is not too high, set the idle mixture screws to the leanest setting that still produces a good quality idle (idle mixture setting will affect cruise mixture on a Tripower), and verify your jetting is not richer than stock. But first, make sure your timing is set up right - you need to be running 36 to 38 total timing with initial in the mid teens, and with a working vacuum advance hooked up to manifold vacuum pulling in not more than 12 degrees of vacuum advance, giving you actual timing at idle of about 30 degrees.This setup will get you running pretty nicely. Drop me an e-mail if you need specific info.
Lars
Last edited by lars; 12-17-2018 at 10:46 PM.
12-18-2018, 07:47 AM
#78
Drifting
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2018 C3 of Year Finalist
Timming
Lars,
thanks for the reply. I rebuilt the center carb then took it to a local rebuilder to run a test on it
for me . He said it was fine so I put it back on again but I don’t know what size jets are in it.
my biggest trouble was it would not idle. So finally I took someone’s advice and pushed the
distributor around a little till I heard a pinging and then backed it off. The car has ac with
power steering and an I idler pulley. It is almost impossible to see the degree gauge . Do
you know a trick for this? Now the car idles great even with the ac on but the mileage is
really bad. The next nice day I will get it out and try again with the timming that must be it.
i am pretty sure the float level is ok too. There is no gas smell in the garage anyway.
i see some people here say their car gets good gas mileage so there must be an answer
to this. The car has been completely restored and the numbers matching engine has been
rebuilt. I have your paper from 6 months ago so I will have to try harder to set timming.
thanks again
Jim
thanks for the reply. I rebuilt the center carb then took it to a local rebuilder to run a test on it
for me . He said it was fine so I put it back on again but I don’t know what size jets are in it.
my biggest trouble was it would not idle. So finally I took someone’s advice and pushed the
distributor around a little till I heard a pinging and then backed it off. The car has ac with
power steering and an I idler pulley. It is almost impossible to see the degree gauge . Do
you know a trick for this? Now the car idles great even with the ac on but the mileage is
really bad. The next nice day I will get it out and try again with the timming that must be it.
i am pretty sure the float level is ok too. There is no gas smell in the garage anyway.
i see some people here say their car gets good gas mileage so there must be an answer
to this. The car has been completely restored and the numbers matching engine has been
rebuilt. I have your paper from 6 months ago so I will have to try harder to set timming.
thanks again
Jim
12-18-2018, 11:32 AM
#79
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Correct timing has a huge effect on gas mileage. You cannot set the timing "by ear" or by the "ping point" and get it anywhere close. Yes, it's difficult to get a straight visual shot at the timing tab on that engine, but if you get in there pretty close to the engine fan, there is a very small "sight window" where you can just barely catch a glimpse of the tab and balancer. You'll need a dial-back timing light.
I do have capability to test and set up that center carb if you want me to do a checkout on it for you.
Lars
I do have capability to test and set up that center carb if you want me to do a checkout on it for you.
Lars
12-18-2018, 05:45 PM
#80
Drifting
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Thanks for the reply Lars,I do have a dial back timming light and will try that again but I may
take you up on the offer to check out this center carb. Might be a good idea . You could check out the
jets and make sure they are right.. I will get back to you after Christmas. Thanks again and
merry Christmas to you.
Jim
take you up on the offer to check out this center carb. Might be a good idea . You could check out the
jets and make sure they are right.. I will get back to you after Christmas. Thanks again and
merry Christmas to you.
Jim
