Thanks! I'm probably going to go with the 350 or 400 block, post 68' as I believe that most of the 327 blocks were pre-67'.
Stumbles on takeoff
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
And we've got to give kudos to Jig-a-Low and Todd for their great perspectives as well, thanks guys!
PS: Todd, love the specs on your motor and that's what I'm looking to build in the future, something along the lines of about 300 hp. I'm curious as to the 331 Cu In. on that puppy. What bore stroke and block did you use to come up with that? What was your reasoning? I'd like to know! Kind of like the 377 cu in, which is a 400 block, with the 350 rods, versus the other way around (I'm still learning from the Chevy Interchange Manual, so correct me if I'm wrong, here.)
PS: Todd, love the specs on your motor and that's what I'm looking to build in the future, something along the lines of about 300 hp. I'm curious as to the 331 Cu In. on that puppy. What bore stroke and block did you use to come up with that? What was your reasoning? I'd like to know! Kind of like the 377 cu in, which is a 400 block, with the 350 rods, versus the other way around (I'm still learning from the Chevy Interchange Manual, so correct me if I'm wrong, here.)
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
And we've got to give kudos to Jig-a-Low and Todd for their great perspectives as well, thanks guys!
PS: Todd, love the specs on your motor and that's what I'm looking to build in the future, something along the lines of about 300 hp. I'm curious as to the 331 Cu In. on that puppy. What bore stroke and block did you use to come up with that? What was your reasoning? I'd like to know! Kind of like the 377 cu in, which is a 400 block, with the 350 rods, versus the other way around (I'm still learning from the Chevy Interchange Manual, so correct me if I'm wrong, here.)
PS: Todd, love the specs on your motor and that's what I'm looking to build in the future, something along the lines of about 300 hp. I'm curious as to the 331 Cu In. on that puppy. What bore stroke and block did you use to come up with that? What was your reasoning? I'd like to know! Kind of like the 377 cu in, which is a 400 block, with the 350 rods, versus the other way around (I'm still learning from the Chevy Interchange Manual, so correct me if I'm wrong, here.)
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
Wow I cannot believe it!! I removed one plug after a 3 mile ride ,completely white not a trace of black or tan. The addition of long tube headers and side pipes and 1.6 roller rockers thru the A/F mixture out of wack.needless to say stumble and then runs. I been told to checked carb. To manifold gasket should be 4 holes not open or the type with no separation between primary and secondary??? I guess I have to go up at least 4 jet/squirted size under circumstances. Thank you Bob
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Wow I cannot believe it!! I removed one plug after a 3 mile ride ,completely white not a trace of black or tan. The addition of long tube headers and side pipes and 1.6 roller rockers thru the A/F mixture out of wack.needless to say stumble and then runs. I been told to checked carb. To manifold gasket should be 4 holes not open or the type with no separation between primary and secondary??? I guess I have to go up at least 4 jet/squirted size under circumstances. Thank you Bob
Quadrajet Gasket
If you don't have the Holley Qjet and have the Holley with four holes the exact same size, you need this:
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Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
Removed carb. Gasket is correct as you show on bottom photo ( list 1850-3) I assume that means double pumper.there was a 3/16 hole dead center between the bore holes in gasket new one has no holes.existing jets are 66 I have new 74 from years back also a new power valve number 125-65 incidentally old power valve has small ball on end with spring underneath new one has 3/8" brass washer with center brass rivet/shaft with sping under it.what is your call?
I have parts I think some of you guys might need just postage! In addition to 400" I have bow tie block and mark 4 454 with 10 hours all 4 bolt mains the bow tie is bored o/s.
I have parts I think some of you guys might need just postage! In addition to 400" I have bow tie block and mark 4 454 with 10 hours all 4 bolt mains the bow tie is bored o/s.
Le Mans Master
Joined: Oct 2006
Posts: 6,842
Likes: 285
From: Palmdale CA
Removed carb. Gasket is correct as you show on bottom photo ( list 1850-3) I assume that means double pumper.there was a 3/16 hole dead center between the bore holes in gasket new one has no holes.existing jets are 66 I have new 74 from years back also a new power valve number 125-65 incidentally old power valve has small ball on end with spring underneath new one has 3/8" brass washer with center brass rivet/shaft with sping under it.what is your call?
I have parts I think some of you guys might need just postage! In addition to 400" I have bow tie block and mark 4 454 with 10 hours all 4 bolt mains the bow tie is bored o/s.
I have parts I think some of you guys might need just postage! In addition to 400" I have bow tie block and mark 4 454 with 10 hours all 4 bolt mains the bow tie is bored o/s.
Gawd, I hit my carb knowledge limit on this thread! BTW, how does it run? Couldn't tell if you were happy with it or not.
Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
Did not assemble the carb yet I am waiting for the answer to my question on power valve and jet size before I assemble and install carb. Going From size 66 to 74 would be a enourmous jump but the carb is sooooo' lean it is scary need someone with experience to answer befor I go on stupid trial and error when someone can put me on the right track. Thank again
Last edited by Captain bob; Jan 28, 2013 at 01:28 PM. Reason: Explain clearly
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
so what is the list number, did we confirm you do have a 4776?
did you preset the throttle plates??????? make sure transfer slots are set right.. sooo many people are not familiar, I bet this is what you need to focus on, rather than disconnecting the secondaries...
jet sizes, yeah you can put smaller ones in etc, but a 600 dp df should do fine on that motor...I would take the carb off, preset the transfer slots, also adjust the linkage, I believe it is 12-15 thousanths clearance required for the accelerator pumps. Correct transfer slot adjustment should greatly reduce if not irradicate eye burning rich conditions and and off idle.
I also would not be afraid to put a little bit more in the initial timing, but first off I would make sure the carb is correct - I also have heard on many occasions, you will be able to adjust the idle screws ONLY by the mixture screws...once the transfer slots are preset correctly...imagine getting the car to run and idle perfect via the mixture screws because the transfer slots are perfectly set up
read this:
http://members.tccoa.com/392bird/tuning.htm
and this:
http://forums.holley.com/entry.php?4...uretor-Stumble
did you preset the throttle plates??????? make sure transfer slots are set right.. sooo many people are not familiar, I bet this is what you need to focus on, rather than disconnecting the secondaries...
jet sizes, yeah you can put smaller ones in etc, but a 600 dp df should do fine on that motor...I would take the carb off, preset the transfer slots, also adjust the linkage, I believe it is 12-15 thousanths clearance required for the accelerator pumps. Correct transfer slot adjustment should greatly reduce if not irradicate eye burning rich conditions and and off idle.
I also would not be afraid to put a little bit more in the initial timing, but first off I would make sure the carb is correct - I also have heard on many occasions, you will be able to adjust the idle screws ONLY by the mixture screws...once the transfer slots are preset correctly...imagine getting the car to run and idle perfect via the mixture screws because the transfer slots are perfectly set up
read this:
http://members.tccoa.com/392bird/tuning.htm
and this:
http://forums.holley.com/entry.php?4...uretor-Stumble
Last edited by BOSTONCAMARO; Jan 28, 2013 at 02:15 PM.
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
I didn't touch throttle plate but I will check now. I goggle Holley I have a list 1850-3 which is a 600cfm stock jetted 66 plate is 134-9 power valve is 6.5 .vacuum secondary type 4160.probally would blow a hole in piston if I drove it this lean-------
Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
I have carb. Apart ,first of all accelerator pump arm set at "0" so I change to .015 thousands.changed power valve to a new 6.5 same as old but new next I replaced main jets from 66 to 70. I know the main jets don't take over until 1800 to 2000 rpm but forgetting off the line for a minute she is also running way lean at all speeds plugs are white!i will not play with pump cam because I figured I would fiddle with this once I try with changes.first thing while running check float level again and then go to tach,vacuum gauge on mixture screws.
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
I think, it is like 28 thousandths that we want to see, so it looks like a little square... (just checked, Holley says 25-30)
Example of transfer slots set to about 26 thousandths...a good baseline
<---------------------------------------------------------------------------------------------------------------------------------------->
BELOW Example of transfer slots with too much being exposed...making for a rich condition...
Example of transfer slots set to about 26 thousandths...a good baseline
<---------------------------------------------------------------------------------------------------------------------------------------->
BELOW Example of transfer slots with too much being exposed...making for a rich condition...
Last edited by BOSTONCAMARO; Jan 28, 2013 at 07:22 PM.
Melting Slicks
Joined: May 2006
Posts: 3,303
Likes: 14
From: Lynn MA
when you set the floats and want to check them...shut car off....very gentle bump the car...with your leg, lean on it slightly etc....fuel should just dribble out, once they do this, dribble a tad of fuel when car is bumped with car NOT running...you should be able to run the car and be in a good ballpark float level wise....clear sight plugs also good so you can again take a peek
Thread Starter
Racer
Joined: Jan 2013
Posts: 302
Likes: 2
From: Sayville New york
I bench it with drop light and magnifier glass and set the screw until T- slot appear square , the rest must be done on car. When they refer to secondary idle adjustment screw to set idle are referring to the idle air adjusting screws or is there another way to set idle?