Another Hemi bites the dust!!!

[CrAzYMoPaRGuY]

I don't know about the dual carbs on a Mopar.  I am 47.  My roomate at Georgia Tech had a 69 Charger with a worked 440 and dual Carter AFBs with mechanical secondaries.  It took him ten minutes to get the car started on a 40 degree morning.  "Wah-Wah-Wah-Wah-Wah ... rump-rump... stall" repeated 20 times.  His car was fast as bat out of hell at highway speeds, but as it had too little vacuum at normal rpms, it was a responsive as an old dog with 3 legs when he first nailed the gas.

<{POST_SNAPBACK}>

 

Here- Tell your room mate to take off the air cleaners, and look down the carbs when trying an initial "cold start".

My money is on an accelerator pump that is dry. The engine will not start until the pump fills the carb's bowls enough to allow the pumps to squirt.

 

Add an electric pump to prime the carbs in the morning, the cold start problem will be SOLVED I'm willing to bet.

 

I'm willing to bet the tuning on the car was non-existant by the sounds of the performance. As for the Carters, the stepped metering rods are controlled by vacuum, did he know what he was doing when he set it up?

What about timing, distributor curve etc?

 

I drove my Demon in the middle of winter, -14 degrees Celcius, it started right up with a tunnel rammed 2x4bbl 440 and it would have a strong idle within 30 seconds. It drove away cold with no flatspots or hesitation. Two 450cfm Holleys on an M1 tunnel ram, 484/284 cam, 10.5 to 1 compression.

And I'm not a tuning guru.....

[zippy]

the fouling plugs issue is also part of the tuning issue i'm referring to. this info wasn't from just one or two people. more than likely the cause for the plug fouling conditions that they experienced themselves or knew of from other cars were the result of a poorly tuned ride. by poorly tuned that also apply's to having the valves adjusted proplerly, points in good condition with proper dwell (yes, i even own a dwell meter for working on such old boys), and timing set. i know of some idiots that would drive around with the timing turned way down on their ride to get that rough idle cam sound. i'd like to think this wasn't the case with the hemi's i've heard of, but for whatever reason someone would drive their car around without it in best tune and ready for a race is beyond me. with the carburation, cam size, and cylinder head design it's not something that would suprise me. you have a big bore and short stroke engine that has huge valve and port sizing and most often plenty of carburation to match. drive that car around with the timing a few degrees retarded and it's not going to like life much in traffic. this all with only about a 20k voltage ignition system. there were many engines in the late 60's and early 70's that probably experienced this problem such as the terribly designed boss 302. i do agree with the hemi being out of it's designed range. the 426 version was built with the intention of performance, not crusing and gettng to the corner store. for the most part i am an antichrysler, but i can admit i'd like to go out for a spin in a hemi dart or 70 cuda wtih 4.10 gear, 4 speed, dana 60, and sure grip rear (in plumb crazy purple thank you...)

[zippy]

thinking of mopars. we have a small mopar grouping around my town. they all know me from around. one of them has a half ton d100 or something like that. that truck he's shooting for 9's with this year and drives it on the street still on pump gas. i'll see if i can dig up a picture of that truck. then there is Bill Dekeip and his challenger. (picture below). of course of any mopar guy you can't leave out Vance Cummins.

 

[CrAzYMoPaRGuY]

for the most part i am an antichrysler

 

Realllllly? I couldn't tell.....!

 

A poorly tuned engine with retarded timing is a poorly tuned engine with retarded timing. Hemi, small block Chevy, or Ford Cammer, it doesn't matter.

 

The 302 Boss wasn't a "terribly designed" engine, I wonder if you know them well, intended usage etc? The Ford guys sure think of them highly? ;)

 

A stock Hemi was well suited to drive to the corner store, if you were a true gearhead. The only ones that would be a handful were the 1964/1965 versions, they were a little "much" for the street?

 

Try growing up 30 years before you did, and pull a choke every day to try to get your 3 year old car started.

It was a completely different world IMO...?

[CrAzYMoPaRGuY]

thinking of mopars. we have a small mopar grouping around my town. they all know me from around. one of them has a half ton d100 or something like that. that truck he's shooting for 9's with this year and drives it on the street still on pump gas. i'll see if i can dig up a picture of that truck. then there is Bill Dekeip and his challenger. (picture below). of course of any mopar guy you can't leave out Vance Cummins.

 

<{POST_SNAPBACK}>

 

I know the Challenger well, but the truck sure sounds funky!

 

Can I say that on the internet?

"Funky"....?

[zippy]

the guy with the ram is a buddy of bill's. his name is mark. the truck looks pretty cool. (for a dodge) it's painted viper gts blue with white racing stripes.

 

 

that poor ford 302 boss. enough cylinder head port and valve sizing to spin to 8500 and enough cam to spin to 5200. between the two you get an engine that takes up most of the engine bay and yet runs sub par 14's in the quarter.

[CrAzYMoPaRGuY]

Trouble is 14s were the norm for most muscle cars?

 

I'm willing to bet an SRT4 could put a whopping on almost ANY muscle car from the 60s/70s. Only a handful could beat it I bet.

 

Many guys I talk to who are older do the "my 1970 car dead stock pulled the wheels" claims, but it's a foggy memory for sure.

Take a 2005 GTO for a drive and then a 1965 GTO, and tell me the two are comparable?

 

It's kinda sad.

[zippy]

lol, i agree with you fully. an srt-4 taken back in time would be a street warrior. on the other hand, i assume you're familier with all the work they put into making the 302 a "boss". not only was it a very expensive engine setup, but the car was something special too. with 1970 being the cubic inch year, a 302 wasn't what you brought to the party for a special edition car. the 429 wasn't a ton better. the 455's in the buick's and pontiac's for that year in family type cars would clean the clock of the "boss" 302 car. if i recall the 340 for that year was almost a half second quicker in the quarter and with a much less complicated anything to it.

[CrAzYMoPaRGuY]

lol, i agree with you fully. an srt-4 taken back in time would be a street warrior. on the other hand, i assume you're familier with all the work they put into making the 302 a "boss". not only was it a very expensive engine setup, but the car was something special too. with 1970 being the cubic inch year, a 302 wasn't what you brought to the party for a special edition car. the 429 wasn't a ton better. the 455's in the buick's and pontiac's for that year in family type cars would clean the clock of the "boss" 302 car. if i recall the 340 for that year was almost a half second quicker in the quarter and with a much less complicated anything to it.

<{POST_SNAPBACK}>

 

What was the Trans Am series displacement limit? I think it was around 305 cubic inch... The engine couldn't be built bigger, and it was intended to run huge rpms?

[misterp]

CMG - Yup 305; that basically killed Pontiac's days in the Trans Am series, they could not get a destroked Pontiac to breathe right.

 

Zippy - Yup, I have a 428 +.030 with 421SD forged bottom end in my Firebird; it's a real torque monster!

 

Mr. P.

[zippy]

that 305 cubic inch rule made it a pain for a few. the 303 that pontiac used ran pretty hard, but oiling and overall power just weren't there for it.

[I CORNER]

I don't know about the dual carbs on a Mopar.  I am 47.  My roomate at Georgia Tech had a 69 Charger with a worked 440 and dual Carter AFBs with mechanical secondaries.  It took him ten minutes to get the car started on a 40 degree morning.  "Wah-Wah-Wah-Wah-Wah ... rump-rump... stall" repeated 20 times.  His car was fast as bat out of hell at highway speeds, but as it had too little vacuum at normal rpms, it was a responsive as an old dog with 3 legs when he first nailed the gas.

<{POST_SNAPBACK}>

 

Here- Tell your room mate to take off the air cleaners, and look down the carbs when trying an initial "cold start".

My money is on an accelerator pump that is dry. The engine will not start until the pump fills the carb's bowls enough to allow the pumps to squirt.

 

Add an electric pump to prime the carbs in the morning, the cold start problem will be SOLVED I'm willing to bet.

 

I'm willing to bet the tuning on the car was non-existant by the sounds of the performance. As for the Carters, the stepped metering rods are controlled by vacuum, did he know what he was doing when he set it up?

What about timing, distributor curve etc?

 

I drove my Demon in the middle of winter, -14 degrees Celcius, it started right up with a tunnel rammed 2x4bbl 440 and it would have a strong idle within 30 seconds. It drove away cold with no flatspots or hesitation. Two 450cfm Holleys on an M1 tunnel ram, 484/284 cam, 10.5 to 1 compression.

And I'm not a tuning guru.....

<{POST_SNAPBACK}>

 

Well as I said, I am 47 and that was a long time ago. I was referring to my roomate in the year 1977 and he is probably dead by now as he was a heavy smoker. His Carter AFBs had mechanical not vacuum secondaries, so it really bogged down, ... progressive metering rods or not, he had no vacuum.

 

2 years after that I remembered his lack of throttle response and stuck with a vacuum secondary carburetor. I used an 800 CFM 1974 Super Duty 455 Quadrajet on my rebuilt 30-over Pontiac 455 with 4-bolt mains, BME aluminum rods, Moldex crank, forged pistons, ported Ram Air 3 heads, Ram Air 4 intake and cam. The car started immediately with no choke on 30 degree mornings, yet still pulled hard past 6500 rpm. It made so much power without hesitation cold that I had to make sure I kept my foot out of it until the oil warmed up for fear of spinning the large journal bearings (common problem with Pontiacs).

[CrAzYMoPaRGuY]

I don't know about the dual carbs on a Mopar.  I am 47.  My roomate at Georgia Tech had a 69 Charger with a worked 440 and dual Carter AFBs with mechanical secondaries.  It took him ten minutes to get the car started on a 40 degree morning.  "Wah-Wah-Wah-Wah-Wah ... rump-rump... stall" repeated 20 times.  His car was fast as bat out of hell at highway speeds, but as it had too little vacuum at normal rpms, it was a responsive as an old dog with 3 legs when he first nailed the gas.

<{POST_SNAPBACK}>

 

Here- Tell your room mate to take off the air cleaners, and look down the carbs when trying an initial "cold start".

My money is on an accelerator pump that is dry. The engine will not start until the pump fills the carb's bowls enough to allow the pumps to squirt.

 

Add an electric pump to prime the carbs in the morning, the cold start problem will be SOLVED I'm willing to bet.

 

I'm willing to bet the tuning on the car was non-existant by the sounds of the performance. As for the Carters, the stepped metering rods are controlled by vacuum, did he know what he was doing when he set it up?

What about timing, distributor curve etc?

 

I drove my Demon in the middle of winter, -14 degrees Celcius, it started right up with a tunnel rammed 2x4bbl 440 and it would have a strong idle within 30 seconds. It drove away cold with no flatspots or hesitation. Two 450cfm Holleys on an M1 tunnel ram, 484/284 cam, 10.5 to 1 compression.

And I'm not a tuning guru.....

<{POST_SNAPBACK}>

 

Well as I said, I am 47 and that was a long time ago. I was referring to my roomate in the year 1977 and he is probably dead by now as he was a heavy smoker. His Carter AFBs had mechanical not vacuum secondaries, so it really bogged down, ... progressive metering rods or not, he had no vacuum.

 

2 years after that I remembered his lack of throttle response and stuck with a vacuum secondary carburetor. I used an 800 CFM 1974 Super Duty 455 Quadrajet on my rebuilt 30-over Pontiac 455 with 4-bolt mains, BME aluminum rods, Moldex crank, forged pistons, ported Ram Air 3 heads, Ram Air 4 intake and cam. The car started immediately with no choke on 30 degree mornings, yet still pulled hard past 6500 rpm. It made so much power without hesitation cold that I had to make sure I kept my foot out of it until the oil warmed up for fear of spinning the large journal bearings (common problem with Pontiacs).

<{POST_SNAPBACK}>

 

His Carter AFBs had an air door over the secondaries, did they not?

Did you ever check the vacuum of the engine, and if you did, where was the reading taken from?

 

Did your Pontiac have some sort of heat soak gasket on it, a thick GM stock style gasket or phenolic gasket?

 

My buddy has smoked like a chimney since he was a teen, he's still going strong after decades.

He's a complete alchoholic too!

[I CORNER]

I don't know about the dual carbs on a Mopar.  I am 47.  My roomate at Georgia Tech had a 69 Charger with a worked 440 and dual Carter AFBs with mechanical secondaries.  It took him ten minutes to get the car started on a 40 degree morning.  "Wah-Wah-Wah-Wah-Wah ... rump-rump... stall" repeated 20 times.  His car was fast as bat out of hell at highway speeds, but as it had too little vacuum at normal rpms, it was a responsive as an old dog with 3 legs when he first nailed the gas.

<{POST_SNAPBACK}>

 

Here- Tell your room mate to take off the air cleaners, and look down the carbs when trying an initial "cold start".

My money is on an accelerator pump that is dry. The engine will not start until the pump fills the carb's bowls enough to allow the pumps to squirt.

 

Add an electric pump to prime the carbs in the morning, the cold start problem will be SOLVED I'm willing to bet.

 

I'm willing to bet the tuning on the car was non-existant by the sounds of the performance. As for the Carters, the stepped metering rods are controlled by vacuum, did he know what he was doing when he set it up?

What about timing, distributor curve etc?

 

I drove my Demon in the middle of winter, -14 degrees Celcius, it started right up with a tunnel rammed 2x4bbl 440 and it would have a strong idle within 30 seconds. It drove away cold with no flatspots or hesitation. Two 450cfm Holleys on an M1 tunnel ram, 484/284 cam, 10.5 to 1 compression.

And I'm not a tuning guru.....

<{POST_SNAPBACK}>

 

Well as I said, I am 47 and that was a long time ago. I was referring to my roomate in the year 1977 and he is probably dead by now as he was a heavy smoker. His Carter AFBs had mechanical not vacuum secondaries, so it really bogged down, ... progressive metering rods or not, he had no vacuum.

 

2 years after that I remembered his lack of throttle response and stuck with a vacuum secondary carburetor. I used an 800 CFM 1974 Super Duty 455 Quadrajet on my rebuilt 30-over Pontiac 455 with 4-bolt mains, BME aluminum rods, Moldex crank, forged pistons, ported Ram Air 3 heads, Ram Air 4 intake and cam. The car started immediately with no choke on 30 degree mornings, yet still pulled hard past 6500 rpm. It made so much power without hesitation cold that I had to make sure I kept my foot out of it until the oil warmed up for fear of spinning the large journal bearings (common problem with Pontiacs).

<{POST_SNAPBACK}>

 

His Carter AFBs had an air door over the secondaries, did they not?

Did you ever check the vacuum of the engine, and if you did, where was the reading taken from?

 

Did your Pontiac have some sort of heat soak gasket on it, a thick GM stock style gasket or phenolic gasket?

 

My buddy has smoked like a chimney since he was a teen, he's still going strong after decades.

He's a complete alchoholic too!

<{POST_SNAPBACK}>

 

He had a very radical cam in that engine, which had a very low vacuum at idle. He told me that they had mechanical secondaries so that ALL butterflies opened at WOT and it sure felt like it. If I recall correctly, he indicated that they were 600CFM Carter AFBs. Are there more than 1 size AFB?

 

The dual-plane Pontiac Ram Air IV intake used a separate cast iron crossover for the choke which I omitted and blocked off the heat riser ports. Of course the Pontiac intakes were separated from the lifter gallery, so hot oil did not splash and heat up the intake. I also used an aluminum heat dissipator plate between the carb and intake which had a thick gasket on both sides of the plate. It worked pretty well to keep the carb cool, but I was surprised that how easily it started in cold weather.

[misterp]

...

The dual-plane Pontiac Ram Air IV intake used a separate cast iron crossover for the choke which I omitted and blocked off the heat riser ports.  Of course the Pontiac intakes were separated from the lifter gallery, so hot oil did not splash and heat up the intake.  I also used an aluminum heat dissipator plate between the carb and intake which had a thick gasket on both sides of the plate.  It worked pretty well to keep the carb cool, but I was surprised that how easily it started in cold weather.

You mean one of these :

 

 

This is a pic of the RA/HO/SD manifold on my Firebird; the intake is factory aluminum, the crossover is a separate cast-iron piece and runs a good 1/2-inch below the bottom of the intake and its sole purpose is to hold the choke coil! I decided to run an electric choke instead, I am also using the *factory* GM heat dissapator plate. I had the exhaust crossovers filled on my Pontiac heads as well but still bolted-up the crossover for show... the engine has so much torque that cold-idle manners are *not* an issue, it doesn't need the exhaust crossover. These intakes build fantastic low-end grunt but do not breathe well over 5000-rpm (worse than cast iron Pontiac intakes), I will sell mine when I redo the top-end of the engine. Someday...

 

And not all Quadrajets are made alike; the SD-455 and RA-400 QJet carbs are very special limited pieces. The 70-78 400-T/A QJets are similar and can be made into great hot street carbs, too. Most of the other QJet models are not suited for performance use at all. The one I am using is a modified 77 T/A model and I really love it. The only carb I have run (so far) that has been the same or better is a BG Demon.

 

Mr. P.