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Starting engine build, which block do I use?


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Well I got in the Christmas spirit and finally pulled the trigger on the engine work.;)

 

This is what the build will consist of:

 

New main, cam, & rod bearings

Flat tappet cam - Duration: 280/290 - 214/224 @.050; Lift: .510/.510; Centerlines: 107/117; LSA: 112

.030 cylinder overbore

Ken Block pistons & rings

Hydraulic lifters

DOAE 4V closed chamber heads

Grind & tap heads for 7/16" stud & PRW Stainless Steel rocker arms

MPG port plates

Pushrods & guides

Valve springs & seats

Double roller timing chain

Oil pump

 

Items I still need to evaluate/research:

-Currently have a Mallory dual point distributor, considering doing the Unilite conversion kit

-I have an Edlebrock Scorpion intake or the stock 4V CJ manifold to choose from initially

-Holley 750 CFM double pumper, needs to be rebuilt

-Headers/exhaust

-C6 transmission with OE stall to be rebuilt this winter/spring

-Unkown rear end gearing; Anybody know the best way to assess what I have installed?

 

I expect to have the engine completed early in the new year. Thanks for any feedback/suggestions.

 

Take the money that the "port plates" cost and put it towards an increased capacity oil pan instead. The Scorpion intake is an unusual piece. Some testing I've read about, by Dan Jones, suggests it works well at least above 4000, but it is almost 2 inches taller than a torquer intake and hood clearance may be a problem. The Edelbrock RPM air gap may be an alternative. If the C6 came from a 351CJ, the stall should be okay. The cam sounds ok but, if you are springing for the studs and guide plates I'd be looking for at least .050 more lift, not more duration, to more effectively use the 4V heads. For gear ratio determination try this method. http://www.differentials.com/technical-help/faqs#What%20gear%20ratio%20do%20I%20have?

Have you researched oiling modifications?

 

Chuck

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Well I got in the Christmas spirit and finally pulled the trigger on the engine work.;)

 

This is what the build will consist of:

 

New main, cam, & rod bearings

Flat tappet cam - Duration: 280/290 - 214/224 @.050; Lift: .510/.510; Centerlines: 107/117; LSA: 112

.030 cylinder overbore

Ken Block pistons & rings

Hydraulic lifters

DOAE 4V closed chamber heads

Grind & tap heads for 7/16" stud & PRW Stainless Steel rocker arms

MPG port plates

Pushrods & guides

Valve springs & seats

Double roller timing chain

Oil pump

 

Items I still need to evaluate/research:

-Currently have a Mallory dual point distributor, considering doing the Unilite conversion kit

-I have an Edlebrock Scorpion intake or the stock 4V CJ manifold to choose from initially

-Holley 750 CFM double pumper, needs to be rebuilt

-Headers/exhaust

-C6 transmission with OE stall to be rebuilt this winter/spring

-Unkown rear end gearing; Anybody know the best way to assess what I have installed?

 

I expect to have the engine completed early in the new year. Thanks for any feedback/suggestions.

 

Take the money that the "port plates" cost and put it towards an increased capacity oil pan instead. The Scorpion intake is an unusual piece. Some testing I've read about, by Dan Jones, suggests it works well at least above 4000, but it is almost 2 inches taller than a torquer intake and hood clearance may be a problem. The Edelbrock RPM air gap may be an alternative. If the C6 came from a 351CJ, the stall should be okay. The cam sounds ok but, if you are springing for the studs and guide plates I'd be looking for at least .050 more lift, not more duration, to more effectively use the 4V heads. For gear ratio determination try this method. http://www.differentials.com/technical-help/faqs#What%20gear%20ratio%20do%20I%20have?

Have you researched oiling modifications?

 

Chuck

 

Thanks for the response chuck.

 

I have an increased capacity oil plan, but what other oil mods are you referring to? A high flow pump? Are you suggesting the port plates are ineffective?

 

I wondered about that intake. My dad had a custom raised mail slot hood on the car when he drove it so I'm guessing the Scorpion probably won't clear the OE hood with air cleaner. I will probably try out the stock manifold for a bit.

 

As for the cam, I asked my engine builder for something with a moderate idle that would give a decent bump in performance over stock but remains reliable and trouble free and that is the cam he recommended based on that criteria.

 

Unfortunately, the driveshaft and transmission are currently out of the car so I cannot use the method in that link to check my gear ratio. I would assume that it's been upgraded based on how my dad had the car built back in the early 80s. He was running 11.5:1 compression and said he was able to roast 50 series tires without much effort.

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Well I got in the Christmas spirit and finally pulled the trigger on the engine work.;)

 

This is what the build will consist of:

 

New main, cam, & rod bearings

Flat tappet cam - Duration: 280/290 - 214/224 @.050; Lift: .510/.510; Centerlines: 107/117; LSA: 112

.030 cylinder overbore

Ken Block pistons & rings

Hydraulic lifters

DOAE 4V closed chamber heads

Grind & tap heads for 7/16" stud & PRW Stainless Steel rocker arms

MPG port plates

Pushrods & guides

Valve springs & seats

Double roller timing chain

Oil pump

 

Items I still need to evaluate/research:

-Currently have a Mallory dual point distributor, considering doing the Unilite conversion kit

-I have an Edlebrock Scorpion intake or the stock 4V CJ manifold to choose from initially

-Holley 750 CFM double pumper, needs to be rebuilt

-Headers/exhaust

-C6 transmission with OE stall to be rebuilt this winter/spring

-Unkown rear end gearing; Anybody know the best way to assess what I have installed?

 

I expect to have the engine completed early in the new year. Thanks for any feedback/suggestions.

 

Take the money that the "port plates" cost and put it towards an increased capacity oil pan instead. The Scorpion intake is an unusual piece. Some testing I've read about, by Dan Jones, suggests it works well at least above 4000, but it is almost 2 inches taller than a torquer intake and hood clearance may be a problem. The Edelbrock RPM air gap may be an alternative. If the C6 came from a 351CJ, the stall should be okay. The cam sounds ok but, if you are springing for the studs and guide plates I'd be looking for at least .050 more lift, not more duration, to more effectively use the 4V heads. For gear ratio determination try this method. http://www.differentials.com/technical-help/faqs#What%20gear%20ratio%20do%20I%20have?

Have you researched oiling modifications?

 

Chuck

 

Thanks for the response chuck.

 

I have an increased capacity oil plan, but what other oil mods are you referring to? A high flow pump? Are you suggesting the port plates are ineffective?

 

I wondered about that intake. My dad had a custom raised mail slot hood on the car when he drove it so I'm guessing the Scorpion probably won't clear the OE hood with air cleaner. I will probably try out the stock manifold for a bit.

 

As for the cam, I asked my engine builder for something with a moderate idle that would give a decent bump in performance over stock but remains reliable and trouble free and that is the cam he recommended based on that criteria.

 

Unfortunately, the driveshaft and transmission are currently out of the car so I cannot use the method in that link to check my gear ratio. I would assume that it's been upgraded based on how my dad had the car built back in the early 80s. He was running 11.5:1 compression and said he was able to roast 50 series tires without much effort.

 

The most effective oiling mod is what MeZapU is doing, lifter bushings. Other mods such as restricting the oil to the cam bearings, external front to rear oil line, and restricted pushrods can also be used. it is mostly about controlling where the oil goes. Look in the lifter bores, you will see an enormous hole feeding each lifter. 16 places where internal oil leaks occur especially if the lifter bores are a bit worn. The original lifter for a 351C had a specific design to limit the amount of oil sent to the to the top end via the pushrod. To my knowledge, none of the after market lifters have this provision. The result of all this is too much oil in the top end, internal oil leaks, and not enough oil to the crank and rods. Having said all that, there are many 351Cs on the street without any of these mods. As long as it is used conservatively, they may never experience any problems. If the engine is going to be "beat on" a lot the mods are a very good idea. George Pence link. http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/172102126

 

I saw two back to back dyno pulls years ago with and without intake port plates. No difference at all. Granted one is not a real sample size but I think it is a good indicator.Some have reported minor gains using the new style exhaust tongues.

 

If you use the D0AE-L intake a one inch open spacer seems to help output and should not cause a clearance problem.

 

If the diff is still in the car, make the yoke and count yoke revolutions, same as the drive shaft. Good luck with the build. Chuck

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  • 3 weeks later...

Ok, so I'm supposed to be picking up the completed engine this week and have been researching carburetors. Based on the Holley "list" number found on the carburetor that my dad put on the car in the early 80s when he built it up, it is a 700 CFM double pumper with mechanical secondaries. The link below looks exactly like my carb. so I assume Holley hasn't changed the design much in the past 30 years. ;)

 

https://www.holley.com/products/fuel_systems/carburetors/double_pumper/classic_double_pumper/parts/0-4778C

 

My options going forward are, in order of cost from lowest to highest:

 

1. Rebuild it myself - $50

2. Have it rebuilt professionally - $200 (Engine shop quote)

3. Buy new - $400+ (It sounds like ideally I would want vacuum secondaries for my application and something in the 650-750 CFM range for my mild build and expectations)

 

I'm torn because it seems like the carb I have is a good unit, and didn't get much use so if rebuilt properly could be a great performer. However, it is a mechanical secondary so that may be a bit more hassle. Also, I am fairly confident that I will be using the Scorpion intake. Thanks for the feedback guys.

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Rebuild it yourself. There is not much to doing it. The Quick Fuel kit is the best value. If it has the old style gaskets, removing them will be the hardest part of the job. Record the size of the jets, power valves, discharge nozzles, and the number of the accelerator pump cams. It will be useful if you need to calibrate the carb later. Set mixture screws to 1 1/4 ccw from fully seated and accelerator pump levers and floats per Holley specs. Assuming your dad put a decent gear in when he built the car, the mechanical secondaries will not be a problem. Chuck

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Rebuild it yourself. There is not much to doing it. The Quick Fuel kit is the best value. If it has the old style gaskets, removing them will be the hardest part of the job. Record the size of the jets, power valves, discharge nozzles, and the number of the accelerator pump cams. It will be useful if you need to calibrate the carb later. Set mixture screws to 1 1/4 ccw from fully seated and accelerator pump levers and floats per Holley specs. Assuming your dad put a decent gear in when he built the car, the mechanical secondaries will not be a problem. Chuck

 

So you wouldn't have any issue running a 30+ year old carb on a freshly rebuilt engine? And just to be clear, is this the type of rebuild kit you are recommending?

 

http://www.summitracing.com/parts/hly-37-485/applications

 

For my knowledge, what would you consider a "decent" gear? I still haven't jacked the car up yet and measured. I may have time to do it this weekend.

 

I just picked up the engine from the shop this weekend, so now I am eager to get it completed to put back in the car and fire it up. Do I even have the option of sticking with the stock M code intake with this carb? The mounting holes line up, but the mounting flanges are not the same profile. I was hoping to only have to buy EITHER a new car OR an intake, but if the Edlebrock Scorpion intake is too tall, I may not have a choice.

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Rebuild it yourself. There is not much to doing it. The Quick Fuel kit is the best value. If it has the old style gaskets, removing them will be the hardest part of the job. Record the size of the jets, power valves, discharge nozzles, and the number of the accelerator pump cams. It will be useful if you need to calibrate the carb later. Set mixture screws to 1 1/4 ccw from fully seated and accelerator pump levers and floats per Holley specs. Assuming your dad put a decent gear in when he built the car, the mechanical secondaries will not be a problem. Chuck

 

So you wouldn't have any issue running a 30+ year old carb on a freshly rebuilt engine? And just to be clear, is this the type of rebuild kit you are recommending?

 

http://www.summitracing.com/parts/hly-37-485/applications

 

For my knowledge, what would you consider a "decent" gear? I still haven't jacked the car up yet and measured. I may have time to do it this weekend.

 

I just picked up the engine from the shop this weekend, so now I am eager to get it completed to put back in the car and fire it up. Do I even have the option of sticking with the stock M code intake with this carb? The mounting holes line up, but the mounting flanges are not the same profile. I was hoping to only have to buy EITHER a new car OR an intake, but if the Edlebrock Scorpion intake is too tall, I may not have a choice.

The kit you posted should work. If the throttle shaft bores are not worn, there isn't much else that can wear out. If you need to use the stock D0AE-L intake it will work with the Holley. Use a die grinder with a carbide burr bit to open the primary bores in the intake to the same size as the secondary bores. Use a thick insulating gasket between the carb and the manifold to reduce fuel percolation. You may have room to use a 1/2-1 inch open spacer under the carb to help with power at the upper RPM range. Chuck

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  • 2 weeks later...

Hello,

I do not know if you are still working on the engine or have it finished. The D2AE-CA as some have said is the casting number for all 4 bolt main blocks and some 2 bolt. The two blocks are identical the provisions are there for adding the outer bolts to make the two bolt a four bolt. You have to find a set of 4 bolt caps or buy steel ones and have a shop open up the recess for the caps and drill and tap the other holes. It will need align bored and honed. It looks like the date code is 1973, Nov. 27 so that would be right for your car.

On the cracked head a good welding shop can weld up a crack that is on the outside of the head or in the chamber and it can be made as good as new. They have to do proper preheat use the correct rods and also do post weld heat. I have seen NASCAR engine blocks that had the main bearing webs brazed in that ran 500 mile races after being fixed. Drag racers drop valves and stick them in the combustion chamber and they fix them also. It depends on how valuable the head is or how easy you can find another one.

Since you are in Grand Rapids the best welding shop for castings is located in Michigan, MPD Welding. They repair the crashed stamping dies that make the sheet metal for autos. I think they are in Detroit or Grand Rapids one or the other been there a couple times many years ago.

Let us know more about your build.

David

When a man is in the woods and talks and no women are there is he still wrong??:P

David

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The kit you posted should work. If the throttle shaft bores are not worn, there isn't much else that can wear out. If you need to use the stock D0AE-L intake it will work with the Holley. Use a die grinder with a carbide burr bit to open the primary bores in the intake to the same size as the secondary bores. Use a thick insulating gasket between the carb and the manifold to reduce fuel percolation. You may have room to use a 1/2-1 inch open spacer under the carb to help with power at the upper RPM range. Chuck

 

Thanks Chuck. However, if I were interested in going with a vacuum secondary newer carb, would there be anything different you would recommend than posted above?

 

Hello,

I do not know if you are still working on the engine or have it finished. The D2AE-CA as some have said is the casting number for all 4 bolt main blocks and some 2 bolt. The two blocks are identical the provisions are there for adding the outer bolts to make the two bolt a four bolt. You have to find a set of 4 bolt caps or buy steel ones and have a shop open up the recess for the caps and drill and tap the other holes. It will need align bored and honed. It looks like the date code is 1973, Nov. 27 so that would be right for your car.

On the cracked head a good welding shop can weld up a crack that is on the outside of the head or in the chamber and it can be made as good as new. They have to do proper preheat use the correct rods and also do post weld heat. I have seen NASCAR engine blocks that had the main bearing webs brazed in that ran 500 mile races after being fixed. Drag racers drop valves and stick them in the combustion chamber and they fix them also. It depends on how valuable the head is or how easy you can find another one.

Since you are in Grand Rapids the best welding shop for castings is located in Michigan, MPD Welding. They repair the crashed stamping dies that make the sheet metal for autos. I think they are in Detroit or Grand Rapids one or the other been there a couple times many years ago.

Let us know more about your build.

David

 

Thanks David. I was able to find a replacement set of CC heads for a good price, though you give me hope that I may be able to sell the cracked one I still have. My engine is almost complete, and I expect to have some pics up soon, and fire it up this spring.

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I think this is the best vacuum secondary carb available for a street car. http://www.summitracing.com/parts/sum-m08750vs/overview/

Very adjustable using readily available Holley parts and has annular discharge venturi boosters. It is also a real bargain at less than $300.00. Just an opinion. Chuck

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