73 340 rebuild ??

[randy73]

After seeing what Challenger340 said in another thread, I decided to change directions.

the 73 is externally balanced and mine has a 95' 46rh behind it with 3:23 SG and on top is a Weiand dual plane intake w/eddy 750 carb.

So I was thinking I will rebuild the engine and find a set of pistons to raise the compression to 9.1 - 9.5 to 1 with 65cc RPM heads.

Where I live there are not any builders who know mopars, so what pistons would work best to up the compression or should I use stock pistons and shave a little off the deck?

not looking for 500hp or even 400hp, 320-350hp will work just fine for me.

BTW: searched the internet and could not find much on 340's with what I want to do.

[Challenger340]

So you are looking for the "basics" on a 340 rebuild ?

* KB243KTM Piston & Ring Kit will work fine.
Make sure after Boring, that the final Block Honing is done WITH a Torque Plate, and your Machinist understands Hypereutectic Piston fit requirements.
Make sure if YOU are Assembling it, that YOU understand the top Ring End Gap requirements, and file them to Fit.
* A .010" cut off the Block equal & square should do nicely, and get you to 10:1, which is PERFECT for the Eddy Aluminum Heads.
* Re-Size the Rods using ARP brand 180,000 psi Bolts
* Get the Rotating Assembly Balanced

Your Carb & Intake suck... but will work just fine with even a very small Hydraulic Flat Tappet Cam(mid 220'ish @ .050 duration), that will still deliver approx. 350HP level with around 375 ft/lbs Torque even with factory Exhaust Manifolds.

I don't know what you are using for Exhaust ? Headers ? Manifolds ? so I can't make any specific Cam suggestions, but pretty much anything in the mid 220's @ .050 duration Intake pattern can get you there if that's all you want.

Good Luck on your project.

[randy73]

curious as to why you say the carb and intake suck?

I have the same setup on my 70 383 Cuda and it rocks.

I dropped a 440 into a Duster back in 81, had Bo Laws( Chevy shop) help me and took it to the Gators National, got belittled by all the old mopar guys, ended up missing getting into the quarters by 2/10th's and the best part was the guy who put me down the most, lost to me.

Challanger340, not trying to say you are that way, but w/electronic ignition the car runs sounds good, but I have not had it on the road since the mods were done and I want to set it up right. I know weiand is not the best intake but they are not that bad.

[randy73]

So you are looking for the "basics" on a 340 rebuild ?

* KB243KTM Piston & Ring Kit will work fine.
Make sure after Boring, that the final Block Honing is done WITH a Torque Plate, and your Machinist understands Hypereutectic Piston fit requirements.
Make sure if YOU are Assembling it, that YOU understand the top Ring End Gap requirements, and file them to Fit.
* A .010" cut off the Block equal & square should do nicely, and get you to 10:1, which is PERFECT for the Eddy Aluminum Heads.
* Re-Size the Rods using ARP brand 180,000 psi Bolts
* Get the Rotating Assembly Balanced

Your Carb & Intake suck... but will work just fine with even a very small Hydraulic Flat Tappet Cam(mid 220'ish @ .050 duration), that will still deliver approx. 350HP level with around 375 ft/lbs Torque even with factory Exhaust Manifolds.

I don't know what you are using for Exhaust ? Headers ? Manifolds ? so I can't make any specific Cam suggestions, but pretty much anything in the mid 220's @ .050 duration Intake pattern can get you there if that's all you want.

Good Luck on your project.

when you mean get the rotating assembly balanced, do you mean internal or external?
I would like to do full roller, meaning cam, lifters and rockers. When I look at a cam app, it show 268/ 274 112lsa as the best for my heads and stock pistons, it went nuts with the setup I showed above.  so, would like a custom cam w/ 224/ 268 @ .050 sound good, because crane has that cam w/roller lifters?

[Challenger340]

curious as to why you say the carb and intake suck?

I have the same setup on my 70 383 Cuda and it rocks.

I dropped a 440 into a Duster back in 81, had Bo Laws( Chevy shop) help me and took it to the Gators National, got belittled by all the old mopar guys, ended up missing getting into the quarters by 2/10th's and the best part was the guy who put me down the most, lost to me.

Challanger340, not trying to say you are that way, but w/electronic ignition the car runs sounds good, but I have not had it on the road since the mods were done and I want to set it up right. I know weiand is not the best intake but they are not that bad.

How do you Jet your Carb ?
How many different Carb & Intakes have you tried, specifically, on that Engine to compare against ?
No matter,
If YOU like it... that is all that matters, fill ur boots !

[Challenger340]

So you are looking for the "basics" on a 340 rebuild ?

* KB243KTM Piston & Ring Kit will work fine.
Make sure after Boring, that the final Block Honing is done WITH a Torque Plate, and your Machinist understands Hypereutectic Piston fit requirements.
Make sure if YOU are Assembling it, that YOU understand the top Ring End Gap requirements, and file them to Fit.
* A .010" cut off the Block equal & square should do nicely, and get you to 10:1, which is PERFECT for the Eddy Aluminum Heads.
* Re-Size the Rods using ARP brand 180,000 psi Bolts
* Get the Rotating Assembly Balanced

Your Carb & Intake suck... but will work just fine with even a very small Hydraulic Flat Tappet Cam(mid 220'ish @ .050 duration), that will still deliver approx. 350HP level with around 375 ft/lbs Torque even with factory Exhaust Manifolds.

I don't know what you are using for Exhaust ? Headers ? Manifolds ? so I can't make any specific Cam suggestions, but pretty much anything in the mid 220's @ .050 duration Intake pattern can get you there if that's all you want.

Good Luck on your project.

when you mean get the rotating assembly balanced, do you mean internal or external?
I would like to do full roller, meaning cam, lifters and rockers. When I look at a cam app, it show 268/ 274 112lsa as the best for my heads and stock pistons, it went nuts with the setup I showed above.  so, would like a custom cam w/ 224/ 268 @ .050 sound good, because crane has that cam w/roller lifters?

No need for all the expense to move the '73 Cast Crank to Internal Balance. Such an endeavor would involve adding heavy metal to counterweights... too expensive.
Maintaining the "external" Balance is fine for your intended rpm range,
however,
The Factory Crankshaft "External" Balance..... is NOT adequate for the new KB Pistons.

When I say "get it balanced", what I mean is this;
Weigh all the Pistons/Pins/Locks and equalize
Weigh all the Connecting Rod Big Ends and equalize
Weigh all the Connecting Rod Total Weights, then equalize
Weigh the Rings and Rod Bearings
Determine a Bobweight Calculation including Oil factor.

GET THE CRANK BALANCED/CORRECTED to the new Bobweight WITH The Externally Balanced Harmonic Balancer & Flywheel/Flexplate installed.
Your Engine will vibrate if you use the KB Pistons without re-balancing.

You will have many problems installing a ROLLER Cam in a sb mopar... they are NOT drop-in !!! The term ROLLER Cam used by itself, without "Hydraulic" before the Roller.... refers to a MECHANICAL LIFTER Camshaft, that makes far more power... the REAL Roller Cams.
IF,
You are referring to a HYDRAULIC Roller, commonly called an HR Cam & Lifters as discussed earlier, they are called HR Cams to prevent confusion/wrong Parts/Spring rates/ etc., etc.

[randy73]

According to Crane and several articles I have read, Crane retro roller lifters w/crane hyd. roller cams are a drop in fit, see article in link below.

http://www.moparmusclemagazine.com/techarticles/engine/mopp_0001_how_to_install_a_hyraulic_roller_cam/

[Cooter]

According to Crane and several articles I have read, Crane retro roller lifters w/crane hyd. roller cams are a drop in fit, see article in link below.

http://www.moparmusclemagazine.com/techarticles/engine/mopp_0001_how_to_install_a_hyraulic_roller_cam/

Go for it as long as your willing to be our 'ginnie' pig here.

[randy73]

I am going to do it and I hope that I do not end up on a spit.

[randy73]

So you are looking for the "basics" on a 340 rebuild ?

* KB243KTM Piston & Ring Kit will work fine.
Make sure after Boring, that the final Block Honing is done WITH a Torque Plate, and your Machinist understands Hypereutectic Piston fit requirements.
Make sure if YOU are Assembling it, that YOU understand the top Ring End Gap requirements, and file them to Fit.
* A .010" cut off the Block equal & square should do nicely, and get you to 10:1, which is PERFECT for the Eddy Aluminum Heads.
* Re-Size the Rods using ARP brand 180,000 psi Bolts
* Get the Rotating Assembly Balanced

Your Carb & Intake suck... but will work just fine with even a very small Hydraulic Flat Tappet Cam(mid 220'ish @ .050 duration), that will still deliver approx. 350HP level with around 375 ft/lbs Torque even with factory Exhaust Manifolds.

I don't know what you are using for Exhaust ? Headers ? Manifolds ? so I can't make any specific Cam suggestions, but pretty much anything in the mid 220's @ .050 duration Intake pattern can get you there if that's all you want.

Good Luck on your project.

BTW: thanks for the help and I will NOT be assembling this engine, I am looking for a good mopar builder now. With the quality of work I have found in Birmingham, I am looking elsewhere and does anybody know a good builder in Atlanta or Orlando, fl?

I go to these cities frequently.