Advice sought on torque converter please

[Justasgood]

The crane catalog recommends a 3200+ converter, 11.5 - 13:1 compression ratio, and 4000-4800 cruise rpm for that grind number.

Yeah, way too much for what I’m wanting.

 

[Justasgood]

I’m so confused. So the cam that you listed is not purchased or in the car. Correct?

Do you want a TC recommendation for the cam you don’t have but you posted?, Or for the cam that you don’t know what it is?

If it’s the latter, we cannot make any sensible recommendation. Furthermore, W/o cam specs, we cannot truly understand if your problem is a cam size issue verses some other issue.

See my latest post showing the cam in the 505

 

[Justasgood]

Again I apologize, I am trying to get off the prescribe Gabepetin. My mind is racing like I’m on speed and I tend to be all over the map.

In a nutshell:

The 505 has a very agressive cam that at a minimum would require a 3500 Stall converter. Comprehension in the motor while not confirmed is at least 11:1.

I have an automatic transmission with a 3:23 rear gear.

I want a nice sounding cam that will work in this engine using a 2000 stall convey with either the 3:23 or I can reinstall the 3:73. Would prefer to keep the gear as is but open to suggestions

Thanks all for your patience.

 

[BSB67]

The first cam you posted would work fine.

 

[451Mopar]

It sounds like you have many issues going on, with the engine, tuning, converter and such.
What heads, pistons, quench, compression does the engine have. Asking because too small a cam can built too much cylinder pressure for pump gas.
On your carb, I'm guessing the throttle blades are too far open at idle and into the transition circuit resulting on the idle adjustment screws having little effect?
I had a Holley 750 Ultra Avenger on my mild 505 (17cc dish pistons, Stealth heads, about 10.3:1 compression, 0.040" quench, with Comp Hydraulic roller cam XE 236/242 @ 0.050") engine before going to EFI. I had to drill the throttle blades for extra air when closing the throttle blades back down out of the transition circuit. The Avenger is more a street/emission carb, so the idle restrictors also needed to be enlarged for my application. This engine has manual transmission, so no converter info.
On converters part of the decision will come down to how much your willing to spend. On the low end (like $200) a factory rebuilt High Stall converter might stall at 2,800 behind a 505" engine, but the internals are only stock strength. On the higher end (like $1,200+) you can get a custom built converter to your specs. Most of the lower cost off-the-shelf high-stall converters will be loose below the stall speed, but higher end converters can be built to be tight below the stall speed.

 

[Justasgood]

It sounds like you have many issues going on, with the engine, tuning, converter and such.
What heads, pistons, quench, compression does the engine have. Asking because too small a cam can built too much cylinder pressure for pump gas.
On your carb, I'm guessing the throttle blades are too far open at idle and into the transition circuit resulting on the idle adjustment screws having little effect?
I had a Holley 750 Ultra Avenger on my mild 505 (17cc dish pistons, Stealth heads, about 10.3:1 compression, 0.040" quench, with Comp Hydraulic roller cam XE 236/242 @ 0.050") engine before going to EFI. I had to drill the throttle blades for extra air when closing the throttle blades back down out of the transition circuit. The Avenger is more a street/emission carb, so the idle restrictors also needed to be enlarged for my application. This engine has manual transmission, so no converter info.
On converters part of the decision will come down to how much your willing to spend. On the low end (like $200) a factory rebuilt High Stall converter might stall at 2,800 behind a 505" engine, but the internals are only stock strength. On the higher end (like $1,200+) you can get a custom built converter to your specs. Most of the lower cost off-the-shelf high-stall converters will be loose below the stall speed, but higher end converters can be built to be tight below the stall speed.

Thank you for your reply. I wish I had all the specs to address your questions but this engine was built by Big2 engine builders in Gulfport, MS and they are no longer in business as their founder has died. The cam I posted is what is currently in the engine and speaks to why the engine would just die when put in gear as the transmission has a stock converter in it.

I do not wish to match a converter to the as is build because a 3500+ stall will not allow me to enjoy the car as I wish to. As for spend, that is not really a concern if I can achieve what I am trying to achieve.

I have no problem with a 2000-2500 stall and I am trying now to determine which Cam will work best in that scenario.

I don’t have the capabilities to tear down a fresh build to determine the quench, compression etc. nor do I have the knowledge to even figure these metrics out.

Thanks again and I will see if the boys at the shop(where my car and engine are) can try to figure these numbers out.

Stay……..Tuned

 

[451Mopar]

In the '71 Charger, I have a custom converter from Ultimate Converter: Custom High Performance Torque Converters, Ultimate Converter Concepts
This has a high winding 500" stroker, big heads/cam and such.
They set me up with a tight 9" converter that will brake stall around 5,000 RPM, but on the street just part throttle you would think it is a stock converter (but I do have 4.10:1 gears)
Give them a call, they are the experts.

 

[zyzzyx]

Bottom line is your gear ratio is killing you! You need at least a 3:55 or 3:73. Remember that
when you're cruising you need the engine to be above your stall rpm otherwise you make
heat.

 

[68 Sport Satellite]

for street converter, 11" is the way to go. Call PTC like I said before. They're super nice and they'll help you out.

 

[33 IMP]

I would go with a 3500 converter with your current cam.
With the voodoo, I would try for a 2500, (and maybe expect more stall than that, behind a 505) and put THICK head gaskets in it when you put the cam in. 10+ compression, and short duration cams, don't play together well.
And this is a second for PTC Converters. I believe Kenny, the previous owner, is still working there, and is a Mopar lover. He will do you right.
But tell him which gear you are REALLY gonna run. It will make a difference.

Edit: and zzyzx is right. The more converter you have, the bigger trans cooler you NEED!

 

[33 IMP]

Given a choice, I'd rather have a tight ten inch converter, than a loose 11" ( is that what she said?) At the same stall speed the ten will be a better converter.

 

[1KoolBee]

Call Dynamic Converters, give them your specs. They’ll build you the right converter for what you want to do.

 

[66 Sat]

So the cam you are suggesting has the following info:
Retro-Fit Hydraulic Roller. Great midrange torque and power. Likes 2000 RPM stall converter and works great in towing applications with lower gearing. Largest for inboard/outboard performance marine use. ;Advertised Duration (Int/Exh): 270/278 ;Duration @ .050 (Int/Exh): 219/227 ;Gross Valve Lift (Int/Exh): .515/.530 ;LSA/ICL: 110/116 ;Valve Lash (Int/Exh): Hyd/Hyd ;RPM Range: 1800-5800 ;Includes: Cam Only

This might work ok with your stock converter and 3.23 rear given you have 505 cubes, BUT with "at least" 11:1 compression it may be too small and detonation could be a problem.
Your initial post says you have a "mild" engine but the cam and compression don't seem mild to me.
I would change the cam and lower the compression a bit as suggested, leave the converter and gears alone and see how you go
OR
leave the cam and compression alone and get a high stall converter and throw the 3.73 gears in there.

Your first post suggests the first option will be more suited to what you want though (cruiser, occasional track), whereas the second option is more track, occasional cruiser.

 

[33 IMP]

So the cam you are suggesting has the following info:
Retro-Fit Hydraulic Roller. Great midrange torque and power. Likes 2000 RPM stall converter and works great in towing applications with lower gearing. Largest for inboard/outboard performance marine use. ;Advertised Duration (Int/Exh): 270/278 ;Duration @ .050 (Int/Exh): 219/227 ;Gross Valve Lift (Int/Exh): .515/.530 ;LSA/ICL: 110/116 ;Valve Lash (Int/Exh): Hyd/Hyd ;RPM Range: 1800-5800 ;Includes: Cam Only

This might work ok with your stock converter and 3.23 rear given you have 505 cubes, BUT with "at least" 11:1 compression it may be too small and detonation could be a problem.
Your initial post says you have a "mild" engine but the cam and compression don't seem mild to me.
I would change the cam and lower the compression a bit as suggested, leave the converter and gears alone and see how you go
OR
leave the cam and compression alone and get a high stall converter and throw the 3.73 gears in there.

Your first post suggests the first option will be more suited to what you want though (cruiser, occasional track), whereas the second option is more track, occasional cruiser.

Excellent summation, imo.

 

[Justasgood]

So the cam you are suggesting has the following info:
Retro-Fit Hydraulic Roller. Great midrange torque and power. Likes 2000 RPM stall converter and works great in towing applications with lower gearing. Largest for inboard/outboard performance marine use. ;Advertised Duration (Int/Exh): 270/278 ;Duration @ .050 (Int/Exh): 219/227 ;Gross Valve Lift (Int/Exh): .515/.530 ;LSA/ICL: 110/116 ;Valve Lash (Int/Exh): Hyd/Hyd ;RPM Range: 1800-5800 ;Includes: Cam Only

This might work ok with your stock converter and 3.23 rear given you have 505 cubes, BUT with "at least" 11:1 compression it may be too small and detonation could be a problem.
Your initial post says you have a "mild" engine but the cam and compression don't seem mild to me.
I would change the cam and lower the compression a bit as suggested, leave the converter and gears alone and see how you go
OR
leave the cam and compression alone and get a high stall converter and throw the 3.73 gears in there.

Your first post suggests the first option will be more suited to what you want though (cruiser, occasional track), whereas the second option is more track, occasional cruiser.

Thank you so much for that synopsis. I am going to call the converter guru and the cam company and pair up a team to work with my setup 3:23 gears.

Sounds like less duration, thicker head gasket to bring the compression down and maybe a well built 2000-2500 stall will give my the set up and performance I am seeking.

You guys are the best!!!!

 

[451Mopar]

I have gathered the parts for another 512" stroker. Going the 4.375" bore size as the block bores did not clean up at 0.040" over.
This is being built as a mild street pump gas engine, so I'm using the 27cc dish pistons. The end compression ratio will depend on the cylinder heads I use.
The three choices of heads I have on hand to use are
1. My current choice is my old rebuilt Brodix B1-B/S heads with 1.6:1 rockers which will put my compression around 11:1.
2. Least likely choice, but have the old set of Edelbrock MW heads. Compression around 10.4:1? But would be the most expensive to use as I don't have a rocker arm set for the heads.
3. Second choice is CNC ported 440 source stealth heads. Maybe 9.7:1 compression? Again no good set of rocker arms for this head. I do have some old stainless steel 1.7:1 CAT rocker arms, but I would have to rebuild them with new roller tips and adjusters as the stock parts were junk although the rocker bodies are decent.

Anyhow, just showing that different heads can give a wide range of compression ratios.

 

[33 IMP]

I have gathered the parts for another 512" stroker. Going the 4.375" bore size as the block bores did not clean up at 0.040" over.
This is being built as a mild street pump gas engine, so I'm using the 27cc dish pistons. The end compression ratio will depend on the cylinder heads I use.
The three choices of heads I have on hand to use are
1. My current choice is my old rebuilt Brodix B1-B/S heads with 1.6:1 rockers which will put my compression around 11:1.
2. Least likely choice, but have the old set of Edelbrock MW heads. Compression around 10.4:1? But would be the most expensive to use as I don't have a rocker arm set for the heads.
3. Second choice is CNC ported 440 source stealth heads. Maybe 9.7:1 compression? Again no good set of rocker arms for this head. I do have some old stainless steel 1.7:1 CAT rocker arms, but I would have to rebuild them with new roller tips and adjusters as the stock parts were junk although the rocker bodies are decent.

Anyhow, just showing that different heads can give a wide range of compression ratios.

For a "mild street pump gas engine", I'd use the stealths, or put .120 cometics under the b1/bs. (Maybe .090s . Whatever it takes to get it to low 10 cr)

 

[Justasgood]

For a "mild street pump gas engine", I'd use the stealths, or put .120 cometics under the b1/bs. (Maybe .090s . Whatever it takes to get it to low 10 cr)

I can’t comprehend what you are saying. The guild as a whole won’t change. Head gasket thickness was suggested to lower the Compression but I have no idea what you are suggesting.

Please forgive my 1) ignorance of engine building and 2) brain fog from the meds I’m on.

 

[RemCharger]

I can’t comprehend what you are saying. The guild as a whole won’t change. Head gasket thickness was suggested to lower the Compression but I have no idea what you are suggesting.

Please forgive my 1) ignorance of engine building and 2) brain fog from the meds I’m on.

He quoted and replied to 451Mopar

 

[Justasgood]

He quoted and replied to 451Mopar

Sorry, I thought this was in reference to the challenges I’m trying to figure out. I swear this medication is great for my back pain but boy does it mess with my head