Advice sought on torque converter please

[68 Sport Satellite]

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

Some have good luck with Dynamic but I first went with them before going to PTC and Dynamic specd out the wrong converter for my car and it drove terrible. I later spoke with one of the owners and he gave me full refund and admitted it was the wrong converter size and stall for what I asked for. Because of this I had to pull and install converters twice. PTC for the win. I’m sure Dynamic makes a great product, but the first agent who helped me didn’t spec mine out correctly based on my car or needs and I gave him everything in detail.

 

[Justasgood]

Little update: contacted PTC and they were great. I gave them all of what I know of the build and more importantly the cam specs. I explained my goal for the motor and car.

He made me feel very good about leaving it as is and they are building a tight 2500-2800 I think he said 9” or 9 1/2” converter that should behave well at lower rpm cruising.

So now I wait for a week and I’ll put it together

Also spoke to an experienced engine builder and he also feels the cam characteristics will be manageable with said converter and set up.

So fingers crossed and stay tuned.

Thanks again to the group here. The knowledge and willingness to help and share continues to astound me.

Kurt

 

[68 Sport Satellite]

can't wait to hear the results!
so they spec'd this converter for your currently installed Crane cam that has RPM operating range of 3500-7000?

 

[Justasgood]

can't wait to hear the results!
so they spec'd this converter for your currently installed Crane cam that has RPM operating range of 3500-7000?

The discussion about that and the build in general were basically advertised versus realized specs. The true 505 versus advertised for 440RB I’m told changes this slightly. Bottom line is, I have what I have. Trying to get a true compression number as well. I have another 440 bought from a member here that I have accumulated all that I need except Pistons. If the 505 doesn’t work with this converter, I pull it and sell it.

 

[68 Sport Satellite]

The discussion about that and the build in general were basically advertised versus realized specs. The true 505 versus advertised for 440RB I’m told changes this slightly. Bottom line is, I have what I have. Trying to get a true compression number as well. I have another 440 bought from a member here that I have accumulated all that I need except Pistons. If the 505 doesn’t work with this converter, I pull it and sell it.

oh, sorry, what I meant to say is - did PTC spec out the new 2500 rpm stall converter for your existing cam? If so, should it still work even though the advertised cam rpm range starts at 3500 rpm?

 

[Justasgood]

oh, sorry, what I meant to say is - did PTC spec out the new 2500 rpm stall converter for your existing cam? If so, should it still work even though the advertised cam rpm range starts at 3500 rpm?

Yes. They spec’s for the crane cam the engine was built with. They also stated that a cam for a 440 will be milder in the 505. Don’t ask me to explain but the engine builder I spoke with went into great detail regarding the cam specs, torque converter, true compression, static compression etal

 

[451Mopar]

Little update: contacted PTC and they were great. I gave them all of what I know of the build and more importantly the cam specs. I explained my goal for the motor and car.

He made me feel very good about leaving it as is and they are building a tight 2500-2800 I think he said 9” or 9 1/2” converter that should behave well at lower rpm cruising.

So now I wait for a week and I’ll put it together

Also spoke to an experienced engine builder and he also feels the cam characteristics will be manageable with said converter and set up.

So fingers crossed and stay tuned.

Thanks again to the group here. The knowledge and willingness to help and share continues to astound me.

Kurt

Sounds good. Good torque converters are worth the money. What I noticed about my "tight" 9" converter is at light throttle there does not seem to be much slip, even at highway speeds. Under wide open throttle, it stalls near 5,000 RPM (heavy car 4,150 lbs, and maybe around 500 uncorrected/actual rear wheel HP.) The only thing I noticed is at the drag strip, the tight converter does not hit as hard off the line like a looser high stall converter. Not an issue for me as I don't go to the track very often, and the suspension is not setup for drag racing anyhow.
In the Wallace calculator, with 120 MPH Quarter mile @ 4,150 pounds, shows 552 HP. 11.5 ET @ 4150 shows 539 HP? The MPH/ET were at Bandimere mile high altitude.
ET-MPH-HP Calculator

 

[RemCharger]

Love them Wallace calculators. GIGO

 

[RemCharger]

https://www.chevelles.com/threads/how-much-does-elevation-effect-horsepower.703529/

 

[Justasgood]

Love them Wallace calculators. GIGO

Am I missing something? What does this mean?

Sorry again for the revelation of my engine building ignorance

 

[RemCharger]

They are missing alot of variables.

 

[Justasgood]

Okay so we started tearing the engine down. Shame on me for trying to go the quick easy route. Took the driver’s side head off to measure bore and determine how high in the hole we were at TDC. This engine had been sitting since built for a few years. The owner would turn it over by hand once a week while it sat in his shop.

So far, we’ve determined the bore to be 4.360 and the piston stamping confirms. These are Ross domed pistons part #99782. Upon inspecting the heads and valves, we noticed hole 5(driver side 1,3,5,7) had a cracked exhaust valve. We haven’t removed the other head yet as it doesn’t matter at this point. I am gutted and discouraged.

So now I’ll seek out some Flat top pistons with the same profile(specs), do a light cylinder hone, and reassemble.

Guess cruising days are over for a long while as I am awaiting back surgery.

Pics for comments and / or advice.

Thanks again Fam, I appreciate all the group offers.

And now NSFMopar lovers


As it is and a page from Ross showing specs of current pistons.

And what I am looking at as a replacement set:

Hope every has a safe and wonderful Labor Day weekend,

Kurt

 

[BSB67]

Intake valve.

Remove the valve and inspect it. Looks more like a scratch than a crack in the pic.

What’s wrong with the pistons?

 

[Justasgood]

Intake valve.

Remove the valve and inspect it. Looks more like a scratch than a crack in the pic.

What’s wrong with the pistons?

If you blow up the Picture you can see the defect.



These are the pics my mechanic sent so I have not seen them in person.

As for the pistons, I am trying tp get the compression down to a manageable compression. Not sure what the compression is as of now. as you can see, the piston at TDC is pretty much all the way to the top of the cylinder the head gasket is .051.. Not sure a head gasket change will get me to 11:1 or lower but then again, I know nothing of this. I would love to be able to use as built but I am not sure it will be what I need it to be.

If I had to guess (and it's just a guess) I would say the compression is at least 12:1

 

[451Mopar]

Good thing you found the cracked valve before it damaged the engine.
Prayers for your back surgery, hope all goes well.