505 Dyno Results

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wildbill

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I just wanted to post my 505 Dyno results as a point of reference for anybody planning a build. I only ran it on the dyno because I have been fighting a rear main seal leak and wanted to verify that it was fixed (it finally is - after many attempts!).

440 block (1973) - 0.030 over. 440 source rotating assembly. 10.6:1 calculated compression. Howard's solid flat tappet cam 720152-08.
https://www.summitracing.com/parts/hrs-720152-08/make/chrysler
EDM lifters. Smith Brothers custom pushrods (ended up at 9.8 inch effective length). Mancini racing aluminum rockers.

Trick flow 240 heads. Trick flow intake manifold.

High volume oil pump.

Dyno pulls with shop's carburetor (I didn't even ask what CFM as I run Sniper EFI in the car). Large dyno headers. Cheap HEI distributor with whatever advance springs it came with (I run Hyperspark in the car). 36 degrees total timing. Water temperature was about 150 degrees. Nice cold air.

I'm very happy with the results. I actually run this in a 73 D100 long bed. Best ET is 11.52 at about 117mph. I run 91 octane pump gas. Track elevation here is 2700 feet. I haven't weighed the truck but guessing around 4500 pounds?

PXL_20241217_013330871.jpg
 
I just wanted to post my 505 Dyno results as a point of reference for anybody planning a build. I only ran it on the dyno because I have been fighting a rear main seal leak and wanted to verify that it was fixed (it finally is - after many attempts!).

440 block (1973) - 0.030 over. 440 source rotating assembly. 10.6:1 calculated compression. Howard's solid flat tappet cam 720152-08.
CHRYSLER Howards Cams 720152-08 Howards Cams Mechanical Flat Tappet Camshafts | Summit Racing
EDM lifters. Smith Brothers custom pushrods (ended up at 9.8 inch effective length). Mancini racing aluminum rockers.

Trick flow 240 heads. Trick flow intake manifold.

High volume oil pump.

Dyno pulls with shop's carburetor (I didn't even ask what CFM as I run Sniper EFI in the car). Large dyno headers. Cheap HEI distributor with whatever advance springs it came with (I run Hyperspark in the car). 36 degrees total timing. Water temperature was about 150 degrees. Nice cold air.

I'm very happy with the results. I actually run this in a 73 D100 long bed. Best ET is 11.52 at about 117mph. I run 91 octane pump gas. Track elevation here is 2700 feet. I haven't weighed the truck but guessing around 4500 pounds?

View attachment 1716340618
Nice! What was your fix for the rear seal leak?
 
I tried everything including multiple rope seals with no success. The machine shop that built my short block failed 3 times. I failed at least 5 times.

I took it to a more race oriented shop in town. They were able to use a regular lip seal carefully lined up correctly. They didn't give me any exact details on which way it had to be moved.

No drips after a bunch of idle time, running under load, and two dyno pulls. So I'm hoping we have it figured out!
 
I forgot - using a stock seal retainer. Two aftermarket ones made things way worse. Fastfish one piece seal also failed.

Has been a year and a half ordeal.
 
I forgot - using a stock seal retainer. Two aftermarket ones made things way worse. Fastfish one piece seal also failed.

Has been a year and a half ordeal.
Wow! I have a new seal coming and certainly want my drip, drip to stop after fixing it. What I've seen may be a key is to sand the bottom of the retainer to remove some material to allow the seal to be closer to the crank. Since the engine is in the car this job should be fun!
 
I hope you get it figured out. Mine was a nightmare. I've pulled the engine out at least 6 or 7 times. Even in a truck doing it in the vehicle was pretty hard. I have an aftermarket oil pan so I had to jack the engine up to get it out. Just a headache inducing job.
 
I hope you get it figured out. Mine was a nightmare. I've pulled the engine out at least 6 or 7 times. Even in a truck doing it in the vehicle was pretty hard. I have an aftermarket oil pan so I had to jack the engine up to get it out. Just a headache inducing job.
Ugh, I can only imagine. With no lift available it will be a "dad on his back on the concrete floor" job. Hey, if working on our cars was easy (and cheap!) everyone would be doing it!
 
What’s the difference between the two different colored curves?

Do you have a sheet with the actual data on it?
 
I just wanted to post my 505 Dyno results as a point of reference for anybody planning a build. I only ran it on the dyno because I have been fighting a rear main seal leak and wanted to verify that it was fixed (it finally is - after many attempts!).

440 block (1973) - 0.030 over. 440 source rotating assembly. 10.6:1 calculated compression. Howard's solid flat tappet cam 720152-08.
CHRYSLER Howards Cams 720152-08 Howards Cams Mechanical Flat Tappet Camshafts | Summit Racing
EDM lifters. Smith Brothers custom pushrods (ended up at 9.8 inch effective length). Mancini racing aluminum rockers.

Trick flow 240 heads. Trick flow intake manifold.

High volume oil pump.

Dyno pulls with shop's carburetor (I didn't even ask what CFM as I run Sniper EFI in the car). Large dyno headers. Cheap HEI distributor with whatever advance springs it came with (I run Hyperspark in the car). 36 degrees total timing. Water temperature was about 150 degrees. Nice cold air.

I'm very happy with the results. I actually run this in a 73 D100 long bed. Best ET is 11.52 at about 117mph. I run 91 octane pump gas. Track elevation here is 2700 feet. I haven't weighed the truck but guessing around 4500 pounds?

View attachment 1716340618
Nice!
 
Thanks for posting

Can you put up the 11.52 time slip too?

Thanks
 
Square up the retainer in a rod cap grinder and take a thou or two off it. Make sure it's square. Now the secret is out.
 
Square up the retainer in a rod cap grinder and take a thou or two off it. Make sure it's square. Now the secret is out.
I would if I had one. Plan to rub the retainer on sandpaper to take a little meat off. One video I watched showed the guy putting a thin film of grease on the crank then bolting down the retainer, then pulling it back off to look at the grease to see the contact. Sounded good to me.
 
That track is altitude factored……there’s another couple of tenths in your truck if you ever got to run closer to sea level.
 
Even without DA info, his data and results seem to line up pretty well, IMO. And that is not always the case.
 
Using the Moroso slider, 117mph is 8.4lbs/hp.

Using the fuel flow and bsfc numbers off the dyno sheet shows the uncorrected hp to be 520.

520hp x 8.4 lbs = 4368

Seems like that’s pretty close.
 
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