[Stan Weiss]

Steve,

Cars with automatic transmissions with high stall torque convertors do not follow this. But sticks and automatic transmissions with low stall torque convertors do. The final answer is always track testing. What this graph show is rear wheel torque in each gear and the engine RPM mapped by MPH. In theory you want to shift at the RPM where the rear wheel torque in the gear you are in crosses the rear wheel torque of the gear that you are shifting into.

Stan

[ponjohn]

Originally Posted by dci

Thanks for sharing this. I have been telling my clients this for years, but they are still apprehensive. I have one client that has close to 100,000 miles on his rods now. I built that engine for him back in the 80's and he use's it for a daily driver in the summer months highway and in town. It's a 455 too not a 400.

Al. rods?

Something to consider.

[Dragncar]

Originally Posted by ponjohn

Al. rods?

Something to consider.

The whole aluminum rod thing in street Pontiacs goes back 80s. There were almost no available steel rods for Pontiacs. Crower discontinued their Pontiac forging. There were SD455 rods, custom steel billets and BME aluminum.
We all seen them for sale in HOs catalog.
When I did the 455 I am still running in the mid/late 80s I bought NOS 455 rods. 100$ each. Military grade shot peening and resize and those were 1200$ rods.
Changed to generic H beam years ago because I was worried about snapping them under the pin.
Eagle offering Pontiac rods (and the E head) changed everything. There is just no real need to run a aluminum rod in a street Pontiac anymore. Sure, you can do it with success and all. But I would rather not worry about things. Running on cold days, the warm ups, cycles ect.
Engines do not make any more power with aluminum rods vs steel, dont ET any better with just a rod change either. Engine might seem "snappy", rev real quick with no load stabbing the gas. But pulling a 3000-4000 lb car there is no difference.
Are the easier on things in high end race engines, sure. It does give a cushion of sorts for the rod bearings if your engine detonates. OK, but tune your engine properly first and run steel rods I say.
There are reasons Pro Stock went back to steel rods.

[Stan Weiss]

Originally Posted by Dragncar

The whole aluminum rod thing in street Pontiacs goes back 80s. There were almost no available steel rods for Pontiacs. Crower discontinued their Pontiac forging. There were SD455 rods, custom steel billets and BME aluminum.
We all seen them for sale in HOs catalog.
When I did the 455 I am still running in the mid/late 80s I bought NOS 455 rods. 100$ each. Military grade shot peening and resize and those were 1200$ rods.
Changed to generic H beam years ago because I was worried about snapping them under the pin.
Eagle offering Pontiac rods (and the E head) changed everything. There is just no real need to run a aluminum rod in a street Pontiac anymore. Sure, you can do it with success and all. But I would rather not worry about things. Running on cold days, the warm ups, cycles ect.
Engines do not make any more power with aluminum rods vs steel, dont ET any better with just a rod change either. Engine might seem "snappy", rev real quick with no load stabbing the gas. But pulling a 3000-4000 lb car there is no difference.
Are the easier on things in high end race engines, sure. It does give a cushion of sorts for the rod bearings if your engine detonates. OK, but tune your engine properly first and run steel rods I say.
There are reasons Pro Stock went back to steel rods.

So what are they?

Stan

[67'7F6'Bird]

More Racing Videos.

https://www.dropbox.com/s/i03kd0ayd3...10.51.mp4?dl=0

[67'7F6'Bird]

4th Racing Video.

https://www.dropbox.com/home/RAV?pre...6+14.27.15.mp4

[67'7F6'Bird]

The DCI 475 CI Ram Air V is Running Great We will be back at the track in about two weeks. I will be working on Improving my Launch and increasing the Shift RPM. We anticipate MPH to Increase. If anyone is in MA or NH and has some 26 X 8.5 or 26 X 9 Slicks that I can borrow let me know.

[dci]

Steve, It's going to run fast once you see what it likes. Keep us posted !!!

[67'7F6'Bird]

Originally Posted by dci

Steve, It's going to run fast once you see what it likes. Keep us posted !!!

Hi Don,

My Brother and I have and have had many high performance Pontiac engines including Ram Air IV's, HO455's all with Solid Roller Cams, High Compression and heavily Ported, with that said this DCI 475 CI Ram Air V pulls harder than all of them. Considering we are low compression, 8.5 to 1 running 87 Octane fuel we are very happy with the initial results. This Firebird has been on many hour long drives with no issues. The ET and MPH will definitely Improve. Just Improving my 60' and Shifting higher we will see the car in the mid to low elevens. I know the car can 60" in the 1.6 Range and with the Additional upper RPM power the results may be better than anticipated.

I will always post real time results as always.

Thank You Don J, for all your Support especially after the sale.

[dci]

Thank you Steve for the Kudos !!!! It is amazing how hard these heads pull in the upper rpm's. We are seeing way better MPH on the backside of the quarter than any other heads we have used previously. I think you will see that as well when you start upping the shift points. Can't wait for your next outing !!!

[ponjohn]

Originally Posted by dci

Thank you Steve for the Kudos !!!! It is amazing how hard these heads pull in the upper rpm's. We are seeing way better MPH on the backside of the quarter than any other heads we have used previously. I think you will see that as well when you start upping the shift points. Can't wait for your next outing !!!

Don is that a function of port velocity?

[67'7F6'Bird]

My Firebird started Smoking, I hope its ok.

https://www.youtube.com/watch?v=_fY_...ature=youtu.be

[Jack Gifford]

[Dragncar]

Originally Posted by Stan Weiss

So what are they?

Stan

Make more power, truth. We all know at the Pro Stock level just a couple HP cost big, big money. If they can even get a tiny bit more with a simple rod change it gets done.
Dont believe me, ask Tom Molnar. Knows more about steel rods than just about any human alive.

[Dragncar]

Originally Posted by 67'7F6'Bird

My Firebird started Smoking, I hope its ok.

https://www.youtube.com/watch?v=_fY_...ature=youtu.be

I noticed it smoking in one of the vids. Hope is all OK, something simple.

[67'7F6'Bird]

Originally Posted by Dragncar

I noticed it smoking in one of the vids. Hope is all OK, something simple.

That video the Oil Dipstick was not in all the way, Everything is all good.

[Stan Weiss]

Originally Posted by Dragncar

Make more power, truth. We all know at the Pro Stock level just a couple HP cost big, big money. If they can even get a tiny bit more with a simple rod change it gets done.
Dont believe me, ask Tom Molnar. Knows more about steel rods than just about any human alive.

Dragncar,
I was looking to see if you had any technical information as to why.

One thing that I was told by what has been a pretty reliable source in the past is that they are able to run less piston to head clearance now (because of the steel rod).

Stan

[Dragncar]

Well sure they are going to be able to run less piston to head clearance with steel rods vs aluminum. Tom mentioned aluminum rods get "compressed" a tiny bit. That is why they have been known to be easier on bearings ect. Especially if your engine is not in top tune.
But he was referring to the energy it takes to compress the aluminum rod. They act like shock absorbers. But that energy it takes to compress the aluminum rod is energy that could be used to accelerate the crankshaft.
Takes tens of thousands of dollars per HP at that level. Even a tiny bit helps.
Tom says keep your engine in tune and the rod bearings still come out perfect in steel rod engines.
Top Fuel the forces are so violent and there is such a excess of power the shock absorber quality is the most important thing.

[dci]

Originally Posted by ponjohn

Don is that a function of port velocity?

Actually John I think it's from the port volume shape and discharge coefficient. This of course creates air speed, but turbulent air speed is not good. My port is pretty stable at higher air speeds and I contribute that to the higher rpm push.

[dci]

Originally Posted by Stan Weiss

Dragncar,
I was looking to see if you had any technical information as to why.

One thing that I was told by what has been a pretty reliable source in the past is that they are able to run less piston to head clearance now (because of the steel rod).

Stan

I can see an argument for both sides of the connecting rod choice. I don't think that a Pro Stock engine really needs a cushion or shock absorb-er, but it definitely can benefit from a tighter quench area. I can see an aluminum rod reducing reciprocating weight though and that can be an influencing factor for the rpm range they run at.