200 CFM Research

[larrycavan]

[200cfm]

I went to retest Friday evening and lost a rod in the burn out box at about 5300. Number 1 rod snapped and wipped out the bottom. Ugly!!!! Will be down for the summer as I plan a replacement motor. New intake though looks promising.

[106-1194218389]

Hmmm ..... Friday wasn't nice, my cousin lost a rod in his Camaro first run "Friday Night" - Coincidence or "Twilight Zone" ???

John

[larrycavan]

Sorry to hear that stuff guys


Bad luck must be making it's rounds. You would not believe how many people I've spoken to since the 4th weekend who have had things break.....

I had issues with a Wiseco Piston in a big single myself.

[Otto]

Sorry to hear that was looking forward to see what she was going to do.

[106-1194218389]

Hey 200CFM,
How is your motor coming? Are you having any success? Like Bruce was commenting, I also love to see how you are doing. Anybody can make a Chevy run. But to make a Studebaker takes talent.

John

[200cfm]

I salvaged the heads and crank from the motor. And have started planning on a replacement block. Working on a mock up engine now for a twin turbo design. Designing and fabing around the limited spacing is the biggest problem. And studying the possible intercooling options. Future motor will have Howards racing rods to solve the weak link problem.

Here is a view of the broke rod.








The rod bearing was ok so it wasn't a bearing failure. And the pin still rotated in the piston so that part didn't lock up. I think it was the inertial weight load from the piston that weakened and pulled apart the rod. Motor was hitting close to 6200 on the final top end pulls this season. And I had raced this block for close to 10 years and it had seen a lot of strain.

[bruce]

OUCH!!

[106-1194218389]

Are the Howards rods steel or aluminum? If aluminum make sure you leave extra deck clearance. We used to run Howard's Aluminum rods and they used to stretch a little and we had to run .060" That has been years ago though so I hope technology for them has caught up.

John

[200cfm]

They are steel. The small end is set up for the more available early sbc 2.000" dia. bearing which will offer better bearing selection. Same length at 6.625" and same pin diameter at .8750." Very pricey too but lighter in weight and rated to 1200 hp. Next up will be lighter and stronger custom forged pistons. Thinking of Ross brand. Do you know if high boost engines can go with thinner and low resistance design rings or should it stay with the thicker rings?

[106-1194218389]

Nice looking rods! Most of the Japanese cars run fairly thin rings even with a turbo. I feel you can get away with a thin ring, but I would tend to lean towards a stainless with a chrome face. My cousin is a wrench on a top fuel and believe it or not they are using a moly face ring. I think I would ask the ring manufacturer or even better call Ross if that is the way you are going. I know they will be up on the technology better than me. I still lean towards chrome faced stainless for that application. I have a friend that is building turbo'd Japanese cars for racers and he is actually putting up to 40 lbs boost in those suckers. I will see if I can get a hold of him also.

John

[tweaks]

Seeing those old rods pistons took me back 40 years when I was doing apprenticeship in NZ....I think you got your moneys worth out of them..lol
I would go along with John and discuss with the Piston manufacturer your application ,whats the usage ,chamber shape ect they can then machine correct tolerances and oil control holes into the piston for you.

Lynds

[jsa]

[106-1194218389]

John (JSA) brings up some very good points. Now with a turbo it is impossible to use the exhaust header for vacuum for the vacu-pan system. We have used old smog pumps driven by a belt for a vacuum source. Of course if you want to spend $300 - $500 you can buy a high dollar billet one. That would be a good addition, a vacuum pan system. Also JSA mentioned CP pistons. They are my favorite and they guys are very knowledgeable there. One thing I have heard some of the guys with Turbos are doing is running lower static compression in the 6 to 1 range. Supposedly this gives more room for more air fuel to be packed in thus giving more horsepower. Does anyone know if this is a fact with turbo engine?

[jsa]