i do actually.its all about the wheelspeed,too much shocks the tire and chassis and your out of the race,too little and your chasing.power management is racing now.i dont doubt you got a stroked motor to go down the street from what you had.out of the box thinking would be the only way to setup a fast street combo (destroked or stroked)based upon what i have seen and hear guys talk about on this board.i have driven and been in both and both can make power.
Destroking - Facts or fiction
- Thread starter Jerryl
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This conversation should have its attention directed to the individuals who really want to maximize any given combo. We definitely don't have the different forms of racing putting tons of money into R&D for us anymore. We already have the all of the facts. You probably cant come up with a combo that hasn't been tried or tested. We are only working from 209 to roughly 281 cubic inches. 500 hp is 500hp on a 109 with a 3.4 stroke crank, off center 3.8 with a 3.50 or on center 4.1 with a 3.625. The difference is when and where does my 500 hit the ground in relation to my torque. Lots of ways that you can jockey those figures around. Cam profiles, lots of smart people have tried different ramps, lobe separations, and durations. To me looking at a cam card is like looking at the Matrix, but some people can plot a graph in their head of the performance. I showed my cam card once to a board member and was immediately told that I was going to need some compression. He was right. I had the exact same cam in one motor and changed a few things on the piston design, night and day difference. Weight, Buick has always expressed using heavy cranks, lighten one up a little, knife edge and polish it. I have a Winberg crank in a motor that is so beautiful, I almost didn't want to run it. Whoever initially ordered it had to have about 5K in the crank. Aluminum rods, there have been a couple in some 109 and stage motors that work great if you really want your car to rpm quick stroked or destroked. I believe the last Duttweiler motor was destroked and I don't think that Ingersoll ever had motors larger than 260 cubic inches. 15 years ago you could not give away a set of cast iron stage 2 heads, a crank with less than 3.40 stroke, or and odd fire crank. I was told that you could make more power with the cast irons but at the expense of weight, you will never use that short stroke crank get a 3.625 and with our electronics you can't get an odd fire crank to work. I paid $100 for a 3.750 stroke odd fire crank and traded it for a 3.59 even fire. I would love to have the 3.75 back because an odd fire can work now, odd fires are proven to run very low 7's. Someone went outside the box and made it work. I would have wanted to take this conversation to the advantages of stroking a motor.
There are some assumptions being made in this thread that I'm sure are not being shared by others. When I say street car,I'm not talking about quarter mile times. I'm talking about the attributes that make a street set-up more desirable than a race set-up on the street. If you're running a de-stroked engine on the street and it's outperforming the bigger engines on the street,you are running a race car on the street and it lacks all of the desirable attributes of a big brawny street engine. Hopefully,I haven't misspelled anything as that would be proof that all of my statements are wrong.
I will not lie, I have had blinders on when it came to destroking my engines. Common practice and knowledge has always been to make it bigger in every aspect. On the east coast high compression Busch engines with 3.625 stroke cranks were plentiful and up north ASA had 9 to 1 motors with a multitude of crank strokes. I didnt know short stroke or Indy stuff had existed until I sold and bought some stuff around Colorado and the west coast. I am very open to being involved in this conversation even tho I may get mad about all of the short stroke items that went thru my finger tips. I still have 2 raw BMS forgings that I can turn one down to a 3.0 stroke and play with it in say a 4.020 on center stage 2 or a .030 over 109. I am hoping that additonal comments come flowing in from people that have talked to their engine builders, experiences being on or off the track or just the curiosity of the "what if." Keep the constructive dialog coming.
Pronto
No amount of evidence will ever persuade an idiot.
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Stock stroke, stroked, destroked all can work from what I've seen. Think the thing being lost is the most successful that run each style have worked long and hard to optimize their engine. Whatever their secrets they found, I doubt they would readily give up all the details to others. That leaves a lot of info out for others to guess on.
Jerryl
Tall Unvaccinated Chinese Guy
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I would think that 90% of our cars run a 109 and it makes the most sense to keep the discussion relevant and relatable.
Out of the box is installing an electric motor and batteries and traction control in a TR, or run variable timing with direct injection on methanol. And . . . .as with any paradigm shift, “out of the box” is frowned upon, and I understand why that is on this board. That not a dig towards anyone at all, just a fact in any discipline on any subject. Hell, some still refuse to believe that ported injection is inferior to TB injection, or that a supported aftermarket ECU has little to no value.
I know Billy Bob in Texas says anything bigger is always better but IMO, a stroked 109 with a 3.8” piston is not really worth the expense and hassles.
Out of the box is installing an electric motor and batteries and traction control in a TR, or run variable timing with direct injection on methanol. And . . . .as with any paradigm shift, “out of the box” is frowned upon, and I understand why that is on this board. That not a dig towards anyone at all, just a fact in any discipline on any subject. Hell, some still refuse to believe that ported injection is inferior to TB injection, or that a supported aftermarket ECU has little to no value.
I know Billy Bob in Texas says anything bigger is always better but IMO, a stroked 109 with a 3.8” piston is not really worth the expense and hassles.
yes and everything has to be setup around that type of understanding
well said!
things move around alot on a 109 block,stroked or destroked
Absolutely true. I would add that most have never been to the track or have only been their less than a handful of times.
Mike T
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Fastest 109 out there is a stock stroke and it's well into the 8's. Nothing exotic according to the owner.
Pronto
No amount of evidence will ever persuade an idiot.
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Maybe not "exotic" but things no one will ever know...
Mike T
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In other post he seems very open about most of the build including CR. I believe he said mid 8 CR and all off the shelf parts.
Pronto
No amount of evidence will ever persuade an idiot.
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If it was that easy, everyone would be doing it.
NY Twin Turbo
All the good stuff.....Times 2.
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It’s obvious the whole package, engine, suspension, transmission, front to back is well thought out and thoroughly tuned.
But ultimately the power comes from mass airflow. And I’m going to guess that there’s a bunch of little tricks being used to hold a stock block together.
Mike T
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Did I say it was easy? He has stayed the course and chipped away a little at the time. Stayed with basically stock configuration (stroke/CR) and proved that it's unnecessary to stray from that.
Pronto
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Yes, the 109 block moves all around for sure at 9 second power. I can't imagine how it doesn't twist in half with 8 second power. Even filling the block doesn't stop all the movement.
I truly think that once a person feels that their bottom end is "bullet proof" caps and/or girdle, the green light is on for test and tune. If our blocks would have came with 4 bolt mains from the factory, oh boy. I am glad that we have the capability to add a flat girdle to strengthen our bottom ends. With the addition of forged cranks it really did allow us to turn up the wick with a little less fear. I'll mention the RJC head clamps as well. I have only seen 1 109 that was split down the middle, we dont have problems like the old Fox body 5.0 blocks that hit the limit around 550 hp.
NY Twin Turbo
All the good stuff.....Times 2.
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NY Twin Turbo
All the good stuff.....Times 2.
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Funny you should mention this. A very close friend of mine who monitors this forum daily recently did exactly this.
After a hard pull, he noticed a sudden drop in oil pressure without audible bottom end knock. He quickly determined the motor needed to come out. After opening the motor up they found no visible damage of any bottom end components. Crank, caps, bearings, all seemed good. Then it was noticed that the cam was stuck and wouldn't slide out of the block. The cam bearings were spun. And when in the process of looking for a moving part failure, he failed to notice the crack right down the middle of the lifter valley. The block had literally split in half!!!!
This was a well built motor, forged crank, steel caps, ARP hardware, and was certainly high nine second capable. He doesn't get to the track often and was not able to wring out the nine before this catastrophe happened. But he is a capable tuner and may have had it tuned to that power level when this happened. There was no other visible indications that it had been detonated.
As of now, our only guess is that he breached the strength threshold of his blocks power tolerance.
