Questions, Questions, and More Questions

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Ls7camaro
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Joined: Tue Mar 25, 2008 11:31 am
Location: Medina, OH

Questions, Questions, and More Questions

#1 Post by Ls7camaro » Wed Dec 28, 2016 11:36 am

OK, with all the TV shows/Internet Shows and all the other stuff on the WEB these days, there are questions. So I ask, and get either the cold shoulder.

So. I see guys running turbo setups, and see them at shows spending a ton of cash on an engine, and then the turbo. Why do most people keep the cubic inches around 4 to 500? I see guys list all the parts in the motor, so if you do the math, machine work, and all of that, why keep the cubic inches so small? Why not build say a 632 or 704? Bigger is better right?

Same question but for the blower guys. There is a shop that specializes in throwing a 8-71 or 10-71 on everything. He built his shop car to compete on Dyno Challenges/Race. The car runs on E85 and has clicked off a few high 7 second passes. He built a 505 inch big block and a 10-71 and what looks like an Enderle Alcohol injection tuned for E85. Again, isn't bigger better? that same 10-71 on a by means, huge big block?

Transmissions, I see guys starting to say they are buying TH400s but in 2 speed format.

Why do people put E85 Down? They keep claiming that it will destroy the motor internals? But I see the Blower shop engine that runs it all year.

I also see guys bashing nitrous now. Is that still a viable option to run with E85 on a 12.5 to 1 BBC with Merlin Iron Heads?
I can't wait for race season, this has got to be the year.

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ytnova
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Re: Questions, Questions, and More Questions

#2 Post by ytnova » Thu Dec 29, 2016 12:26 pm

That is a lot questions! First, my thoughts on engine size. I like to look at the engine package as a whole and look for weak spots and where others have had problems. A couple of examples, you can always add cubic inches by increasing the crankshaft stroke, right? This raises some issues, the compression height is now lower, ie. pin closer to the top of the piston. This opens up issues with the rings, you may need oil ring supports, you may not be able to lower the rings on the piston away from the combustion chamber like you want, the top of the piston may now be too thin to deal with high boost. Basically, by increasing the stroke too much, we may have now made a problem under high boost that would not of been a issue with a shorter stroke crank. The same idea applies with the bore size, there is a point where going larger in diameter now makes a weak point, cylinders too close together, to close to the outside of the block, water jacket, etc. There is also the thought that as you increase the bore size, you also are increasing the square inches of exposed cylinder head, giving the cylinder pressure a greater lever to try and lift the cylinder head. The basic thought is build something as large as you can that is VERY durable and just add boost to make up for the loss in cubic inches.

The TH400 deal, pretty simple, a powerglide is physically only able to fit down to certain gear size and the large gear step or rpm drop between 1 and 2 is upsetting the chassis or tire. A th400 case is much larger in diameter to allow a smaller gear step.

E85, I personally love it. It does require some additional maintenance, but not to the extent of methanol. The biggest issues are with storage and the subsequent moisture absorption, it will not hurt anything internal in a engine. The other issue is guys not checking the ethanol content and then adjusting their tune accordingly.

I'll let the blower guys chime in on their stuff.

E85 and nitrous, I just think there are not enough guys doing it, those that have figured it out are not sharing the information. If I was running ALOT of nitrous or a really big tune up, I would still use gasoline.
I am not really sure what the question is, but I am pretty sure the answer is Big Block.

Ls7camaro
Posts: 113
Joined: Tue Mar 25, 2008 11:31 am
Location: Medina, OH

Re: Questions, Questions, and More Questions

#3 Post by Ls7camaro » Fri Dec 30, 2016 11:17 am

thanks for the reply. right now I am working 2 jobs and trying to wrap one car up. I was dealing with a big speed shop and they don't kind of answer questions. Would rather you just pay them. moving on to a smaller shop that seems way better.
I can't wait for race season, this has got to be the year.

mink127
Posts: 4
Joined: Mon May 11, 2020 10:18 am

Re: Questions, Questions, and More Questions

#4 Post by mink127 » Tue May 12, 2020 11:05 am

Ok for the bigger and better stuff you talked about (sorry if i'm late replying, i was scrolling trough and just joined but I would like to chime in). Bigger doesn't always mean better. The bigger you go, yes, you have the potential for more power. But you can use a smaller engine that makes just as much, if not more power then a big block. Making more power in a small block, increases the compression ratio, but makes the engine more prone to preignition and detonation, however this problem can be resolved to a certain point using a higher octane fuel. A lot of it comes down to cost, too. Not everyone has the money to spend on big blocks and more power. Not to mention people would eventually run out of space in their car to fit a larger engine. Yes, increasing size increases power, notably torque when increasing stroke. The other thing you asked about blower size, money of course, but possibly the AFR. It's better to run a more rich mix, so increasing the blower will force more air in, but then you may have stabbed yourself in the back when you don't make as much power because you just made the mix more lean.

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