Speed Demon and Holley

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Postby Sirshredalot » Tue Apr 01, 2008 12:14 am

Hey Nick....sorry I missed your post.

You can run an 8.5:1 engine on E85.....but it will be most advantageous to have a higer CR....Somthing like 11.5-13:1.

Nice thing is that you can run a wider LSA like 112-114 to build more cylinder pressure with a "smaller" cam and still reap the benefits.
If youre looking mainly at AutoX....what RPM's do they usually run?

I take it that five speed has a deep first gear coupled with a performance oriented rear gear like 3.23-3.73's.
With regards to cams....I think youll like the cam you have...its small enough to get you good cylinder pressures and vacuum signal...should be pretty responsive with the cubes.

SWT racing is right....For the money you can spend, a holley can/will perform just as well as a BG/QFT/Proform carb.
I ALWAYS use the nylon bowl screw washers...Theyre gold compared to those piece of crap paper leak-a-ma-jigs.
Also...I always spray my gaskets with white lithium before I install them so that they seal well and dont tear when you remove them.

My personal recommendation would be a 600 holley DP with stainless high flow needle and seats....center hung floats....High flow metering blocks and gasoline style jets. Alcohol jets would be very large and probably flow more fuel than you could use. The stainless needle and seats will take more pressure too before they flood.
The carbs without the airhorn...ya know, the cool looking contoured ones...dont really offer any power advantage over a carb WITH a choke horn until you get into alot of RPM or horsepower.

I know that buick products dont like to rev....I dunno bout Rover's.
I would think that you would want a wider powerband though at more liveable rpms for the street...if you plan to drive it to the tracks.

All in all I think youre sweating the details too much unless its a purpose built race car....13:1 on E85 would be great....but gas is cheaper(sorta), easier, and more available.
You can always convert later....and mill youre heads to get a higher CR and better quench....even angle milled...although youd have to do the intake to match.

Alot of the speed will be in the chassis and the recovery power off of corners....which it doesnt sound like youll have any problems with.

Good luck and keep us updated.
God bless
-Shred
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Postby NixVegaGT » Tue Apr 01, 2008 10:51 am

Thanks for the input Andrew. I do have great access to E85 around here but, as Fred was saying, if I want to compete in Targa/Tarmac rally, I may not have access to it at event locations.

SO then my biggest concern is the standard hypereutectic pistons I have. That was one of the considerations for the E85. It's a lot more stable and I figured that would be fine with these pistons. Then again they may be just fine for 11.5:1… It does take a lot more cash to run E85.

Smart idea bout the lithium grease! I figured as much about the choke horn. I will be redlining at 6500. You are right about the Buicks and high RPM. The biggest limiting factor is the rocker shafts on the head. They need gussets on the ends to keep them stable at high RPM. I'll take a pic and post it. Without them the rocker shafts break off. WOW.

On the T5. I just finished disassembling it this morning! I'm not putting the G-force gears in till I mock up the engine/trans for the motormount locations. The gears in the G-force set are:

2.94, 1.94, 1.34, 1.00 ratios in gears 1 thru 4
I'm using the stock 0.59 for the OD.
My rear gear is 3.42:1

Thanks for the support guys. It's good to avoid building something in a vacuum. You know what… I think your right: E85 is probably just more than I can bite off right now. Hmmmm
- Nic '73 Vega GT "DogBoxx" Batwing LS1
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Postby NixVegaGT » Fri Apr 04, 2008 11:00 am

OK it's official I'm not going with E85 till I convert to MegaSquirt in a few years. Maybe they will be making E85 from switchgrass then.

ON that note. DO you think I should run a more aggressive cam to offset the compression??

This:

http://www.crower.com/misc/cam_spec/cam ... 33&x=0&y=0

VS this?:

http://www.crower.com/misc/cam_spec/cam ... 32&x=0&y=0
- Nic '73 Vega GT "DogBoxx" Batwing LS1
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Postby Sirshredalot » Sat Apr 05, 2008 1:05 pm

Have you already purchased the first cam?

If you already have the cam then Id use it....but if you havent purchased the cam Id look into the bigger one.

It really just depends because I have absolutely no experience with those engine.....The bigger cam is an all around good cam...should make alot of midrange torque depending on how your heads flow.

Itll have great torque and a great top end charge....especially in 300ci.

Id say go bigger....but thats what I always say.

God bless
-Shred
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Postby NixVegaGT » Mon Apr 07, 2008 9:11 am

Thanks, Bro. I think I may do that. I have already purchased the cam but I want it to be the right choice. I can probably get most of my money back for the cam I have since it's new.

The more I look at it the more I like it.

Thanks for the input, Shred.
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