Can someone double check some final comp numbers

I went from 93 pump gas builds to alcohol type builds so final compression numbers weren't very important to me but I'm almost ready to install my 572 and gotta figure out what race gas I will be needing for this build.

Engine specs
572 cubic inch. 4.500 bore-4.500 stroke
pistons. Nitrous inverted dome -24cc
Cometic head gasket 4.540 bore .060 thick
was told its 15.92cc
B1 head chamber 67.5cc

Using an online calculator I'm getting 107.4cc
11.91 compression.

I love the oxygenated fuel.. like q16 or something along that line. More than likely you may be able to get away with some C12 depends on the budget you have set for your project

VERY low budget but I will run one higher grade than needed because of the planned nitrous hit. LOL.

q16 was the fuel of choice in Ultra for the nitrous car

If you tow the car up and back you will be surprised at how little fuel you actually use. Towing up and back. I use less than a half a gallon per pass.. shakes out to be about $10 a run

I’m a one man show so I will be driving it up and back

http://www.diamondracing.net/tools/

This is the best one I've used. I've done the actual math to check it in the past, and it's completely accurate.

Assuming zero deck and 1cc for area above the rings, I get 11.82.

That's about where i'm at . ( 11.2 or 11.7 I can't remember ) and I run 116

Appreciate the second set of eyes guys. Heck maybe I can run BP93 pump gas with this combo.

I thought 11.9-1 WAS pump gas

Not enough info to calculate CR. Need to know piston to deck.

If its perfectly zero deck, then 11.92 rounded the nearest hundredth.

Spraying helps pump gas.

I ran in hot rods pump gas drags in 06 with a 12.8:1 engine, and sprayed 200 at it on pump gas, in summer heat. I ran it later with pump, and sprayed 350 at it. When I'd drive it around on really hot days and load the motor at low rpm, it would ping.

I checked the filter regularly when racing it on pump, and spray, and never saw any signs of damaging detonation.

Heck that’s the highest compression I’ve had in an engine for over 8 years. Lol. Lots of horsepower left on the table with this engine setting it up for nitrous. These were Jason Dixbys rods and pistons from when he switched over to turbo power.

at zero deck, I get 11.87. at .020 in the hole I get 11.37 on my home brew spreadsheet calculator.

bob

Thanks guys. It’s zero deck.

It probably won't be a very competitive combo but I will get my feet wet with nitrous. Someone said I was scared to go fast so I should be ok going a little slower. LOL.


Untitled by John Cadamore, on Flickr

Untitled by John Cadamore, on Flickr

Untitled by John Cadamore, on Flickr

Is that the CR you were shooting for? If so, golden. If not...bummer.

I honestly didn’t have a target in mind. I had this engine together with a set of Wiseco pistons as a NA combo. I talked to Vic at Wisco and he recommended only hitting them with 200-250. I had bought a set of nitrous pistons from Jason Dixby when he was switching to turbo power so I used those pistons in this build. I have a Sledgehammer plate system that is good for a 300-700 hit

At zero I get 11.77 on Diamond Pistons calculator

What cam is in it ? I ask because a nitrous grind that opens the exh really early, would benefit from more compression. Also how much nitrous are you going to use ? Depending on the cam, it might want 13 or more. You know what your doing with an engine, so you'll learn through testing . Also are the chambers softened on your heads ?

Its a cam Motion cam 833 lift intake 765 ex. 286 in. 304 ex.
114 lobe center in at 110
I.S. lists my Sledgehammer plate at 150-600+
chambers are not softened as I wasn't sure how to do it PROPERLY.
I have another set of B1 heads with smaller chamber and Titanium valves but I have to port them yet so that's a long way off. I don't expect to be a top runner on my budget and will mostly be racing my bracket car. I just wanted to see what I could do but I'm getting old real fast. Heck putting the engine and transmission in by myself wore me out. LOL. the engine plate will be on and off several times yet to get the headers on and find out where I want to weld on the O2 bungs.


Untitled by John Cadamore, on Flickr

Untitled by John Cadamore, on Flickr

Untitled by John Cadamore, on Flickr

Looks really good, best advice I can give you...go real conservative on the timing, and I mean real conservative. If you start at 300hp, I'd be in single digit timing with those heads. Like 9 or 8* if consulting with inductionnsolutions on the timing, make sure you tell them the heads are not softened. Good luck