-8.6CC dish, with AFR225s good mix?
06-12-2006, 08:07 PM
#1
TECH Regular
Thread Starter
Join Date: Aug 2005
Posts: 455
Likes: 0
Received 0 Likes
on
0 Posts
-8.6CC dish, with AFR225s good mix? I was looking at a 370 shortblock with -8.6 CC dished pistons. Planning on running AFR 225 (large chamber?) heads with this combo with GM MLS gaskets. The tech said the compression would be at 8.9 to 1 with that combo. Can anyone confirm that?
This will be run with a D1SC LS6 intake and full exaust. How far could i push it on pump gas with that compression? Id like to get around or over 700 RWHP, hopefully i can do this on 93 octane pump gas? Or would i have to run a higher octane to see its full potential. Im a newbie to FI so any help is appreciated!
This will be run with a D1SC LS6 intake and full exaust. How far could i push it on pump gas with that compression? Id like to get around or over 700 RWHP, hopefully i can do this on 93 octane pump gas? Or would i have to run a higher octane to see its full potential. Im a newbie to FI so any help is appreciated!
06-12-2006, 08:21 PM
#2
On the calculator is use, I came up with roughly 8.8:1. You should be able to push it towards 12lbs easily on pump gas. More with Meth injection. Your HP goals will be in the tune. There are plently of similar combos on here you can read up on that have made great power on pump gas.
06-12-2006, 09:56 PM
#3
TECH Regular
Thread Starter
Join Date: Aug 2005
Posts: 455
Likes: 0
Received 0 Likes
on
0 Posts
Seems im reading superchargers like a bit more cmpression then turbos. So im guessing im right in the ballpark of where i want to be with 8.8 or 8.9? Someone please tell me if im on some serious drugs or somethig here, kinda throwing together something quiclkly and wanna get it right the first time around! I want to make big power, drivebaility can be sacrificed for this, itll have a good size cam, and im looking for ovcer 700, but 800 at the wheels would make me a very happy person. 
I wanna see how much i can get out of this D1SC! This is a dragstrip car first and foremost, and will see a little street time when im feeling silly. Now ive driven cars with huge stalls that ran 110 octane and had almost no vaccum for brakes on the street and i considered that streetable, so im a lil more on the extreme side withw hat i consider drivable. Again i want to make big power and get the lowest ETs possible. Low ETs are my #1 goal in this, everything else is second. Got some of the hardest competition in the country right arond me and i wanna make a good showing!
Also im on my buddies name, i cant get logged onto my account from his house for some reason, in case anyone wonder who the new guy with all the Qs is! Im usually on here as :big bad blackss"
I wanna see how much i can get out of this D1SC! This is a dragstrip car first and foremost, and will see a little street time when im feeling silly. Now ive driven cars with huge stalls that ran 110 octane and had almost no vaccum for brakes on the street and i considered that streetable, so im a lil more on the extreme side withw hat i consider drivable. Again i want to make big power and get the lowest ETs possible. Low ETs are my #1 goal in this, everything else is second. Got some of the hardest competition in the country right arond me and i wanna make a good showing!Also im on my buddies name, i cant get logged onto my account from his house for some reason, in case anyone wonder who the new guy with all the Qs is! Im usually on here as :big bad blackss"
06-13-2006, 03:40 PM
#4
I'm getting 9.46:1 comp ratio.
That is using the following specs:
Iron 370, 4.030 bore, 3.622 stroke, 4.155 gasket bore, .040 compressed gasket thickness, 72cc chamber heads, and 0.00 deck height.
Most LS1's the piston sticks out of the hole some which would make it a little more, about 9.54:1.
If you want 8.8-8.9:1 comp ratio I think you want more like -15 or -16cc pistons w/72cc heads. Hope this helps.
That is using the following specs:
Iron 370, 4.030 bore, 3.622 stroke, 4.155 gasket bore, .040 compressed gasket thickness, 72cc chamber heads, and 0.00 deck height.
Most LS1's the piston sticks out of the hole some which would make it a little more, about 9.54:1.
If you want 8.8-8.9:1 comp ratio I think you want more like -15 or -16cc pistons w/72cc heads. Hope this helps.
06-13-2006, 04:01 PM
#6
LS1Tech Co-Founder
iTrader: (34)
Well, if it were me, and I wanted to push 93 pump gas (oh wait, that is my plan too!), I would stick around 8.5:1. Reason being, you are always going to be pushing that block.
That being said, a veteran FI builder made a few good points to me a while back. He said that one way to look at things is to assume that 15psi (or one bar) will double your engine hp. So if you make say 375rwhp n/a, then 15psi would double that...750rwhp. So it's not a bad rule of thumb to keep that in mind.
I think that 600-650rwhp can be had on 93 pump gas assuming some intercooling or methanol injection or (whatever). 700-750rwhp is where most folks will have to increase octane to reducte detonation. So somewhere in there you will have to tune carefully.
I'm thinking you might need a 15cc dish piston or thereabouts, but you should research that.
That being said, a veteran FI builder made a few good points to me a while back. He said that one way to look at things is to assume that 15psi (or one bar) will double your engine hp. So if you make say 375rwhp n/a, then 15psi would double that...750rwhp. So it's not a bad rule of thumb to keep that in mind.
I think that 600-650rwhp can be had on 93 pump gas assuming some intercooling or methanol injection or (whatever). 700-750rwhp is where most folks will have to increase octane to reducte detonation. So somewhere in there you will have to tune carefully.
I'm thinking you might need a 15cc dish piston or thereabouts, but you should research that.
06-13-2006, 07:23 PM
#7
Humm, the guy told me when i was ordering with the AFR heads and the MLS gaskets id be around 8.9 to 1? I gotta call back and confirm this now. Sounds like i gotta talk to someone else over at this shop thats a lil more familiar with what ill need to do to get to my goals. Im honestly not too sure, and getting mixed results with the research im doing.
Trending Topics
06-13-2006, 07:51 PM
#8
stock 6.0L MLS gaskets are .071. Not .040. That makes diffrence in the compression ratio.
4.03 bore
3.622 stroke
-8.6 dish
0 deck
.071 gasket
72cc chambers
8.94:1 compression.
4.03 bore
3.622 stroke
-8.6 dish
0 deck
.071 gasket
72cc chambers
8.94:1 compression.
06-13-2006, 07:58 PM
#9
Im glad someone knows all the #s to plug into the formula, i wasnt sure on all of them.
So now that we know what i told the shop to build me, should i get on my red phone and call in a stop the presses call, i dont think the parts were ordered yet its about a 6 week lead time on the motor right now.
I think the D1 should be able to handle 8.9 to 1, 370 cubes and healthy heads and cam. Assuming the rest of supporting mods are in place would this be capable of 700+ RWHP? Thats really the lowest i wanna get out of this. Id preffer something closer to 800, if i have to step up to a lil 100 octane or something to accomplish the #s thats cool, but id preffer to be able to do it on pump. Dont get me wrong i dont wanta dyno queen, but i want something that will run with the best of em. Again the #1 goal here is lowest possible ETs first and foremost.
So now that we know what i told the shop to build me, should i get on my red phone and call in a stop the presses call, i dont think the parts were ordered yet its about a 6 week lead time on the motor right now.
I think the D1 should be able to handle 8.9 to 1, 370 cubes and healthy heads and cam. Assuming the rest of supporting mods are in place would this be capable of 700+ RWHP? Thats really the lowest i wanna get out of this. Id preffer something closer to 800, if i have to step up to a lil 100 octane or something to accomplish the #s thats cool, but id preffer to be able to do it on pump. Dont get me wrong i dont wanta dyno queen, but i want something that will run with the best of em. Again the #1 goal here is lowest possible ETs first and foremost.
06-14-2006, 12:43 AM
#10
How high could i bump the compression up with a headgasket change. Seems if anything the centrifigal chargers likw up to 9.5 possibly. If i could get from just under 9 to around 9.5 with a gasket swap i think id be happy with where i was. Im guessing i can also get some work done in the chamber to maybe help unshroud the valves and lower compression a lil more if necessary? Seems im right at a happy medium and can go a lil either way with this as the final combo comes together.
06-14-2006, 01:26 PM
#11
LS1Tech Co-Founder
iTrader: (34)
I think a 8.5:1 370cc, with AFR 225's, good cam, D1, and good intercooler can hit 700rwhp no problem on 93 pump gas. I think 800rwhp will be tricky.
I'm in the same boat right now, I'd have to hit about 800rwhp to comfortable hit my pump gas ET goal. For that reason, I will be going with AllPro heads and a 237/231 cam. My guess is that I won't hit 800rwhp safely on 93 pump with only my 348ci. I'll try it for now, but I'm not discounting the idea of building a 370-400ci 8:1 motor over the winter.
I'm in the same boat right now, I'd have to hit about 800rwhp to comfortable hit my pump gas ET goal. For that reason, I will be going with AllPro heads and a 237/231 cam. My guess is that I won't hit 800rwhp safely on 93 pump with only my 348ci. I'll try it for now, but I'm not discounting the idea of building a 370-400ci 8:1 motor over the winter.
06-14-2006, 01:29 PM
#12
Banned
iTrader: (3)
Join Date: Jan 2006
Location: Texas
Posts: 649
Likes: 0
Received 0 Likes
on
0 Posts
What lenght rod is everyone using for their 370" boost motor?
im not sure which way to go on the rod lenght...I dont know if it should be zero deck or if it shouldbe down in the bore some....
im not sure which way to go on the rod lenght...I dont know if it should be zero deck or if it shouldbe down in the bore some....
06-14-2006, 01:36 PM
#14
Banned
iTrader: (3)
Join Date: Jan 2006
Location: Texas
Posts: 649
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by wickedred
6.125 rods are the norm.
I ask because I see this warning on the manufactures page...
Wiseco Pistons - Chevy
LS-1/LS-2/6.0
Included: Pistons, Pins & Spirolox (no rings)
Note: LS-1 block has 9.240 deck, 6.0 truck block has 9.230. Pick rod length accordingly.
06-18-2006, 12:32 AM
#15
TECH Fanatic
iTrader: (1)
Join Date: Oct 2002
Location: Elmhurst, IL (Chicago Suburb)
Posts: 1,851
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by BIG BAD BLACKSS
How high could i bump the compression up with a headgasket change. Seems if anything the centrifigal chargers likw up to 9.5 possibly. If i could get from just under 9 to around 9.5 with a gasket swap i think id be happy with where i was. Im guessing i can also get some work done in the chamber to maybe help unshroud the valves and lower compression a lil more if necessary? Seems im right at a happy medium and can go a lil either way with this as the final combo comes together.
I agree, my research show that cent.superchargers love 9:5 to 1 compression and on a good forged motor with a proper tune that is the way to go to make BIG power between 12 to 15 lbs of boost. LME is building me a forged 347 LS6 motor as we speak and it will be running the new Dart 225s heads, 9:5 to 1 compression, and with my D1SC blower pushing 14 lbs i should be well at least at 725rwhp, espeically with my new ECS blower cam!
