Yellow Bullet Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
342 Posts
Discussion Starter #1
As in terms of static comp ratio, timing, and boost. This is with two bullseye S475's w/1.32 on a conventional headed BBC in a drag boat that will run very cool water temps. This is a 555cid aluminum engine and flashes straight to 73-7500rpms and stays there for the duration of the pass, maybe 7-8 sec at the most.
Considering doing away with the intercooler, engine is 9.3-1 static and presently running 23psi
But dont want a melt down. Thanks in advance, Hass
 

·
Registered
Joined
·
3,714 Posts
I can tell you that I run C-16 on a 565 F3-139 non-intercooled and 40 psi boost with 9/1 CR static. But it took some pistons and a pile of rings to get the tune up there. But it can be done.

Blessings..........Ron
 

·
Registered
Joined
·
342 Posts
Discussion Starter #3
I can tell you that I run C-16 on a 565 F3-139 non-intercooled and 40 psi boost with 9/1 CR static. But it took some pistons and a pile of rings to get the tune up there. But it can be done.

Blessings..........Ron
Thanks Ron. In other words, it can be done but it makes the tuning window very narrow.
I'm sure that before I could get any kind of recommendations for timing and a/f that i would need to measure my IATs.
 

·
Registered
Joined
·
3,714 Posts
Thanks Ron. In other words, it can be done but it makes the tuning window very narrow.
I'm sure that before I could get any kind of recommendations for timing and a/f that i would need to measure my IATs.
When I started on this journey I was burning up pistons and rings like crazy. At times I would have two different ring types on each side of engine for testing. I finally put it on VP Import (ultimate blower gas) and got the tune up going and then weened it over to C-16. If I could afford the Import I would still be using it. But it takes your first born to buy a drum.

Good luck...........................Blessings..............Ron
 

·
Registered
Joined
·
2,014 Posts
I personally ran my 565 BBC with an F2 at 9to1 with 30PSI and 30 degrees of timing and never had a problem. Now you should have lower air temps than a Procharger so you will be fine with what you are doing. I wouldn't be worried at all with C16.
 

·
Registered
Joined
·
870 Posts
I have always wondered about this as well. I have a YSi combo where I run a A2A and spray it meth injec as well.

My IAT temps are in the 120 range as I cross the strip.

Combo makes 22-23 psi-but I bet I'm losing at least 2 psi through the cooler.

I've always wondered what would happen if I pull the cooler and run C16 like the renegade guys. IAT temps would probably double.
 

·
Registered
Joined
·
342 Posts
Discussion Starter #7
I personally ran my 565 BBC with an F2 at 9to1 with 30PSI and 30 degrees of timing and never had a problem. Now you should have lower air temps than a Procharger so you will be fine with what you are doing. I wouldn't be worried at all with C16.
Thanks Pooch, that is what I was wanting to hear. I currently run 23psi of boost and 32* of timing. When i pull the cooler I will back it down to 30* and see what the plugs look like. Thanks again, Hass
 

·
Registered
Joined
·
342 Posts
Discussion Starter #8
One last question, what a/f ratio to shoot for when starting out with this? low 11's?
 

·
Registered
Joined
·
3,714 Posts
One last question, what a/f ratio to shoot for when starting out with this? low 11's?
That would be a good place to start.

Blessings.........Ron
 

·
Registered
Joined
·
342 Posts
Discussion Starter #10
That would be a good place to start.

Blessings.........Ron
Thanks Ron, I'm going to give it a try. I will make sure that the tune in the carb is dead nuts on before I remove the intercooler as i'm sure its going to gain a couple pounds of boost without the cooler. Will also take a couple degrees of timing out at first and see what it looks like.
 

·
Registered
Joined
·
342 Posts
Discussion Starter #11
Well I have decided to keep the cooler for now as I have been helping a friend build a very simular engine and he is going nonintercooled. I decided to let him be the guinea pig, lol.
His deal is 605cid, Brodix BB2 heads, custom turbo cam from bullet, twin S475 borgs w/1.32 turbin housings. C&S carb on C-16.
First outing he kept turning it up more & more till he was at 32degrees of timing and 35psi and took out a piston and a head gasket. Sounds like to much timing to me. I think he should settle in on about 30psi & 28degrees. Its not my deal and I could only make suggestions, it was his setup to ultimately make decisions on & tune. But looks like he found out what wont work.
He has it repaired and will be giving it another shot this coming spring.
 

·
Registered
Joined
·
3,714 Posts
With the 40 psi tuneup I trim the timing back to the 26-28 area with a 18 degree Big Chief head. You really need a retard capability, at the lower boost area (below 23 psi area) it like's a lot more timing (33-34), then needs to pull back above that rapidly.

That would be my suggestion.

Blessings.........Ron
 

·
Registered
Joined
·
342 Posts
Discussion Starter #13
With the 40 psi tuneup I trim the timing back to the 26-28 area with a 18 degree Big Chief head. You really need a retard capability, at the lower boost area (below 23 psi area) it like's a lot more timing (33-34), then needs to pull back above that rapidly.

That would be my suggestion.

Blessings.........Ron
Thanks Ron, a friend and I built a boost operated mechanical retard for my mag and it works perfectly and is fully adjustable.
My bud likes the msd stuff, I told him at this level he should be looking at an msd 8 or 10 if he insists on staying electronic. Maybe with a 7531.
 

·
Registered
Joined
·
8,464 Posts
i run mine at 35lbs and 27* timing and a box stock probe piston. blow thru carb. didnt hurt a single engine part all season. 65 runs
 

·
Registered
Joined
·
547 Posts
I personally ran my 565 BBC with an F2 at 9to1 with 30PSI and 30 degrees of timing and never had a problem. Now you should have lower air temps than a Procharger so you will be fine with what you are doing. I wouldn't be worried at all with C16.
Jason, Would you be willing to share some details on this combo? I have a non-intercooled 540 with an F-2 and it would be nice to compare so I know how far I can go. Or PM me if you would like. Thanks
 

·
Registered
Joined
·
342 Posts
Discussion Starter #16
Thinking about giving it a try without the cooler. I will buy a stand alone knock sensor, make a pass with the cooler on the engine and adjust the knock sensor till the light is just barely turned off, then pull the cooler off and see if it shows any knock. Will probably back the boost down and sneak it back up while keeping an eye on the sensor.
 

·
Registered
Joined
·
1,821 Posts
Thinking about giving it a try without the cooler. I will buy a stand alone knock sensor, make a pass with the cooler on the engine and adjust the knock sensor till the light is just barely turned off, then pull the cooler off and see if it shows any knock. Will probably back the boost down and sneak it back up while keeping an eye on the sensor.
What stand alone do you plan on using? I'm interested as well.
 

·
Registered
Joined
·
38 Posts
Hi Guys, I know this thread is old but wanted to run a question about my setup across you. I run an iron headed (Hi Ports) 347, blow thru, with an F2. and water to air IC with comp around 9.2 with c16. I've been running it at 30* and pulling timing with the 7531 and 3bar map to that at 28-29psi im at 19-20* timing. The plugs were always fat and the car just never sounded "clean". I'm told that I should run c14 instead of 16 because im not making enough heat to really burn it off. Reading through this thread it seems i've been pulling too much timing. I've only gotten wide bands on it since last outing so wasn't able to check AFR's before. So my question is, should i switch fuels or just try bumping up the timing a bit?

Thanks
 
1 - 20 of 20 Posts
Top