More boost?
11-17-2004, 10:12 PM
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More boost?
Am I crazy to want to run more boost?Think I'm risking hurting the motor?
502, 8.5:1 compression ratio, timing at 30 deg.B&M 250 makes 6 lbs of boost with 3.3" pulley.Running 93 octane fuel.
I got a 3" pulley was gonna try but now I'm starting to rethink it.Spinning that little blower faster I'm sure will make the fuel hotter.Should I pull a couple of degrees of timing out of it and go for it or do you think I'm risking a melt down?
I know a superchiller would be the way to go but I dont have the space( blower drive is right under the bottom of the seat)
Thanks for any advice.
502, 8.5:1 compression ratio, timing at 30 deg.B&M 250 makes 6 lbs of boost with 3.3" pulley.Running 93 octane fuel.
I got a 3" pulley was gonna try but now I'm starting to rethink it.Spinning that little blower faster I'm sure will make the fuel hotter.Should I pull a couple of degrees of timing out of it and go for it or do you think I'm risking a melt down?
I know a superchiller would be the way to go but I dont have the space( blower drive is right under the bottom of the seat)
Thanks for any advice.
11-17-2004, 10:15 PM
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Re: More boost?
Do you feel confident in your ability to read light detonation on the plugs?
Cause depending on your camming, you could be pretty close to the line.
Cause depending on your camming, you could be pretty close to the line.
11-17-2004, 10:43 PM
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Re: More boost?
Cam specs: dur: Int=240 Exh=253, lift: Int .575 Exh .595, lobe sep 113.
While I'm not a super expert on plug reading,they look pretty good to me.What would early signs of det. look like? Light aluminum specks?
By the way I'm running a Nickerson preped dominator.
While I'm not a super expert on plug reading,they look pretty good to me.What would early signs of det. look like? Light aluminum specks?
By the way I'm running a Nickerson preped dominator.
11-17-2004, 11:01 PM
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Re: More boost?
I would think your at the edge myself...I don't think your blower has any more effective squeeze left in it...just more heat.
I would hate to see you pushing it for a 1-2mph gain.
Can you tell us more...
You have a single or dual carb setup?
What heads? Iron/Alum. with what valves
Exhaust?
Cam? Roller, blower grind.
What rpm you spining the motor at? whats the lower pulleys diameter to figure out the overdriven ratio.
Just for comparision...We run 8.03:1 aluminum headed 557ci motors at 6psi using 10-71s with 30deg timing, no stats and chilly Lake Michigan water...thats my limit for safety.
I would hate to see you pushing it for a 1-2mph gain.
Can you tell us more...
You have a single or dual carb setup?
What heads? Iron/Alum. with what valves
Exhaust?
Cam? Roller, blower grind.
What rpm you spining the motor at? whats the lower pulleys diameter to figure out the overdriven ratio.
Just for comparision...We run 8.03:1 aluminum headed 557ci motors at 6psi using 10-71s with 30deg timing, no stats and chilly Lake Michigan water...thats my limit for safety.
11-18-2004, 07:17 AM
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Re: More boost?
Back4more,
Heads are stock iron rectangle port with inconel exh valves.
Cam is a hydraulic flat tappet.
Running gil exhaust.
WOT=5200rpm
Not to change the subjet of this post but any recommendation on what to do for more power without turning the blower faster; Upgrade to hydraulic roller cam?If so what grind is recommended.Or set up to alumunim heads?Any opinons on the Edelbrock marine heads?
Thanks
Heads are stock iron rectangle port with inconel exh valves.
Cam is a hydraulic flat tappet.
Running gil exhaust.
WOT=5200rpm
Not to change the subjet of this post but any recommendation on what to do for more power without turning the blower faster; Upgrade to hydraulic roller cam?If so what grind is recommended.Or set up to alumunim heads?Any opinons on the Edelbrock marine heads?
Thanks
11-18-2004, 08:33 AM
#8
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Re: More boost?
a roller with the same duration specs will give you as much as 10% more area "under the curve" (that's good). It's cause they open and close so fast.
You got more room for improvement, though, in head selection. You can let somebody port the bejeebies out of yout GM squares OR you can buy some killer heads. Then re-pulley to bump your boost back to where it was (it will drop with improvements in the motor's ability to flow air) and you're cookin.
Your little blower can still give you some more usable volume, but NOT at boost levels higher than where you are now.
You got more room for improvement, though, in head selection. You can let somebody port the bejeebies out of yout GM squares OR you can buy some killer heads. Then re-pulley to bump your boost back to where it was (it will drop with improvements in the motor's ability to flow air) and you're cookin.
Your little blower can still give you some more usable volume, but NOT at boost levels higher than where you are now.
