about a Nitro cackle engine

[Dragsinger]

Could a fellow achieve enough cackle to enjoy with a SBC N/A mechanical injection? I am thinking an engine on a stand/trailer to fire up at the Friday night car show at the local hamburger drive-in. Just for fun and conversation.

SBC because of simplicity and inexpensive parts.

[77cruiser]

Not sure but sounds like a fun project. I saw a NA sbc in a dragster only once but it had cackle & that instant throttle response that nitro has.

[hoodeng]

Just add a little PO.

Cheers.

[hoodeng]

And i forgot to mention,,,it will sound sensational but stand back!

Cheers.

[Dave Koehler]

Could a fellow achieve enough cackle to enjoy with a SBC N/A mechanical injection? I am thinking an engine on a stand/trailer to fire up at the Friday night car show at the local hamburger drive-in. Just for fun and conversation.

SBC because of simplicity and inexpensive parts.

Got Zoomies?

[Circlotron]

Got Zoomies?

Make them same diameter as a full tilt top fuel engine. Don't worry about port matching. The diameter of a tube greatly affects the sound. N/A means no blower belt whine if course.

[Truckedup]

Guys run 98 % nitro in fuel class land speed racing bikes..Most of these are N/A vintage engines..Many use modified carbs that literally just pour in the nitro...Obviously it takes some expertise..They are started on alcohol I believe...They use shorter larger diameter pipes than a gas engine...It does get loud on fuel but they are more interested in going fast than impressing the neighbors...More or less doubles the power ....

[DCal]

You could use a dual-idler gear drive and achieve a whine that matches the RPM, not a blower but pretty cool sounding.

[engineguyBill]

Back in the day there was a racing class called Junior Fuel. Limited to small block engines (can't remember the size limitation, but think it was around 370 cu. in), unblown (most competitors used Hilborn injectors or similar units), just about all cars were very lightweight front-engine dragsters. Of course at the time most of the Top Fuel dragsters were also front-engine configuration. Like Dave said a noisy gear drive camshaft would probably enhance the noise factor.

[ROCCO]

Look for Spud's Nitro Notes
FUELINJECTIONENT.COM

www.fuelinjectionent.com/nitro_new.php

Best source I'v seen for folks who are Nitro-Curious.

[nitro2]

Guys run 98 % nitro in fuel class land speed racing bikes..Most of these are N/A vintage engines..Many use modified carbs that literally just pour in the nitro...Obviously it takes some expertise..They are started on alcohol I believe...They use shorter larger diameter pipes than a gas engine...It does get loud on fuel but they are more interested in going fast than impressing the neighbors...More or less doubles the power ....

If anyone is running 98% nitro and are ONLY doubling the power, then they are WAY out to lunch. 4 times the power is straightforward, 5-6 times the power is a better aim, and that's naturally aspirated.

[Truckedup]

Guys run 98 % nitro in fuel class land speed racing bikes..Most of these are N/A vintage engines..Many use modified carbs that literally just pour in the nitro...Obviously it takes some expertise..They are started on alcohol I believe...They use shorter larger diameter pipes than a gas engine...It does get loud on fuel but they are more interested in going fast than impressing the neighbors...More or less doubles the power ....

If anyone is running 98% nitro and are ONLY doubling the power, then they are WAY out to lunch. 4 times the power is straightforward, 5-6 times the power is a better aim, and that's naturally aspirated.

Nope about 2 to 2.5 times would be the best for vintage OHV bike engines.This is compared to a equal gas engine.. These are Bonneville and El mirage record holders....Triumphs, Harleys that need to run wide open for three miles without exploding and throw you off at 185 mph...

[MadBill]

Seems like we're looking at different parts of the elephant. Perhaps 5x is chemically possible but mechanically for a vintage engine, 2X is the limit?

[nitro2]

Guys run 98 % nitro in fuel class land speed racing bikes..Most of these are N/A vintage engines..Many use modified carbs that literally just pour in the nitro...Obviously it takes some expertise..They are started on alcohol I believe...They use shorter larger diameter pipes than a gas engine...It does get loud on fuel but they are more interested in going fast than impressing the neighbors...More or less doubles the power ....

If anyone is running 98% nitro and are ONLY doubling the power, then they are WAY out to lunch. 4 times the power is straightforward, 5-6 times the power is a better aim, and that's naturally aspirated.

Nope about 2 to 2.5 times would be the best for vintage OHV bike engines.This is compared to a equal gas engine.. These are Bonneville and El mirage record holders....Triumphs, Harleys that need to run wide open for three miles without exploding and throw you off at 185 mph...

OK, well perhaps that's as much as those style engines can live with, without knowing what is going on in the cylinder. It's certainly not remotely as much power as 98% nitro can produce. 2-2.5 times the power is a very light load of 98% nitro. 2-2.5 times the power can be made with a lot less nitro % than 98%.

I'm not familiar with the rules at Bonneville, the "3 miles" you mentioned I presume that is the distance between take off and shut down or are you saying they are going 185 mph for 3 miles i.e. 185 mph for about 60 seconds?

[Dave Koehler]

I think the difference in the previously stated nitro power is history related.
How we got here is based on the time line.
Up until sometime in the 70s there were no welder magnetos and no giant gpm pumps.
With only 1-2 amp magnetos and 15 gpm pumps available a racer just could not burn (explode) copious amounts of nitro.
Hence everyone tuned up to the limit of the mag and pump.
I call this the air fuel tuneup period where the main jet played a part in tuning.

Fast forward a bit.
I am not sure who first realized what I call volume tuning nitro was the ticket over A/F tuning.
It kind of snuck up on everyone. The racer eventually ran no main jet and tuned with the nozzle sizes.
In a vicious circle pumps got bigger, racers jammed more in there up to the capacity of the mags.
2 mags was a leap forward.
Cool, now add more pumps or make the pumps bigger.
OK, got that now Dale wanted 3 mags.
The Glendora suits said no. I think whiner majority ruled here.
Too late, the genie was already out of the bottle.

Fast forward a bit further.
It kind of plateaued there until MSD decided to build magnetos.
Now they have more pump capacity than Hoover Dam limited only by 2 44 amp mags.
MSD has a 60 amp mag in the skunkworks room but the cars have more power now than the track and tires can hold so it just sits gathering dust.
Top Speed on too short tracks is also a concern here.

AND here we are today.
They have gone from 15 gpm pumps to what? 90-100 GPM and from 1 amp to twin 44 amp mags.
From 1000 HP (if that) to a calculated 11000 HP in the same basic engine package. That alone is stunning.

A/F versus Volume Tuning .
Volume tuning is hard to get squared away in one's head but that is what I call it.
It's possible to attach a ratio to it but it can make your mind go a bit numb.
Nitro is a barely contained and controlled beast.

Simplified
A/f tuning
uses a main jet and a reasonable?, sensible? amount of nitro to increase the HP without blowing the cyl walls out.
BTW, Reasonable, sensible and nitro should never be used in the same sentence.
Volume tuning:
Need more power? Add more volume going to the cylinder, light the fuse and run.

Massive amounts of nitro in drag racing is obviously doable but has a incredibly short fuse as in seconds.
Therefore jamming the same massive volume in a land speed car would be, dare I say it, problematic.

Caveat
This is not a definitive final word study.
It is just one observer's over simplified and somewhat redneck view of nitro racing history.