Budget hi comp high(er) hp motor build

Indeed... I often laugh at the stupid stuff I write...

I probably need to hire an editor who'll work odd hours when I should be sleeping or not drinking...

HA!

Oh... someone mentioned to me that stuff like this came under the category of "domino modifications"... where you did one, then hadta do another to get that to work, then another so that one worked and on and on... until you were disenchanted or your money ran out... or both!
 
Lots of progress and maybe a pic or three..

Been off for the week and plugging away at the racer. New BV head installed. New 12+:1 comp pistons installed. Dual DCOE's.... installed

Let me iterate, what a PITA it is to install those things. No seriously, what a PITA. I've spent a good part of the week just on getting them to fit. OK, rant over.

Set static timing, and checked compression. After some fiddling, it fired up. Well, it fires on 2 and 2 half cylinders. Seems the pass side carb has no vacuum to pull the fuel thru. If I block the stack, and release, fuel pours out of the stack. This happens on both venturi's. Also the exhaust pipes for both 1&2 cylinders aren't heating up. The thing is, it doesnt sound like its only running on 2 cylinders. It sounds like 3 and 4 are working just fine and 1 and 2 are lean. Anyways, will plug away at it tomorrow. I think its either a vacuum leak or carb tuning. Any help would be greatly appreciated!

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Were the carbs rebuilt?

Like is it possible the venturi is not in correctly and the fuel port is blocked. It seems to me it is possible to have it out of rotation and block the passage. Its a leap but give it a check.
 
Mounting angle

Hey Brian,

What is the correct mounting angle for a DCOE. If there is fuel running out the air horns, could these be tilted downward? I thought they were supposed to be tilted upward like 2°-5°or something.

Just a thought.
 
Paul Valente said:
Hey Brian,

What is the correct mounting angle for a DCOE. If there is fuel running out the air horns, could these be tilted downward? I thought they were supposed to be tilted upward like 2°-5°or something.

Just a thought.
Click to expand...

Fuel only comes out of the horn side when I block it with my palm. There is little to no vacuum on either barrel.

FWIW, I did not set the carbs up yet and just downloaded the setup procedure from Redline. I'm hoping that the idle speed screws are set all wrong.

I'll have more info later this morning when I dive back into it.
 
Rooster said:
Fuel only comes out of the horn side when I block it with my palm. There is little to no vacuum on either barrel.
Click to expand...

Just trying to help. The fact that the fuel would rather run out the air horn rather than into the intake seemed to indicate to me that the carbs are tilted down. Plus, other set ups I have seen just seem to have a lot more of the cross-beam cut away than your car has. I know Brian (DallaraX1/9) knows the correct angle so I thought that may help you at some point... maybe that's down the road a little. :)

Any chance you have the spark plug leads for 1 & 2 swapped?

Good luck!
PV
 
Thanks to all

I found the issue, it would seem I needed to make sure the carbs are atleast somewhat set up before starting. I noticed that the drivers side carb was cracked open alot more than the pass side. Once I figure that out, and set up per the Redline instructions, everything acted as it should. I still have alot of tuning to do, but I have adequate draw across all four inlets. New step is timing, I'm getting pre-detonation and I think I may have a slight vacuum leak. Still, it's progress!

I'll post up a video once I take one.
 
Hey Mike... TWO things...

1. Is there a "balance port" that runs between both sides of the manifold... between ports 2 and 3? If not... I would make one or drill one as this HELPS to insure all four cylinders draw about he same amount of vacuum. I said nothing about it earlier because the problem seemed so severe and...

2. This thread has gone on for sooooo long and the way I have my browser set up (CORRECTLY) I hadta scroll way down to see that someone actually posted something against it and in a proper order. C'mon soldier... square away... as us sailors would say...
 
I can't believe what Paul can remember

Yes, I had to have the manifold milled (I had forgotton that one) to keep the carbs from dripping fuel on the exhaust header. It would take me a bit of time to find the drawing. I don't post too many studies anymore because of all the unasked for commentary, but this may help on the tuning - remember its free and you don't have to use it:











 
This weekends fun!

Spent 2 days racing at SLMP (ST Lawrence Motor Park). Its a shifter kart track that lest auto clubs rent it out. Here's a few video's

https://www.youtube.com/watch?v=QbYIv3o-QJo
https://www.youtube.com/watch?v=VncDp55cCKY

And here's where the clutch slave went. Completely popped the slave piston out of the cylinder.

https://www.youtube.com/watch?v=s4-lVcFHIcg

All in all, the Booger performed well for its first time on the track. I'd like a tad more power, and maybe different gearing. Power might be resolved with a good tune by someone who knows what they are doing. One thing I'm noticing is that I spin the inside tire on the tight turns, so I might have to explore a limited slip diff or even welded spider gears. No faults other than the clutch slave and a loose alternator wire that prevented the small (Odyssey PC680) from charging. Not a big list, but may take some time. Also, out of the 7 runs I made, all but the last had a "Victim" in the passenger seat! They all said its better than a ride at the fair!
 
Speed is about not coasting...

Listen to your videos and note how much time is spent with the car coasting, meaning you are not on the gas.

You should either be on the gas, either full on or maintaining speed, or on the brakes. When you cost you can in your mind start counting seconds you are throwing away.

The car looks and sounds great, would love to see the tach hooked up so we can see what RPM's you are running and shifting at. What cam are you using again?

Great job! Looks like a heck of a lot of fun!
 
Thanks!

And the tach is hooked up. I'm still breaking in the motor so I wasnt over 7k rpm. It seems to have a sweet spot around 5-6k rpm. With a momentum car like the Booger, you have to coast (actually not coasting per say, just neutral throttle), it's not a point and squirt

Also, at this event, its 1 warm up lap and 3 timed laps followed by a cool down lap. So you gotta watch after the first lap to see the action.
 
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