Project: Turbo 250

[jc70chevy]

Gud job on the build buddy and graduation

[NewType72]

Congrats to you and your sister adam truck sounds killer def need a road video with hd
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[71STPSDE]

Congrats on finishing school and the truck. So go and enjoy you the truck.

[longbed67]

Thanks to all of you for the congrats!

An update on the truck!
Well I was having difficulty adjusting the float level and it wasnt going down soooo I took both bowls off changed the jets took out the needle/seats and put it all back together because and well I was immediately able to adjust the fuel bowls to the correct level without a problem and have 3.5 threads up into the nut. I however still cannot drive it more than 6 miles because as soon as the engine warms up to full temp the engine is choked out because it is running rich, as soon as it cools down I can start it right back up... The carb started with 66 jets in the primarys and 73 in the rear, and I could only go 2 miles before choking out. I now have 64's in the primarys and 71's in the secondarys and still WAY to rich. So I have to order another jet kit, because the one I have only goes from 64-99 jet sizes. But lets put it this way people are breaking their necks to look at the truck the whole 8 miles I have put on it.

[Jebenubin]

totally awesome build man and kudos for finishing up your degree, you did amazing work! I love your attention to detail, all the little custom things that make that truck one-of-a-kind! I would love to see some final numbers on power once you get the carb dialed in. What rate of step up spring are you using? I had to change out the 9"hg for 3" and that made a difference in mine for sure. Course mine isnt turbo'ed just yet! Also was curious if you'd looked into a newer "carburator style" fuel injection...professional products makes one similar to MSD or FAST (wide band 02 self tuning) but it can handle up to 25lbs of boost. I know when I get mine rebuilt I plan on going fuel injection all the way.

[longbed67]

Thanks jebenubin! My spring rate in the distributor is mechanical and not controlled by vacuum. I have looked at the newer "carb style" fuel injection but is more money than I want to spend for it. I do think that will be the way to go on my next build though, when I am making more money!

ON a side note, this is the first time in 2 weeks or so I have had internet so just a quick update, I got it in tune a little better went for a nice 20 mile drive, and got about 3/4 of a mile from home and it killed out and ended up walking home getting my other vehicle and sister and had her pull me home, so I broke down and ordered a C&S carb today! On the up side Rodger said it should be about a bolt on and go setup for up to 10lbs of boost which is where I plan on keeping it at. I did get the box back on the truck and will be taking it over to my buddy's paint booth and getting it shot once I get the carb back and making the final touches in the next 6 weeks so it will be ready for my wedding!

[Jebenubin]

bummer on the breakdown man! I guess I wasnt clear in what I was talking about: what I was referring to was the step up spring on the metering rods in the carb. I cant remember what kind of carb you are using and maybe with a turbo-blow through design they are totally different, but in my edelbrock (dont hate, they're inexpensive) the metering rods and jets are all changeable and the rods are seated in the jet by vacuum. The springs that control this are rated at different levels of vacuum, so if you have a spring rated at 9" of vacuum the rods will tend to stay out of the jets allowing more fuel flow (rich condition) as opposed to a 3" vaccum spring witch keeps the rod down in the jet easier (more lean). Hope this makes sense...

[longbed67]

It was more of an annoyance than anything.... And well I wont have to worry about anything other than a final minor tweaks on the carb to better mate it with my engine. And blow thru set ups are run with Holley double pumper carbs. Vacuum secondary carbs do not work with blow through, because there is no vacuum once you start to get on the throttle which is why I thought you were referring to the distributor lol

[jlsanborn]

I'm for sure no expert on forced induction but would think the metering principals of the carby are similar. That double pumper has "power valves" right? Those would be the equivalent to the "step up" springs the previous poster is referring to. In both cases they are rated in inches of mercury. In naturally aspirated engines that would be considered the pressure below atmospheric (vacuum) but its really the difference between the air horn pressure and intake pressure (differential or pressure drop).

Truck looks awesome and its cool you're getting to shake it down! Can't wait to see the bed on it.

[longbed67]

Well I ended up making a quick decision change the other day, after I found out that without spending mucho buck and buying an aerosol carb from C&S I wouldnt ever be able to push this engine past 10lbs of boost max as that is all his non- aerosol carb would handle! And CSU would be able to take my existing carb and set it up so that I would be able to put more boost to it in the future if I wanted with only a couple minor tweaks! So now the carb is in California and I should have it back in 3 weeks! And to make the deal sweeter, he was a couple hundred bucks cheaper.

[cAlvis165]

Sounds great Dr. Longbed! Do you know what they do differently from what you can do yourself? I want to do my blow through myself, but if I'm going to have issues, maybe I should think about shipping mine off too... This is the link that I was referred to.

BlowThrough Step by step

[longbed67]

Otherwise known as the Hangar 18 mods... and yes I did these and yes you can get it to run and dial it in close enough to drive it around, but the problem comes in is getting it to run with flat afr's and smooth throttle the whole way through the power band. These mods just are not enough to cut it. For the $450 to have your carb setup properly from the get go it really isnt worth trying to half a$$ it by doing those mods speaking from personal experience. What they do is They machine the carbs for adjustable boost referenced power valves they machine it for different idle air bleeds, change out the venutri's....much of this stuff they have designed themselves with years of trial and error and r&d to perfect. Basically when you get the carb back, the carb is ready to bolt on adjust the idle circuits and go. How much boost are you looking to run and on what size engine?

[cAlvis165]

I'm going to try to boost an old IH 266 V8. Probably only looking to run 5-7 psi. The old IH are great for torque, but run out of breath pretty quick.

Boost referenced power valves sound pretty cool. I'm going to have to read up a little more. Finished reading Maximum Boost, by Corky Bell, and another turbo book by H. MacInnes. Both of these are a little old-school. But then, so is blow-through turbocharging!

[longbed67]

There is a lot of research to be done, and information is power... in more ways than one! Let me know if you have any questions! I would be happy to help.

[slick copper]

hey man! Hadn't been on in a while. Just caught up on the build lookin and sounding amazing! Gettin me excited about mine again. Keep up the good work.
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[longbed67]

Well lots has been done to the truck since I last posted and I have lots of pictures and videos to post that are still on my new smartphone and on the camera. I just took my board licensing exam today and am getting married on the 17th of august so I need to get her done before that so until then I will be limited on time to post up much of anything as to post on here it all has to be resized.
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[NewType72]

Well I hope you did very well on your licensing exam and congrats to the coming up wedding I'm sure you're going to have an amazing end to your summer this year with truck,wife, and accomplishments in your schooling. Will be waiting patiently for truck updates hope all goes well for you.
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[jlsanborn]

Congrats on all fronts man! Did you get the trans fixed? Get you carby back? Can't wait to see some photos

[longbed67]

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[longbed67]

Well here is an update.... Got the truck pretty much done, and was able to use it in the wedding. It dyno'd at a couple points shy of 330hp. I was featured on Extang's facebook page with my truck and have been talking with one of their customer reps about more.... And will be using the truck in a buddies wedding next weekend as well and will have more pictures to come!