PLAN B

[the_blaze]

Man some of these numbers are wild this is still the bone stock TBI 350. So think low but not as bad as I was expecting. We will post results soon on IG then I'll tell you guys.

Here's a little video of it on the dyno

 

[the_blaze]

Longer pull video. It smokes only when he let's off but it clears up after a couple seconds. Not sure why it does that but my concern is on the lower side.

 

[max 02]

Interested to see the numbers now. For sure! Cool to have it on a dyno!

 

[the_blaze]

Dyno results are in. If you haven't yet please subscribe to our channel! Tell your friends! Help us hit 1k subscribers

 

[folkenheath]

The large tires can really kill the power reading on the drum. I've seen 70 HP difference in reading from 31s vs 36s back to back with no other changes. I don't know why, but I guess its because they calculate power based on accelerating a known weight of drum. And big heavy tires change that weight drastically. It can't be gearing alone, because I tried low range 2WD vs high range 2WD, and the difference in the reading was less than 10 HP for a 1.96:1 gearing change, which would of been like double the tire size, not 5" difference. So it seems to be mass dependent, and not so much gearing the way they calculate it.

 

[Truckman4life]

So....slap some super tiny car tires on before hitting the dyno so your printout looks good?

 

[the_blaze]

So I guess the video mentioned an ls swap. I didn't say anything on here when I got my donor vehicle because I was thinking I'd spend a couple years gathering parts, researching, bla bla bla... and I was waiting until I was closer. I guess a couple months later I'm closer now. So here is what I got. 6.0, 4L65E out of a 2005 yukon denali. I stripped it down and parted it out and ended up an even wash with me keeping all the parts I needed.

I had the 6.0 rebuilt and they put in a mild truck cam designed for torque, I also got rebuilt 706 heads to bump the compression to just over 10.5:1, topping this off with a trailblazer ss intake with 36lb injectors and hooker manifold knockoffs from summit. It should put down slightly more power than the TBI 350.
I had the 4l65 rebuilt and upgraded to handle more torque and HP. I added the advanced adapter vss sensor adapter so I can get the vss for the computer and keep the mechanical on my 241 for my guages.

Hoping to start this swap soon.

Photo dump:

 

[the_blaze]

Checkout our latest video on YouTube. @72gmck installs DIY4X shock towers and inner C supports.

We are just 8 subscribers from 1k, please share with your friends so we can hit that goal

 

[the_blaze]

So here's a weird one.... my truck has not been started in a few days. I unhooked my fuel lines and both the return and feed were under tremendous pressure that pushed out a ton of fuel. I had to tighten the lines up and have my cousin open the gas cap to release the pressure. The second he opened the cap the fuel stopped spraying. It still had a bunch of pressure even after dropping what seamed like a Gallon of gas until the cap was removed. I have a vented gas cap that prevents vacuum and i tested it it works. This is pressure like blowing up a balloon or air tank. this does not seem right. Any thoughts? What's plugged

 

[kgblazerfive]

Vent is plugged

 

[Truckman4life]

Wasn't this the one that had the weird tank sucked in issue? Sounds like you found the source of that.

 

[folkenheath]

Most likely the air can't get in when you pump the fuel out. Its probably not pressure, its partial vacuum.

Did you pump out that gallon or just drain it from gravity? If that is the case it's unlikely you could drain it without pumping it.

 

[the_blaze]

Wasn't this the one that had the weird tank sucked in issue? Sounds like you found the source of that.

My vented gas cap works on the vacuum side. In other words my cap doesn't allow it to suck in and crush. This this is like the tank is blowing up like a balloon. It was more than gravity feeding fuel it was under a lot of pressure up at the throttle body and right out of the sending unit until my cousin unhooked the gas cap to let the pressure out. When he did that you could hear the hiss and the flow stopped shootingout of the fuellines instantly.

 

[the_blaze]

Most likely the air can't get in when you pump the fuel out. Its probably not pressure, its partial vacuum.

Did you pump out that gallon or just drain it from gravity? If that is the case it's unlikely you could drain it without pumping it.

Definitely pressure, it was forcing fuel out until the second we pulled the gas cap. Both feed and return side.

 

[ashman]

Tank was quite a bit warmer than the last time you drove it, right? Could just be that. Like leaving a gas can in the sun?

 

[Fastereddie]

There should be a vent line that goes to your charcoal canister

 

[folkenheath]

Definitely pressure, it was forcing fuel out until the second we pulled the gas cap. Both feed and return side.

Ok, so you know it's pressure and not vacuum, then the vent line is definitely plugged somehow.

I think the vent line might have a float in the sending unit. If it was 100% full its possible the vent couldn't release until the fuel level dropped?

Some have found a valve in the vent line that hooks to the vacuum canister and potentially doesn't release without vacuum applied. But I'm not 100% certain how that valve works. Certainly worth checking for though.

 

[mrk5]

Some have found a valve in the vent line that hooks to the vacuum canister and potentially doesn't release without vacuum applied. But I'm not 100% certain how that valve works. Certainly worth checking for though.

That's what I had in the crew cab that I found after I had the bent up sending unit. I got rid of all that and put a filter on the end of the line.

 

[the_blaze]

That's what I had in the crew cab that I found after I had the bent up sending unit. I got rid of all that and put a filter on the end of the line.

View attachment 403643

What filter did you put on it? It's funny I just replaced that plastic part.

 

[the_blaze]

I guess at this point I can say there is no turning back