8.1L install into 1978 K10…DONE

[DirtyLarry]

Well, I am excited as all hell to finally have this never ending project coming to an end and the electrical section doesn’t get much action so I figured I would share these videos here as well.

I still have some fine tuning that needs to be done to the engine controller but all in all it runs very well on the initial start up.

The tuner claims over 400 HP and over 400 lb ft of torque from a stock 8.1L running on a MEFI-4 controller and from what I can tell so far….it feels like they might be right! It has some major gonads!

The audio quality is pretty bad on my camera but you get the idea.

http://www.youtube.com/watch?v=avyjEr4bnGA

http://www.youtube.com/watch?v=SAYW1OXyEIU

[Pyrotechnic]

Sounds awesome! There's just nothing like raw cubic inches!

[SmokeShow]

very nice... is it just the angle of the shot or is the engine leaning a little towards the driver's side?

[68GMC454]

sweet.. sounds good

[DirtyLarry]

Originally Posted by SmokeShow

very nice... is it just the angle of the shot or is the engine leaning a little towards the driver's side?

Must be the angle of the shot as there is no engine lean.

[andresco50]

awesome congrats

[Eyegore]

Very nice, everyone came running into the room to see what was making the noise. Awesome job!!!!!

[semperfidoordie]

Looks awesome man and sounds even better

[DirtyLarry]

Thanks guys… Here are a few pictures of the final install.

I have a buddy coming over tonight to help lift the hood back on then need to charge the A/C this weekend.

It runs well enough to drive around to shake out the bugs but there is definitely fine calibration tuning to be done to address cold start issues and wide open throttle performance as well as a some underhood wiring clean up to be done. Also have an issue where the dual fuel tank switch valve causes a restriction on the return side causing the fuel pressure to run around 100 psi so the Pollak tank switch valve is bypassed at the moment until I figure out how I want to deal with that issue. Probably go with a transfer pump to transfer fuel from the LH tank to the RH tank on the fly as there appears to be no fuel tank switch valve with a 3/8 return line.

[74 C-30]

Very nice, looks awesome!
So any details on the motor? Is it just stock or have you done anything to it? Or plans to do something with it?

[cochino12]

SEXY!!!!!!!!!!

[BaddBusa2005]

Very cool, I want soooo bad to do a duramax swap into a 4x4 blazer.

[drbyrdman]

Nice! I have that engine in my 2500hd. Did you get a programmer for it. I would like to get more out of my truck.

[tvblazer78]

That is cool!!!

[DirtyLarry]

74 C-30, drbyrdman,

The engine is bone stock running a marine type Delphi MEFI-4 engine controller with tweaked marine calibrations. 420 HP and 490 to 505 lb ft of torque (similar to Marine) will be plenty for this rig so no other performance mods are in the plans. (Although, I have another 8.1L that will eventually find its way into my 68’ GMC that will get the go faster treatment)

This is the same engine that is in my stock Silverado 2500HD but the production vehicle PCM-32 engine controllers are constrained by emissions controls and torque management that only yield 340 HP and 455 lf ft of torque. You can tune the PCM-32 controllers to produce a lot more HP but I prefer the MEFI-4 route as the harness is less intrusive, the engine controller can be mounted right on the engine, and it runs OBD1 rather than OBD2.

You can actually feel a major difference in power between the Silverado and this truck. The Silverado is pretty slow but will pull down a house. The K10 is actually pretty fast and feels like it will pull down 2 houses (scary with a rear Detroit locker!) even though it still needs the fine tuning calibrations done.

[manimal]

That is flatout BADASS!
-Lance

[69face]

TOTALLY AWWESOME!

[jchav62]

Siiiicckkk!!!!!!

[DirtyLarry]

Definitely something different than the common 5.3L and 6.0L swap. What is nice about the 8.1L is it is direct bolt in. I used my existing 454 exhaust manifolds, engine mounts and even Centerforce clutch and pressure plate that was originally on my 350 then later on the 454HO. No need to fiddle around with changing engine mounts, plumbing new exhaust and dealing with an A/C compressor that is shoved down in the frame rail like the 5.3L and 6.0L requires….the 8.1L is definitely an easy swap in my opinion. More powerful too in stock form.

[abebummy26]

Flippin Sweet!

[72highlander]

that's sweet, i had that same based engine in a boat i had. ran like hell. look at raylar for performance goodies.

[drbyrdman]

can i put a marine controller in my 2002 2500hd??

[DirtyLarry]

Originally Posted by drbyrdman

can i put a marine controller in my 2002 2500hd??

Physically, yes….with a wiring harness change. You would lose the use of cruise control and a few other things so it would not be worth it. You can always have your stock Silverado engine controller reprogrammed to gain additional HP...probably not as much as the marine HP numbers as the Silverado still runs OBDII and needs to be emissions compliant.

[JCampbell]

Larry-

Do you have a "build thread" for this swap? Really been considering pulling the trigger on this swap for my dually.

[DirtyLarry]

Originally Posted by JCampbell

Larry-

Do you have a "build thread" for this swap? Really been considering pulling the trigger on this swap for my dually.

No, no build thread on the 8.1L swap. The install was simple engine R&R, as the 8.1L is a direct bolt in…..no drama like an LS engine. I ran it for the first year on a MEFI-4 GM Performance Parts RamJet/Marine ECM then changed it to a stock Silverado P59 ECM later. Don't ever bother with an MEFI ECM...they suck! That story does have a thread here.

Here is a great thread on an 8.1L swap into a 1ton 2wd dually by another member.