Putting a LT1 in a 86 Sierra?
 

I've got a 86 GMC Sierra. Original 305 is wasted so I'm considering tossing in a LT1. Anyone here ever done it? I tried to do a search but it wouldn't let me search for LT1.

I know the engine will physically bolt in, it's just the little stuff I need to know. Like, does it have a weird EGR setup using a seperate pipe coming off an exhaust manifold? What have people done for the fuel systems? Can a rear tank be mounted in these trucks, like from a Suburban (my truck is a longbed)?

If anyone here has doen it and has any info on it or even some pics it would really help.

Re: Putting a LT1 in a 86 Sierra?
 

You can put a Blazer tank in it like captkaos did.

http://www.captkaoscustoms.com/blazertank.html

Slonaker

Re: Putting a LT1 in a 86 Sierra?
 

As Slonaker pointed out, I am using a Blazer tank in both my trucks. The one that is getting the most attention is this one in this thread that the 6.0L is going it...

http://67-72chevytrucks.com/vboard/s...82#post1653982

Re: Putting a LT1 in a 86 Sierra?
 

Good tech article, thanks for the help!

Looks like a nice project ya got going there. Should be pretty sweet when it's done.

Now all I need is some LT1 info!

Re: Putting a LT1 in a 86 Sierra?
 

what kind of lt1 info are you looking for?

Re: Putting a LT1 in a 86 Sierra?
 

If you are using a late model LT-1, remember that the fuel injection will work best with a fuel pump that is installed in the fuel tank, not on the frame. The v-8 should bolt in like any other motor, but the distributor is on the front and it is VERY sensitive to moisture, (Don't wash the motor with water). The exhaust is basically a standard GM design, so the headers should hook up. You will have to get an aftermarket wiring harness from either Street & Performance, Howell Engineering, Painless Wiring, or some other supplier, to make the install easier. Look at a good set of new electric fans, or scavenge from the salvage yard for a good set. There are many ways to operate the fans for cooling, I would look for as simple of a set up as possible. Try looking at Centech for a wiring harness and controller www.centechwire.com

I presently am working to put a 90 Vette Tuned Port motor in a 1991 Chevy pickup, which will give me another 100 Hp over the enemic TBI that I already have. I am going with the "Integrator" setup that S&P sells along with their wiring harness. I have put in a set of "SPAL" dual 11" fans along with their controller so that I can operate the fans seperately. I am going to have to install a new fuel pump and some tubing to change the hook up, but that will be simple. The LT-1 is basically a later model of the TPI that I am installing and there is little difference in the basic hookup. The ignition and the computers are the difference.
I believe that if you look at the S&P website they have some data and install discussions on the LT-1 and TPI installs for you to review.

Re: Putting a LT1 in a 86 Sierra?
 

my freind is wanting to do the same in his 1994 gmc. However it is almost a direct bolt i for him

Re: Putting a LT1 in a 86 Sierra?
 

Does the LT1 have reverse flow cooling? If so what other modifications need to be done?

Re: Putting a LT1 in a 86 Sierra?
 

It's a LT1 from a 95 Camaro. It includes everyhting; intake, injectors, ECM, and the Camaro's harness. Lucky me, I build wiring harnesses for a living and do custom wiring so electrically it'll be a breeze.

My main concern is with the coolant system. I know it's a reverse system and I know the waterpump is cam driven, not belt driven. I'm assuming I can just use the truck's original radiator (original replacement anyway), but I want to be sure.

I'm also planning on swapping the cruise control system in. A/C will definatly be going in.

It would be nice if I could bolt up the serpentine belt system from my old 89 Suburban, minus the water pump of course. Hrmm....

Re: Putting a LT1 in a 86 Sierra?
 

How about dual turbos?
http://www.turbocustoms.com/index.htm

I have an article for an 83 with an LT1. Check it out.
http://www.hotrodlane.cc/PDFFILES/83chevyLT1install.pdf

www.hotrodlane.cc

Re: Putting a LT1 in a 86 Sierra?
 

Don't forget TPI!! TPI in a 71!!
http://www.hotrodlane.cc/PROJECTS/71...hevypickup.htm

Re: Putting a LT1 in a 86 Sierra?
 

This motor is an older model LT-1 with a Tuned Port on it. It is in a 1971 Chevy truck. You may have seen it in the magazine. It has a wiring harness from Street and Performance, as well as many o9ther parts.

Re: Putting a LT1 in a 86 Sierra?
 

For something as heavy as a truck, a TPI setup seems like a better solution than an LT1. God knows why GM never used TPI in the trucks in the first place instead of that awful TBI.

Re: Putting a LT1 in a 86 Sierra?
 

My Impala SS has the LT-1 in it and I would say that is amazing, however, there is a lot of similarities between it and the TPI "L-98" that I have setting on my garage floor. The horsepower ratings are similar as well as the design. The water pump and distributor drives off of the crank front on the LT-1, but that can be a pain in itself at times. The TPI setup is stronger than the TBI units, by far, but the TBI motors were put into trucks for a longevity situation. (Low horsepower and basic setup to keep the motor performing for a long time). I plan on changing that very soon.

Re: Putting a LT1 in a 86 Sierra?
 

The LT1 is a totally different animal then the standard Gen I SBC TPI L98 engine..the LT1 uses reverse flow cooling, as well as optispark instead of standard distributor.

Re: Putting a LT1 in a 86 Sierra?
 

Do you remember the older model LT-1 motors, from the 1970-72 era (rated at 360 to 370 Hp)? They were a SBC that was in the earlier style muscle cars, Camaro Z-28 and Corvettes. The LT-1 that is in the late model Impala, Camaro, and Corvettes was a take off on the designation, with the wonderful Optispark and reverse flow cooling to get the serpentine system involved. The design of the intake and the TPI throttlebody are similar to the Gen 1 SBC L98. The runners on the LT-1 intake and the intake ports on the heads make the broader horsepower band in the later "Gen II" LT-1, where the L98 flattened out around the 5000 RPM area. The blue truck that is in the picture happens to have the older LT-1 motor in it with Brodix heads and a S&P chromed tuned port. Does that clarify the discussion that I was eluding to?

Re: Putting a LT1 in a 86 Sierra?
 

Part of the confusion is the difference between an LT-1 and an LT1. The LT-1 was the designation for the old 350 small block from the 70s. The LT1 was the newer Gen II small block with the miniram type of intake. As far as the LT1 vs. L98 goes, the throttle body is very similar, but the intake is NOTHING alike.

The LT1 uses a large plenum area with exceptionally short runners. In fact, the only runner length is that of the intake port on the head.

In contrast, TPI uses a smaller plenum volume and a total of 25" of runner length. This creates a reversion wave that reflects back down the runner, then re-reflects to combine with the incoming air to help "push" more air into the cylinder. This works the best at the rpm where the reversion pulse is in phase with the main pulse, which is why the TPI builds such massive torque around 3200 rpm, with a tapering torque response on both sides.

Completely different intake technology, and as a result, completely different powerband.

Re: Putting a LT1 in a 86 Sierra?
 

YEP that is what I was talkling about, however, I didn't take the Engineering approach (since my Engineer is in the shop-Bad calculus chip)and go into depth on the design. Now for what I was talking aobut in the design characteristics that are the same. The basic design of the Gen II LT1 is that it IS a TPI style motor (the older ones had long runners and it has a short runner style), The Throttle boody design is relatively close to it's predecessor and the connections are the same. The Optispark design was a definite GM mess for some people and then on the other hand it works quite well fo others. If you were to install a L98 or a LT1 the basic needs are the same. The cooling system is a little different, but that is mostly in the engine design, the hookups will be basically the same. There s no problem with the water pump, due to the camshaft drive for it, that simplifies that part. The block is nota unique mounting design as is the "Gen 3" series motors. On those motors, to mount them in an early model vehicle, you have to get adapters for the motor mounts and a completely different set of headers. I also have one of those sitting in the garage. The LT1 is a good power builder and it responds to simple changes in air ratio and temperature modifications well. A good set of headers will wake it right up.