LSX help

[djw32]

Hello all,
I have searched through a majority of the gen III and lsx install threads, but I can not find acouple answers.

1. Does anyone make motor mounts that position the LSX in the factory location? I would like to leave my turbo 350 in the stock location(I do not want to shorten my drive shaft).

2.Has anyone hooked up there LSX to a carb setup? Is it as easy as it seems?

Thanks, David

[shifty]

1) There are a bajillion different mounts out there - I would try to find one that uses slotted holes instead of the round holes so you have the ability to slide the engine forward or back a bit.

I've heard a lot of good things about these ATS mounts, but I've never used them (they are NOT slotted!!): http://store.nexternal.com/shared/St...ID=&GalleryID=

They let you use the factory BBC mounts...BUT - BUT - BUT...when GM designed the GenIII platform, they pushed the mounting of the engine 4" forward from the stock location a GenII or GenI SBC would sit, so ... you need to take this into consideration. Bolting something into "Factory position" could actually put the engine almost four inches in a different place

(I hope this was straightforward enough an answer )

2) I've seen it covered in a thousand magazines, and there are a dozen threads about it.

Basically, you'll need to bolt up the intake and carb and get a spark control box. Cost on the control box is a bit spendy for my blood, but it significantly increases ease of install.

This is the box you can use: http://www.msdignition.com/ignition_33_6010.htm

$330 at that store (I DO NOT ENDORSE THAT STORE, SHOP AT YOUR OWN RISK).

There are other controllers out there.

Personally, if you want to do this easily, I think ...I'd get some adapter plates, bolt up the engine, the bolt the tranny to it (using whatever adapters/adaptation required), then move your crossmember and make a new driveshaft. Seriously - think about that - New driveshaft is what, $200, tops? Very easy to measure...

The reason I say this is because your concern seems to be engine mount, but mounts are harder to fab than a new driveshaft.

If I've learned one thing during my swap it is - When at a crossroads, Identify the easiest part to replace and replace it

Good luck, and please create a build thread and take lots of pictures when you do the swap! We all are really interested and want to help!

[Ackattack]

If ease of installation is the reason for going with the carb, I'd just get a aftermarket wiring harness which is very easy to plug in. Either way it will cost you some $$$ cause you'll have to spend the money on the ingnition control box. Plus the intake and carb. One of the significant benifets with going with an genIII engine is the EFI.

However you go, there are a lot of things to consider, and a lot are not cheap. Also think about the exhaust (headers or manifolds). Fuel pump also. There is no provisions for a mechanical pump so carb or efi you'll be running an electronic pump.

[shifty]

I've heard a lot of claims at the LS1tech forum of getting pretty damned good gas mileage out of a carb'd setup (14-16mpg). Now, that's not as nice as the 20-24mpg numbers I hear for a nicely tuned EFI setup, but ... it's still not bad for carb'd SBC.

[djw32]

Originally Posted by shifty

I've heard a lot of claims at the LS1tech forum of getting pretty damned good gas mileage out of a carb'd setup (14-16mpg). Now, that's not as nice as the 20-24mpg numbers I hear for a nicely tuned EFI setup, but ... it's still not bad for carb'd SBC.

I have also read that.

Shifty,
Your second post makes alot of sense. Good point on the drive shaft. Do you know of a website that shows the install/placement of the ats plates? I would like to get away with running stock exhaust manifolds for awhile

[shifty]

Unfortunately, I do not. I would recommend going to LS1tech and hunting around. Or click this link:

http://www.google.com/search?sourcei...:ls1tech%2ecom

Pay attention! Look at the "preview" text under each link - ignore the hits that talk about "Moser 9" rear end", it's just picking up crap from someone's signature. I found this link, which may be useful for you:

http://ls1tech.com/forums/showthread.php?t=844847

But also understand - most of the LS1tech guys - I swear, they all have 67-69 Camaros that they're dropping GenIII platforms into.

[djw32]

But also understand - most of the LS1tech guys - I swear, they all have 67-69 Camaros that they're dropping GenIII platforms into.[/QUOTE]

+1. I am one of those guys. The camaro is not ready for a motor...yet

[shifty]

Well, when you get to it ... if you're not already on LS1tech, you should get on there. In particular, lookup 69rsss and check out his very lengthy build thread, he's covered the entire 67-69 swap in explicit detail, and I think you will find some INCREDIBLY useful pointers from him. There are (of course) at least two dozen others who can claim the same, but I found his thread to be much more thorough than everyone else's and put into terms (with part numbers, etc.) that everyone could easily understand.

And good luck - I envy you. There is a guy here in north GA (Marietta?) that was posting on LS1tech recently that used the ATS mounts in his 67-79 F-body and he wouldn't shutup about how perfectly they put the engine in place.

[speed-racer]

I used Early Classics mounts for my '68 and am running factory 5.3 manifolds from a tahoe. I had to clearance a small amount of the frame on both sides, mostly on the bottom side so that the triangular shaped flanges would fit. I've heard a lot of people complain about their mounts, but I was happy with them.

[shifty]

My only complaint is small - if you're using the LS1/LS6 intake manifold, trying to find enough clearance for the MAF + intake tube + filter is tough. I would not be having this problem if I'd have used other mounts - BUT - with other mounts, it would have put my shifter way too far back IMHO.

[speed-racer]

I used the factory air intake from the tahoe and it fit perfect, it does not look as good as most, but it fits. It just depends on how good you want it to look. My truck is purely a driver.

[djw32]

Trying to find the perfect mount is stressful...I need to start PMing some guys

[Ackattack]

I made my own adapters. I used the 73+ stands and motor mounts. Then I just made the adapter plate from 1/4" thick steel I had around.

I don't have the engine officially in yet, but when I test fitted it, it worked well. I didn't have much options for moving the engine back, because of the placement of the AC compressor with the corvette front accessory drive setup I'm using.

I'll know shortly how it all fits.

[68GMCCustom]

are you going to put a gear vendors overdrive behind that turbo350? run fairly tall rear gears? or just try to stay off the freeways?

[djw32]

If I go with this motor, I may use the t350 with a gear vendor. All of this information is overwhelming.

[shifty]

It is a lot, but it will only overwhelm you if you let it. If you get overwhelmed, you're going to blow way more cash than you need!

Best thing to do is assess what you got and go from there. Draw out a logical path (flowchart-like), with most important questions asked first and least important asked last.

There are a few basic things to think about: Which tranny to use? Carbed or EFI? Which motor mounts and tranny mount? The rest is just the same as any other engine, I feel.

Example: You've currently got a T350 and a GenIII engine.

Will they bolt together w/o adapters?
If yes, proceed. If you find out that they won't, determine how to adapt them and the tally cost; if cost too high, consider another tranny like the 700R4, which is a non-electronic version of the 4l60e.

Result: Engine and tranny are mated.

Will I go carb'd or use stock computer? This will decide what electronics you choose.
If stock computer, do I hack my own harness or buy one, and who will tune my computer? If carb'd, what ignition controller should I use?

Result: Fuel source is determined, and you have all electronics required to generate spark (harness, computer, tuning).

Now that I have an engine that will run AND a tranny mated to it, how do I get it in the truck? This is where motor mounts and tranny mount come in.

Does my tranny mount have a single bolt mount or a two-bolt mount? If my truck is a 3spd, I need to cut out the 3spd tranny crossmember; if it's automatic, do I want to use the stock tranny crossmember or get the nice tubular one from Classic Performance Products which is super easy to bolt up? Which motor mount plates do I buy, and does it really matter which adapter plates I use? (if you have mount stands already, plates are the cheapest solution)

Result: You have mounts and can install the engine/tranny combo.

Once installed, will the stock driveshaft work, and does the driveshaft yoke I have work with the tranny I'm using? (test fit it!) If not, with the proper yoke sticking out of the tranny tailshaft approximately 1-2", what is the measure from the center of the u-joint hole to the center of the mid-u-joint hole on the gearbox so I can get a driveshaft fabbed up at a local shop?

Result: Tranny is mated to the gearbox, just need to figure out tranny linkage.

How will I deliver fuel to the engine, external pump or in-tank pump? Stock tank or aftermarket? Do I need a return line or a fuel pressure regulator? How will I adapt the fuel line to the fuel rail and/or carb? How will the fuel pump get power? If you use stock tank, you need external pump. If you go aftermarket, you can choose either internal or external. Make sure you know the gallons per hour required by the engine and also the fuel pressure required (for EFI, it's ~50psi fuel pressure to the rail).

Result: Fuel line is installed and goes from tank to engine.

From this point on, it's just small details - electrical wiring? - coolant hoses/radiator? - electric fans or not?

You know, I think it's like skydiving. You can sit in the plane overwhelmed by what is sitting in front of you, or you can jump out and enjoy it, possibly crap your pants, but have a good time while doing it.

The important part is to NOT get ovewhelmed, and don't overanalyze.

This is my experience. Everyone's is different.

Oh - and another thing - is GVOD really necessary? GenIII engine is just like any other SBC, in fact, it IS a SBC, so ... don't be overly worried about fuel economy. You can always go with lighter gears in the rear, or just use a tranny from the getgo that has overdrive already on it.

[djw32]

Thanks to everybody. Special thanks to shifty and 68 short step. Right now I am between the 350 ci with a weiand 142 or 144 blower, or I may plan on doing the lq9 motor conversion.

David

[68GMCCustom]

the blower would be cool....but just remember the GenIII/GenIV motors flow a lot more then the old SBC....and are capable of making considerably more power. An LQ9 with just a few breathing tweaks....will provide over 400hp... easily. Stroke it to around 400ci....and your approaching 500+. Use an iron LSX block, and build a small block 454...and get over 600hp....N/A.

[billyjo]

You could also put a blower on a GENIII motor also.

[68GMCCustom]

no doubt!

[Wasted Income]

I made my own adaptors for my 5.3L install, because I too, did not want to shorten my driveshaft. I am using factory silverado exahust manifolds and I had to grind the frame a bit to make it work. Minor issue. I wish I'd put an LSx in there years ago!!!