LQ4 6.0 replace a 305/350/383?-gctid340698

[Guest]

Just 'floating' an idea. If I'd have known this LS engine had the same bolt pattern as the ancient 305 I rebuilt I would never have done it. There are about a million 6.0 chev trucks out there...has to be some good deals at the wreckers.

Imagine: 360hp, OBDII fuel injected, one coil per cylinder ignition, wicked efficiency, gobs of torque.

I'd make my own manifolds with a spot for a 02 sensor (2 per engine) out of stainless and fab up some engine mounts....

Anything else preventing a guy from bolting one up to a 270/80/90?? Anyone tried it?

Chay

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Chay, that would be quite a challenge....... not just the exhaust manifolds, but perhaps FI mapping, and maybe a few other things, such as short piston skirts.

It would require being Closed System cooled also.

Sweet engine though. I actually know very little about it.



The Vortec chamber was definitely a hit with GM's SBC......, and apparently carried over nicely.



Note the piston deck in both the Reverse Dome............................................ and the Flat Top version.... both listed for the LS 6.0L.



Here's some info on it, of which you've probably seen already.

[dmcb]

Will the drive handle that much hp?

[2850Bounty]

dmcb wrote:
Will the drive handle that much hp?

Years ago, I spoke with two different Volvo Penta techs, each upon a different phone call!

Each informed me that the 250 drive will handle bursts of up to 200% it's rating.

Now this was for the 250, and I questioned it........, and that's why the second phone call.

So yes, his 270/280/290.... it should handle the power.... but I'd not get crazy with the throttle.

Chay's best bet would be what V/P installed behind the BBC.

The DP-C or C1 in the 1.78:1 ratio.... or at least the A or later transmission.

[SIZE]4 wrote:
But perhaps we're[/SIZE]

[Guest]

I agree, closed cooling. After running closed I feel it's the only way to go so for me it's almost repedative to say closed cooling.

There are lots of guys doing OBDII tuning, but if it's similar to what I've seen on the 305, there really is no retuning necessary. I did modify it, but it was just to keep it simple until I had some experience with it; I don't think it was necessary and is probably robbing me of some efficiency. Some may argue, but I've seen/used the stock 1992 305 programming and the spark advance at high load setting is +- 1deg from the volvo advance chart floating around out there. The fuel is rich enough stock for me. I'll leave that for another day though.

It sure is a tempting option.

If I had an engine go bad again I'd have to try a pair of these suckers!!!

I'd love two DPs, but $$$. I figure I could get a used 6.0 for 1.5K including electronics, but I have yet to prove it. I figure a 2000 truck with a blown tranny has to go pretty cheap, or go to the wreckers...

I guess they're really about 300hp each, there was a ho version (LQ9) which had 340hp. Anyway, 600-700hp ought to get the boat out of the water.

Chay

[2850Bounty]

Chay......

cfoss wrote:
I agree, closed cooling. After running closed I feel it's the only way to go so for me it's almost repedative to say closed cooling.

[COLOR]"#0000FF" wrote:
With the aluminum cylinder heads, you have no choice. [/COLOR]

There are lots of guys doing OBDII tuning, but if it's similar to what I've seen on the 305, there really is no retuning necessary. I did modify it, but it was just to keep it simple until I had some experience with it; I don't think it was necessary and is probably robbing me of some efficiency. Some may argue, but I've seen/used the stock 1992 305 programming and the spark advance at high load setting is +- 1deg from the volvo advance chart floating around out there. The fuel is rich enough stock for me. I'll leave that for another day though.

[COLOR]"#0000FF" wrote:
Ah... but piston selection plays a very important role in this.

The non-quench chamber design will only handle so much TA...... or you Detonate.[/COLOR]

I'd love two DPs, but $$$.

[COLOR]"#0000FF" wrote:
The DP's (with good 5.7L's) will give you more performance than the 6.0L will with the single prop drives. [/COLOR]

[Guest]

I agee with your points.

1) Lots of 99-2000 LQ4's had iron heads. I guess you'd want to change the head gaskets

2) I agree you can only have so much advance, given a certain load, combustion chamber temp and air/fuel ratio. I also agree quench pistons will help to push the TA higher. I do think that these factors will be taken into account in the standard tune. These engines are meant to work hard in a truck. My old man's sure does when we pull my 7k 5er.

3) The DPs would be $3.5 each at least, for unknown quality items. Then I'd need a pair of 350's to drive them. Sound like too much for a 6k boat!

Chay

[Guest]

If you have the resources, DO IT!!!

If youre running in fresh water only, you wont need closed cooling.

Also, the second o2 sensor in each bank is for the computer to verify the cat's are functioning. You will be fine with the first o2 sensor in line, in each bank.

You can also run in open loop (not utilizing any o2 sensors) its just not quite as effecient. If you want to pass coast guard/park ranger checks, you need to use as many OE marine accesories as possible (although most of those goons dont know what they're looking at).

Good luck, and keep us posted if you do the swap.

[Guest]

just purchased a 88 1950 with a siezed 305 wich is scrap look forward to see how u get on.

[Guest]

It's a 'future' idea for me. My engines are still functioning ok. I'm just trying to figure out if there is any good reason why it wouldn't work.

Right now it seems that the trickiest thing would be to get the splined adapter thing to bolt to an unknown flywheel. If the holes aren't there you could have them machined in of course. Then there is clearances in that section.

Chay

[2850Bounty]

cfoss wrote:
It's a 'future' idea for me. My engines are still functioning ok. I'm just trying to figure out if there is any good reason why it wouldn't work.

Right now it seems that the trickiest thing would be to get the splined adapter thing to bolt to an unknown flywheel. If the holes aren't there you could have them machined in of course. Then there is clearances in that section.

Chay

I don't kow if GM made any changes to the rear engine flange, or to the flywheel external bolt pattern (if you're talkig about the Borg Warner drive coupler, for example).

If you are talking about the cranksahft flywheel flange, http://"http://ls1tech.com/forums/ge...S1 tech forum.

I think you'd have other issues that would be of more concern...... short piston skirts, for example.

[Guest]

Drive coupler sounds better than splined thing eh? How about three bolted splined thing?

My idea would be to use the LS flywheel rather than trying to use the 305/350 flywheel. I don't know if they are different or not. Balancing etc may be different, then there is the starter mount and access to consider. A person may have to do some machining on the flywheel cover.

I think the thing to do would be to pull a flywheel cover and associated parts and head down to the wreckers and see how it fits up.

We'll see how the engines hold up this year... I may have to push the stbd so I can pull it out

What's the big concern with skirt length? Do you feel excessive piston slap will occur due to the shorter length? The thing is, as much as I run my boat it'd take a long time to really cause any problems, and a new used short block is like $800 so who cares!

Chay

[Guest]

I found this on Chevythunder.com with respect to ls1s with old trannies:

Transmission Retrofits

Installing a LS1 engine with another transmission such as a early 200/700R4, THM350/400 will require the installation of flywheel GM part number 12551367.

If using the F-body and C/K trucks with the 300 mm bolt pattern will require the flexplate with PN 12563136.

The 4L80E or 6 lug converters will require PN 12551367. This flexplate is flat and will require the use of a spacer (PN 12563532) and bolts (PN 125635330 which is included with flexplate assembly.

If using a early manual transmission will require, which will use a 11.7" (298mm) clutches:

PN 12562765: 6 speed flywheel assembly

PN 12561680 Early style 4 speed flywheel

The LS1 crankshaft is also shorter relative to the bell housing than the earlier small-blocks. Special pilot bearing PN 12557583 is needed to compensate for this difference.

As our setup is close to the setup of a manual transmission, I'd expect the 'Early style 4 speed flywheel' part number to apply.

Looks like there is a solution to this possible issue.

Chay

[Guest]

1 More cool thing you could do. Some of the later LQs were fly by wire throttle. You could conceivably integrate the throttle resistor into the existing control lever assembly and delete the throttle cable assembly.

With 2 switches (3pole setup) you could have dual throttle stations, no problem. You'd have to safety them as to not switch when you don't expect it though. A bit tricky.

I guess I'd tend towards the mechanical TB, KISS and all.

Chay

[2850Bounty]

Chay, have you considered becoming a NASA employee? They love preposterous and expensive ideas. :kidding