macs_forever

WHY: I'm a 43 year old man with a family. My son's wheelchair fits in the trunk. I want the ultimate daily driver/ vacation cruiser. It's better than a pea green Wagon Queen Family Truckster.

Objectives:

• 0-60 in less time than it takes to fry bacon in the microwave
• 27 mpg or better on the highway
• 20 mpg or better in town
• More than 180hp
• More than 225ft/lbs of torque
• A lot more torque between 800 and 3000 rpm
• Be able to run the fuel of the future (E85)
• Avoid being run over when entering the DC beltway (I-495)
• The ability to put rice burners in their place (at the back of the line)
• The ability to squeel the 255/55-17 tires (at least one of them)
• Re-live the good ol' days when I used to build SBCs, only now I can afford to do it right.

The old 305 tbi has done it's job but I want more. It gets 27 mpg on the highway, but less than 10 mpg in town. My daily driving is a combination of stop and go traffic and busy highways. I drive 120 miles a day. I was driving a grand prix with a 3100, but that is going to be my son's car as soon as I put a new transmission in it. This leaves me with the Caprice. My wife said "Why should we buy a new malibu and go back to paying car payments when you could spend less on rebuilding the grand prix and Caprice". I said "OK!"

Originally, I was looking at an Gen I/II engine to rebuild, but the LS2 block isn't that much more and it's aluminum. With the LS2 I can have VVT and DOD. The only way to get more power out of a Gen I/II engine without loosing mileage would be to build up a 283 or 302. I looked at turbo-charging a 4.3L vortec v6, but that costs a lot more than a LS2 based motor. I don't think the odd-fire v6 would last as long either.

I'm going to use a LS2 block and L92 heads new from GM. I was looking at using a 4800 crank, giving a 4" bore x 3.27" stroke making a big bore 5.3L engine (almost identical to the old 327), but no one makes a forged crankshaft with 3.27 stroke. I'd be stuck with factory 6.278" connecting rods too.

What I know I am buying:

• LS2 block
• L92 heads

I am open to suggestions for the rest. I know my way around Gen I motors very well. While all this new stuff is cool...I've got a lot of catching up to do. If any of you have surplus parts to sell like exhaust manifolds and intakes, I'd be interested. I plan on spending the bulk of the money on the engine internals. Even with stocker parts, the new engine should be a significant improvement. A bone stock 4800 would be a significant improvement!

Thanks,
Keith

98Camarod

iTrader: (43)

Sounds like you have yourself a plan. But why not buy a motor that is complete with the wiring harness? If you plan on buying everything seperate you will spend quite a bit more money. Take a look at the for sale section, there was a guy that sold his cammed ls1 with wiring harness for 3k. Its pretty hard to beat that price.

RPM WS6

iTrader: (3)

Moving to Conversions section....

cherryelky305

iTrader: (2)

Amen! Even a truck motor would be fine, and they usually go for less. Only real difference is the iron block. If I were you I would be looking at used motor's and wreck motor's at the yards.

95GreenZ28

iTrader: (70)

I pieced mine together and it was more expensive and took longer. The good thing is I learned how to completely build it up Good luck on your project man. You will def get lots of help in this section if needed

G-Body

iTrader: (4)

You may want to look into buying a complete pull out instead of piecing the motor together. LSx parts are a lot more expensive than the stuff for gen I SBC`s was. I had to buy bolts for the starter and they list for $7 each. Overall it seems to be a lot cheaper and easier to buy a complete engine.

Shouldn`t be too difficult to swap into the caprice though, those things have huge engine bays.

macs_forever

Thanks All, but I'm going to piece it together. Mainly because of my needs. If I was going to buy a pull, I'd get a 4.8 truck motor. It may not have bone crushing torque, but it would get better gas mileage and still have more torque than the 305.

My needs are a little different than most of the folks here. The caprice is so high geared, I'll rarely see 3000+ rpm for more than a few seconds. I need a strong pulling motor from idle to ~3000 rpm but not much higher. The more I think about it, I could be OK with a cast crank and stock rods.

I want an aluminum block. it's hard to get an aluminum pull right?

cherryelky305

iTrader: (2)

thats two parted. Its hard to get an aluminum pull from a truck but getting an aluminum pull from a car is easy.

philntx

iTrader: (8)

This would be a good starting point:

A new 2008 6 liter with a 6L90E trans:

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=011

macs_forever

I love the 6l90 transmission. THAT would fix the slow acceleration from 0-60 with a decent engine. That one has a transfer case on it though. How much of the tail would I have to replace to make it 2wd? The engine is a problem. Everything I can find on the LY6 says it's cast iron. It's a truck engine, so it will have a cast iron crank. The intake would have to be replaced. It would be worth it if I didn't have to pour 3 more grand into it to make it what I am looking for.

I'm beginning to realize that my initial question was too vague. Now that I know I'll be using an LS2 block and L92 heads, I'm looking for suggestions on the rest. Let's start with the Crankshaft, rods, and pistons. Assuming I will eventually put DOD and VVT on the engine, what are my choices?

Crankshaft:

• should be forged for strength right?
• I don't want a "stroker" will be using either 3.27" or 3.622" stroke crank
• what's the best bang for the buck choice?
• Minimize weight, must not sacrifice durability.

Rods:

• No choice if 3.27" crank is used right? Must use stock 4.8 rods?
• Which is stronger/lighter? H-beam rods or I-beam rods.
• Are GM LS7 Ti rods worth the extra cost?
• what's the best bang for the buck choice?
• Minimize weight, must not sacrifice durability.

Pistons:

• What are all these coatings?
• Will I be forced to shave the heads or deck the block for 10:1+ compression? L92 heads have 70cc chambers.
• what's the best bang for the buck choice?
• Minimize weight, must not sacrifice durability.

itslow

iTrader: (4)

What you're trying to build doesn't seem to match what your goals are. It seems to me that a complete LQ9 pull-out from an Escalade, Denali, or Silverado SS would be an excellent choice. Swap to a LS6 intake setup and whatever accessory drive is needed, and drop it in the car. You don't need a forged crank/rods, coated pistons, and high-flowing, big runner L92 heads for a 800-3000 rpm family hauler.

If you want the VVT and DOD, buy a new crate or pull-out engine with those capabilities built in. You will find it cheaper to do it up front than later on (although I suspect you'd decide later on you don't need such features).

G-Body

iTrader: (4)

Why would you replace the truck intake? It sounds like you are looking for low RPM torque which is exactly what the truck intake makes. The truck intake will make more HP/TQ than any of the car intakes until at least 4000rpm, from what the truck guys say it is not worth replacing the truck intake unless you are planning on spinning more than 6000rpm a lot of the time. The truck intake is like a old school tunnel ram, really long runners so it makes more torque, but they have a small cross section so it makes torque down low instead of at 3000-7000 where the old SBC carb tunnel rams made torque

I don`t see you having to replace it because of hood clearance either, the truck intake fits under my El Camino hood, and I am sure the hoodline on a caprice is at least as high if not higher than my El Camino.

kossuth

iTrader: (12)

Well, I helped a friend of mine do a 95 caprice swap and I live up near Frederick MD. I'm gonna echo what others have said. Get a complete pullout it's cheaper. Modifying an existing fbody harness is the way to go. The gauges and such for the 95 weren't a problem, the 91 may or maynot be the same. Street and Performance makes mounts which work well with the 95, should work with the 91 as well. Hope this helps

Verz

iTrader: (21)

I also think your goals dont match your build plans. The truck intake and LQ9 heads will give you the low end torque that you are looking for verses the L92 heads and L76 intake. I will echo the "buying a pullout" will be the best route for you.

macs_forever

Your point has some validity. I don't need a forged crank/rods, etc for 800-3000 rpm (don't assume the objectives equal the wants ). If I can get a wide ratio 6 speed auto, DOD and VVT may be a waste of time. I don't have a full understanding of DOD yet. I know you have to have the right block and lifters, but I'm not clear on the mechanism that actuates the lifters. Kind of the same story on VVT. One thing that concerns me with VVT is that it looks like the camshaft must be designed for it. I don't know if after-market cams are made that work with VVT.

Installing a crate motor wouldn't provide me the same sense of accomplishment as assembling my own. I don't want a motor with a warranty because every time I take my car to the dealer, they screw it up. I don't need that kind of aggravation.

<>
Since I'm new here, I'll provide a little introductory info...

I'm a computer systems architect by trade (read old, experienced computer programmer). I LIKE designing and building things. I got a degree in computer programming because I didn't want to be a mechanic, working under cars in the AZ sun when I am 50. Programming is like building engines except you don't get greasy, it generally pays more. I've never given up mechanics. I'm the only IT professional I know that owns a milling machine and repairs his own cars. The funniest comment I've heard from coworkers is "I used to work on my own cars, but I can't do it any more because they are computerized." My reply tends to be some variant of "Don't you program computers for a living? Don't you have some sort of IT degree? These are simple 8/16 bit computers! If anything, they have made it easier to work on cars!"
</>

Back to the build... I am very interested in minimizing reciprocating and rotating weight. I'm very interested in lighter Pistons and rods that will work in an every day driver. The crankshaft can be cast, but most light crankshafts are forged or billet cranks true?.

Engine weight should also be minimized. The current 305 weights ~575 lbs. An LS2 should weigh ~460. I've always wanted a aluminum block. I'm getting an aluminum block.

If I'm going to just buy and tie, I could spend $1k on a 4.8 and use the rest to buy that cool 6L90 transmission. That would be a big improvement over what I have, but it won't make me happy (I think).

Last question for now: Do I HAVE to notch the cross member for the LS2 oil pan? I don't have cutting/welding gear here in MD. this could be a big problem. I read another thread about putting an ls? in a caprice. It looked like he cut hunks out of the frame to make room for headers.

kossuth

iTrader: (12)

Mac, let me offer alittle insight and please don't take this offensively because I know you're just testing the waters here. The factory rods in the LS motors are what are called "cracked" rods. They are some of the stronger rods that GM has used in a modern engine capable of handling 550+hp. Do you need something forged? Granted the rod bolts themselves could use upgrading but that is an easy task which doesn't require resizing of the big end of the rod. From about late 01+ the LS1/LS6 motors and I think the truck motors have coated pistons. The coating is more to hide piston slap than anything. Also does the telflon coating on the skirts really buy you that much power? The stock crankshafts are damned near indestructable in the LS motors with guys pushing over 1200 hp on em. Do you need a forged piece here? The only tricks are the DOD and VVT. Now, I have no idea how the VVT works on the LS motors, I just haven't been keeping up to speed on that. But the DOD, you can do it somewhat easily I think, it's just mostly the PCM I think. The major kicker though is you need a PCM from a DOD vehicle and you might need the tranny that goes with it, but I'm not positive. Also tuning that PCM, how difficult is it and has the aftermarket ventured into that realm yet? Just something else to think about because I don't know if anybody has worked out how to tune those PCM's yet being they are relatively new. If money isn't an object then by all means go for it, but I can't imagine the amount of dough you'll wrap up in it just in parts and possibly being a ginnie pig for something that is untested. Personally, I'd put a 4.8 or a 5.3 in it with a 4L60E and run it if all you want is a DD. They are plenty available and are good on fuel considering the size of the trucks. It's up to you though.

macs_forever

No offense taken. Something that has kind of tainted my point of view is a desire to make an engine similar to this one. I'm going to move toward building an LSx version of this motor. It really seems like torque has more to do with cubic inches than simply stroke. If stroke alone were the key, the 305 would have been a good street performer.

The only problem with cracked rods is that they cannot be reconditioned once they become out-of-round.

Updated parts list:

• L92 block (bored to 4.155)
• L92 heads -- they are CHEAP, with huge valves. I can't resist
• 4.8L cast crank -- Need to locate a source
• 4.8L factory rods -- Need to locate a source
• Pistons that provide 11.0:1 with the above combination.
• 6L90 transmission -- need a source
• Stock L92 exhaust manifolds (the wife hates noise. Maybe I could port them?)

Kossuth -- did your friend have to notch the frame to get the LS engine to fit? I live near Solomon's island, MD. I wish we weren't so far apart. I'd like to see your friend's caprice.

G-Body -- No problem with the truck intake if it would fit, but I don't think it will. My caprice has less hood clearance than a '72 Malibu that I used to own. I'm just assuming the truck intake won't fit.

Anyone -- Please PM me if you have a good 4.8L crankshaft or rods or know of a source.

itslow

iTrader: (4)

The iron LQx engines weigh less than your iron SBC, FWIW.

The 6 speed automatics will more than likely require re-working of your transmission tunnel (requiring welding). You will need to notch the crossmember or modify the oil pan. The accessory drive may also require notching the crossmember.

There's a LOT more to the swap than just building up the engine. I guarantee you'll have a high level of self-satisfaction knowing you did all the rest of the swap yourself, even if you buy a pull-out.

There are more actively posting guys on the Impala SS Forum who've done the LSx swap into the B-Body than here on LS1Tech. The would be better at answering the actual swap intricacies, whereas, LS1Tech would serve better at answering questions about the engine itself.

http://www.impalassforum.com

Additionally, why are you stuck on the short stroke? If you're going to be building this engine from scratch and torque is your goal, go with the longer stroke. Once again, you're build doesn't seem to match your stated goals (low RPM torque). Why don't you tell us what you're actual goals are for the engine?

bhop42

iTrader: (2)

I am swapping an Ly6 6.0 into my 96 Impala right now. The only Ls oil pan that will clear the crossmember without notching is the truck. Only problem is that the sump at the rear of the pan is to low to the ground and also the front of the oil pan slightly rubs the steering linkage underneath the vehicle. I went ahead and ordered the Moroso LS1 oil pan from Jegs for $220 and I am modifiying the stock pickup to fit. A very good solution for your goal would be to buy a Ly6(iron block approx 65lbs heavier) or L76(alum block) engine. The Ly6 comes on 2007+ New body style Gmc Sierra and Silverados 2500HD's w/6 speed automatics and the L76 comes on 2007+ New body style Gmc Sierra and Silverados 1500HD's w/ 4 speed autos. These engines already have the L92 heads and the only thing you will need to do is swap the truck intake(wont fit I tried) for a L76 car intake and modify the truck accessories to clear the intake. I bought my engine for $1500 with all accessories,harness and computer and could have bought the tranny for $1300. All I have to do is add a camshaft and I am at 500hp reliably. BTW the L92 block can't be bored out to 4.155 and if you are referring to the Lsx block then you already failed one of your goals (alum block) because it weighs more than your standard iron block. So based on your original goals "Objectives:
0-60 in less time than it takes to fry bacon in the microwave
27 mpg or better on the highway
20 mpg or better in town
More than 180hp
More than 225ft/lbs of torque
A lot more torque between 800 and 3000 rpm
Be able to run the fuel of the future (E85)
Avoid being run over when entering the DC beltway (I-495)
The ability to put rice burners in their place (at the back of the line)
The ability to squeel the 255/55-17 tires (at least one of them)
Re-live the good ol' days when I used to build SBCs, only now I can afford to do it right." I would buy a L76 engine, buy a 6 speed auto, ditch the DOD and keep the VVT, and add all boltons. You would have over 420HP, be very reliable and get great gas milage. Another thing about the 6l90 tranny is that with the low first gear, you could use the stock gears.

macs_forever

All -- Thanks for your input so far. Please don't take it badly if I don't heed some of the advise you provide. I am totally new to the gen III/IV engine series and all advice, even advice that is not accepted is helpful. I'm doing a lot of reading and planning at this point. Plans will change as I learn more. If I goof up, I'll admit it and you can say "I told you so". It wouldn't be the first time in my life that I was wrong.

itslow -- Thanks, I'll post over there and get more info on the frame. When I first started, I wasn't planning on too many car specific mods. I thought it would all be about the drive train.

The Speartech thread implies that the 6L80/6L90 may fit in the caprice. What transmission did your friend use? I could stick with a 700r4 to leave the trans tunnel stock I guess. Isn't the 700r4 and 4L60 basically the same transmission?

I'm not stuck on having a short stroke per se. I want a bore big enough to unshroud the valves but I'm trying to limit engine size to limit the size of the beast that must be fed. Assuming a constant and equal engine speed (like cruising down the highway) for 2 functionally identical engines, let's say 5.3L and 6.0L gen III/IV engines. The larger engine processes a larger volume of air and must use more fuel to maintain a 14:1 air to fuel mixture. There are many things that enter into the mix, but the basic principle holds true.

I am making a leap of faith that a 5.5L Gen IV engine is so much more efficient than the current 5.0 that I won't see a negative impact on fuel economy. For the 2.16"/1.59" valves, the bigger bore prevents shrouding. I could use heads with smaller valves, but they cost more and won't work as well with E85. If I use the longer stroke too, I'm taking an even bigger leap of faith. If I implement DOD, a longer stroke isn't as much of a problem.


bhop42 -- Has anyone tried the marine pan? The linked doc claims it is shallow, but I don't know if it is shallow enough.

You are correct on the bore size, I confused the specs of the LSX and L92 blocks. Bore will be 4.060, Stroke 3.27 =5.5L or 339cu. I changed my mind about using a LS2 block prior to my last reply because it could only be bored to 4.020.

All -- No one has commented on piston manufacturers yet. What have you guys used so far? With an LS2 block, LS2 heads, and 4.8L crank, flat top pistons yield a compression ratio of only 9.4:1. Does anyone make dome pistons for gen IV engines? If your engine has 10.5:1 compression or higher, do you have to use premium? Anyone able to use high compression with low octane fuel?

I plan to use E85 as much as possible, but it's not too prevalent yet. It's only sold at one place in DC right now.