New to LS Engines, have some ?'s

**RCcola55** · 03-08-2009, 08:15 PM

Im in the process of designing/buildning a tube chassis ranger w/ its sole purpose to be offroading. I have decided to use a LS1 as the powerplant in this project and have a few ?'s about these motors. Now I am by no means new to building motors, I just dont have a lot of knowledge on the LS line, so any suggestions would be greatly apprecated!

Which yr is the best platform to build off of?

Im looking for around 475hp at the crank and possibly using 100 shot of spray on top of that. What heads, cam, intake, injectors, headers, etc would I need to look at to reach this goal. Also would the stock rotating assembly stand up to this kind of power.

When I find the motor Im going to use, what all do i need from the donor, i.e computer, harness, throttle control, O2 sensors.

Can these motors be converted to mechnical throttle of is even worth it?

Recommendations on who to tune the computer.

What does it take to adapt to a th400?

and any other info that could help this project out.

Thanks and Gig Em'
Ryan C.

**c5z28** · 03-08-2009, 08:30 PM

Sad to say but alot more informative answers on ls1tech. I will tell you what I do know,
475 at the crank is fairly easy most people w/ a head and cam swap are at anywhere from 410-440 at the wheels. 01-02 have slightly better heads but to get the goals you want the heads will be coming off anyways your best bet is to find the lowest mile motor you can find. On here or ls1tech they have tons of used heads and cams so parts are abundant and cheap

For example a 224/224 (cam only) will net you around 390 territory
ls1's will hand 450rwhp reliably, but you will be taking out the reliability factor once you add a 100 shot on top of that.

As for throttle bodies they are all cable so your good on that, and if you can only manage a mail order tune frost is the man (just search for him under members,also a th400 does not take much we have one guy running around locally just never asked him.

**Sarge** · 03-09-2009, 03:21 AM

I'd use a LS6 block for a few reasons....firstly to make sure you have got a LS6 block look on the back ( use a mirror) of the block on the drivers side by the transmission and you should see the number #12561168.....about 20% of the FBodies in 01 received an LS6 block.....and of course all the Vettes....the LS6 is GM's best block....has much better oiling capabilities, extra webbing around the cylinders for strength....there are cutouts that allow the air to flow from one cylinder pair to the other at high speeds to prevent too much pressure on the underside of the piston....LS6 blocks have a hole machined thru the main webs to improve bay-to-bay breathing......the hole cures the bay-to-bay oil vapor pumping issues.
As for your aftermarket question there are a ton of manufacturers/setups that will easily get you to your goal of 475HP. I use Patriot heads myself....but Dart and many others make good flowing heads for the LS6......yes get as much of the ECM/wiring harness etc. as you can from the donor to make life much easier.....For your TH400 our sponsor Summit can hook you up with the adpater you will need....
http://store.summitracing.com/partde...5&autoview=sku
I know I blew through this so hopefully others will join in...man this time change has screwed me up!

**qwkgto** · 03-09-2009, 04:23 AM

Dont even need an adapter the 400 turbo will bolt right up you will need a specific made converter,I have one it has the front for the ls motor and the rear slides into the 400 turbo.otherwise all GM transmissions rear wheel drive bolts together,might need to trim the ear near the top of trans above the starter.

**Sarge** · 03-09-2009, 04:38 AM

Yes....but it depends on his converter.....if it is the older style he will need the adapter....

**RCcola55** · 03-09-2009, 05:43 PM

Im really wanting to stay with the 5.7 block. My main goal in the engine is to build a reliable, cost effective motor, so using a stock bottom end is a key point to this. Since it will spend its life in a offroad rig, i would like to keep the power band between 1800-5500rpms, but not saying it wont see more then that, but with dual transfer cases and a 6.72 axle ratio, that window is optimal. I have read a bit on cam choices and would like to closely match the cam to the heads and intake I decide on in order to keep the engine reliable and get as much for my money as I can.

I have heard these motors can produce up to 600hp without too many internal mods. So a goal for reliablity of 475ish hp with occasion n2o should be with in that. I have seen package deals from trick flow and a few others that claim that kinda of power for a decent price, but if there is a more effective route for less then thats what I am looking for.

**00z28bubba** · 03-09-2009, 05:50 PM

Originally Posted by RCcola55

Im really wanting to stay with the 5.7 block. My main goal in the engine is to build a reliable, cost effective motor, so using a stock bottom end is a key point to this. Since it will spend its life in a offroad rig, i would like to keep the power band between 1800-5500rpms, but not saying it wont see more then that, but with dual transfer cases and a 6.72 axle ratio, that window is optimal. I have read a bit on cam choices and would like to closely match the cam to the heads and intake I decide on in order to keep the engine reliable and get as much for my money as I can.

I have heard these motors can produce up to 600hp without too many internal mods. So a goal for reliablity of 475ish hp with occasion n2o should be with in that. I have seen package deals from trick flow and a few others that claim that kinda of power for a decent price, but if there is a more effective route for less then thats what I am looking for.

ls6 is still a 5.7 and cost about as much as an ls1 crate motor wise. assuming crate motor being one of your options.