6.0 lq4 chevy LS cam input needed
 

Okay some of you know I have a couple threads going... one on whats really needed to swap an LS engine and the other is my rebuild of my 21 scarab excel. I'm getting ready to bring home my new to me 6.0 engine. I'm looking into cam options for my boat. 250kelly has a nice cam going into his 5.3 ls. I'm wondering what LSA I should be looking at for my cam options. the one he installed has an lsa of 112 degrees. here is what I'll be having going on. 21 ft scarab weighs 3100 lbs roughly. I'll be running lightning headers and a custom mapped ecu running speed density program with O2 sensors. yes i'm keeping those as I have seen a few header spacers that have an O2 bung in them. I'm keeping the factory long runner LQ4 intake as everyone on the ls engine forums seems to agree this is the best intake for running under 6000 rpm. I will get bigger injectors if the cam requires it. factory compression on this engine is 9.5:1. any help is greatly appreciated. I have a feeling I may have to end up calling comp cams or someone along that line. :/

What power are you looking to make? LSA is really irrelevant unless the rest of the cam is considered. valve events are what counts, Believe it or not an ls9 cam on 6.0l is about 450 hp -11.5 degrees overlap idles like stock (because it is for a ls9) and dirt cheap, under $100. The lobes are easy on springs, if you have a gen 3 6.0l then you need single bolt ls2 cam gear, I would at least do comp 918 or equivalent springs and hardened push rods. Also the Fast truck manifold is worth some power.

I want something with a noticible idle but still maintain docking manors. its a 2002 engine, but I plan on a new timing set. So I can get a different gear set if needed if going from the single bolt to the three bolt cam. the fast intakes are 800-900 bucks for not a really big gain from what I understand. I'd love to be pushing 450 hp, the more the better in my book...lol I'm not looking to set any speed records just out having fun on a local lake. I'm just worried about reversion and dont want to drown a motor due to poor cam choice.

Ditch your cylinder heads,get a set of ls3 cylinder heads,,go with the gm hot cam and ls7 springs and go boating.the hot cam on a ls3 engine makes 480 hp and 475 ft lbs tq.. here how it sounds http://www.bing.com/videos/search?q=gm+ls+hot+cam&FORM=HDRSC3#view=detail&mid=C4EA592B7B9B4E0E4F97C4EA592B7B9B4E0E4F97

damn that sounds nice.... my biggest fear is hydro lock. my 350 that was in the boat had a cracked head and bent #8 rod. so this year I'm stuffing a 6.0 lq4 into the boat but I dont want a stock cam. I love the sound of that vette. I've been looking at intakes all night. I love the holley high rise or the edelbrock xt. If anyone has looked at my build thread i have on my boat you will see why a plane jane stock looking intake will not look the part on what I have going on...lol sadly I will have to make my alpha 1 survive a season with the new motor before I can even think of a bravo swap...

the 317 heads on that engine are fine, we made over 1000hp with them with boost, that hot cam sounds great but may not do well in your boat, keeping the 02 totally dry may be a issue, and some cams will make that even worse, you won't need much cam to make good power

comp XR281HR if you want lope this cam is great I used to have this cam in a car. this with a fast intake is about 490hp crank. probably about 460-475 without. Ls3 (stock head) cams will need more split I like 6-10 degrees. closer to 5 for ones with a port job. 317s are ok heads NA not as good as ls6/243 for NA stuff. CNC'd ls3 heads are 1200 bucks for a set Plus a stock ls3 intake is damn good and cheap. total of $1500 more and make 40-50 more hp. if you are on tight budget run a stock truck intake and that xr281hr cam. Otherwise CNC ls3 heads work well. TSP 229/236 cam, ported stock ls3 manifold, should be about 550hp

I sold a guy a Black hawk drive on OSO he put it on a 22 scarab I Know was planning on working the props, and moving some weight around to get it to lift the bow and expected a nice gain after words, That might be something else worth looking into.

the hot cam will a also be fine if your are running headers..just make sure the o2 sensor is on top between 10 and 2 oclock...Btw the LSA for the hot cam is 112* advance the cam 2 * and you will be fine and that will mover your torque band down a few hundred rpm so your redlind will be around 5500 rpm..i spin mine to 6200 all day long..

just to add,,if you decide to go with a ls3 cylinder head the heads really like a 115* lsa camshaft..so choose wisely..

I think I seen the post on the blackhawk outdrive. It looked like she'd move. So after reading all night I think ill be running either the stock lq4 intake or maybe the fast if the budget allows. I need to keep the compression about where it is as they don't sell anything above 91 octane around here. I know the o2 may be a challenge but it will run far more efficiently with them than without. Are new lifters needed when swapping the cam? Arnt these roller lifters from the factory?

as long as their is no ware marks or pitting on the wheel of the lifters or cam you can reuse the lifters..

You might want to consider switching over to a carb set up, so you don't have to run a fuel pump, and return lines from the tank..and carbs are easy to tune and can make power..sorry I cant help you on a cam..just throwing my .02 cents out there on an intake..

This got got it working fine with Oem computer I believe http://www.classicglastron.com/phpbb...hp?f=34&t=5852 or you could go with a holey and let it tune it self

I forget what year it was but they switched to a returnless system. I have considered the carb system running the msd brain box.

That glasstron is sweet. I love his cooling system but I'd still need a pump since he has a jet boat. I didn't know pcm made an exhaust like that even set up for o2 sensors. Not as trick looking as headers but still a nice looking system.

if you run a 97 vette fuel filter it has fuel pressure regulator built in

yeah I have heard about the vette mod on several ls swap forum projects over on the ls forums. seem pretty sweet. I found a set of rearward headers for about a grand. I guess they are big over on the jet boat side of things. they make a set of wet headers for through transom applications. anyone know anything about them?

Yeah those are water injected not water jacketed, you probably don't want to run those under a hatch. these ones right? http://www.rewarderheaders.com/pages...%20header.html

Damn didn't see that... found them on cp performance. Thought they would work.... oh well. Lightning headers will work. Yeah not a big fan of bon fires out on my boat..

call lightening,,jen will make you a set...also cmi makes a set to order..

http://www.cpperformance.com/p-16837...t-headers.aspx

I cant find anything on the cmi ones I know I have seen them but can't find them now. I mainly want to see if they can put an O2 bung in them for me to save some hastle.

If your going to run dry pipes a 112lsa cam will sound great and make good power in that boat. Particularity in the 220 duration up. I would check out the TBSS intake. It makes more power across the board vs the stock truck intake, is a relatively easy swap for the money. Stock 317 heads will work fine, unless you have the money to get a set of ls3 heads( will have to run a diff intake as these are not cathedral port), or if you want a little more compression out of it find a set of 799 or 243 heads, use the truck or TBSS intake. Slap some marine 44 lb injectors out of a 496 in it, have it tuned and have a reliable set up.

John jr

Im planning on wet exhaust. I've heard good things about the tbss intake. So 44lbs injectors out of the 496 will work? Cool do I need to change the plug ends on my harness?

Anyone one know of a good tuner to send my ecu out to for reprogramming?

just read a head test between the 317 and LS3 below 4000 the 317's worked better, above that the LS3's did the job...I still think you will have a issue with the 02's living...

here is what the cmi's look like..
http://i35.photobucket.com/albums/d1...ps28701351.jpg

http://i35.photobucket.com/albums/d1...ps6391ead2.jpg

http://i35.photobucket.com/albums/d1...psd88118b3.jpg
pics were uploaded from the late scot van from donzi . net

I have never done it, just throwing out an idea. Wouldn't it be fairly easy to machine an aluminium spacer between the head and the exhaust to mount the o2 sensor?

The spacer idea is probably the way I will need to go. The plus side is if I loose an O2 sensor then I know I'm about to loose an engine... kinda the canary in the coal mine. I love those cmi headers.... damn good looking

he cut in half his riser spacers and welded in O2 bungs. need to go wide band also for O2's, seems narrow band could not adjust properly. would think tunercat or efi-live would be good investment if going factory efi(automotive)

I priced out a set of 8.1l marine injectors... ouch...lol I'll gladly do it if the budget allows. I talked to Justin at blackbear about tuning my ecu. I've heard his name around many boards so I figure what the heck why not. I've got to talk to my engine builder and see if he has a cam suggestion or not. More likely than not I'll be calling comp for a custom grind cam. I'm hoping just a rering for the block and new bearings. the bores look good to the eye but we shall see. most of my money is going to be in the cam and valve train... since im only wanting 450+ hp I'm pretty sure the stock bottom end will hold just fine, unless my engine guy says differently...I've got six weeks before I can throw big money at this beast... lol

So I talked to comp cams.. and here is what i got.. After looking over your combination, I would suggest that I custom grind a cam for you. Most of my book cams are set up more for vehicle use with focus on upper end power, which you will not be using or needing. I would suggest grinding you a 220/226 duration @ .050, .564/.570 lift using stock 1.7 rockers, on a 111 LSA. This should keep the power under 6K RPM, and give you a stout, flat torque curve as well.

Like EZ said, stick with your heads, and the intake works great too, just a little ugly. Call Bob Madara at Marine Kinetics for the cam, he has done several LS cams for me and all have been excellent. That Comp cam will leave a lot on the table.. Holley HP EFI is plug and play into all your factory sensors and coil packs, the only other wires to hook up are power and ground, and it will self tune. About $1350 for the LS. I have a few sets of new take-off alumminum exhaust manifolds if you still need some. $800 They look like this

I just emailed Bob Madara so I'll see what he has to offer as far as a cam goes. I've seen his name all over this forum. Its crazy I didn't know he was in upstate NY. hell I used to live about 40 min from his shop. I just set up getting the engine built yesterday, so now I just need to get the wiring all laid out and I can drop of the motor to get her freshed up. Haxbyspeed what are you guys doing for coil relocation? I have the standard lq4 coils and I have to obviously relocate these so my exhaust will clear them.

Just spoke with Bob Madara... just like everyone else has said, super nice guy easy to talk to. I'm excited to see what he comes up with for me.

Huge shout out to bob madara all I can say is you can tell he has a passion for this industry. just got the specs from him today and I'm having him set me up with a spring package as well. All I can say is WOW... I'm excited to get this thing together and back in the boat..lol I need to live some place warm so i can make some test runs over the winter...lol anyone else ever what to get the best information on an ls set up the two guys to hit up are haxbyspeed and bob madara. Now I can hopefully get my ecu sent out to black bear and really turn up the heat on this build.