LM7 LS2 Cam Swap Questions
 

O.k. So i have been reading up on all sorts of stuff, here there and everywhere. A lot of the info makes sense, and some leaves me scratching my head.

Like this one, As the topic states LM7 LS2 swap.

I had not really considered any sort of performance enhancements for my LM7 swap into my 86 C-10. but after reading another build and swap thread as well as an article on cams, I have reconsidered the non-enhanced stance in favor of a LS2 cam swap. By all initial reports it is a simple cam swap that adds a little performance at a best bang for the buck el-cheapo price. But a few things just dont ad up for me. So here are the questions. please straighten out my wonky way of thinking here.


LM7 is a gen 3/III while the LS2 is a gen 4/IV. It is my understanding that the gen 3 is a single bolt timing gear cam while the gen 4 requires 3 bolts for the timing gear? and that the two are NOT compatible. so how do you install a 3 bolt cam into a one bolt engine?

The other half of this issue is that the gen 3 is a rear mounted cam sensor while the gen 4 is a front mounted sensor. obviously you cant install the cam backwards so how the heck does this work?

now assuming that i could indeed install a (at first glance) incompatible cam into my engine, do the valve springs and pushrods require changing? or is it a drop in item?

thanks in advance.

-Izzy

Re: LM7 LS2 Cam Swap Questions
 

My 2000 LQ4 6.0 is a 3-bolt cam. It's a genIII.

Re: LM7 LS2 Cam Swap Questions
 

You need the LS2 timing cover as well. GM part #12633906, moves the cam sensor to the timing cover. It read cam position off the cam gear, so you also need the corresponding cam gear. Part #12586481.

Re: LM7 LS2 Cam Swap Questions
 

This was covered not to long ago on this board.

You can run a 3 bolt cam in a GENIII, you just need to make sure you have the right cam sprocket for the motor.

In order to run a GENIV cam you have to get a GENIV front timing cover that has the cam sensor provision and jumper to the old plug at the back of the motor.

Springs are usually a good idea and pushrods are not a necessity.

A lot of good info on the thread below:
http://67-72chevytrucks.com/vboard/s...d.php?t=686875

Re: LM7 LS2 Cam Swap Questions
 

whoops i posted the link to the article above...nevermind :lol:

Re: LM7 LS2 Cam Swap Questions
 

if you ask 10 different engine builders and or hobbyist engine builders what cam choice... well you will get 10 different opinions. with that said, I like the ls2 cams in the 5.3 engine. gen3 engines use 3 bolt cams. the ls2 can be had in 3bolt or single bolt flavor. you need the 3bolt. you need the ls2 front timing gear, front timing cover with sensor, sensor harness, either build it or buy one. yes you should get the gmpp springs. pushrods are not necessary since it is still a 7.400 designed cam pushrod setup. most of all, have fun.

Re: LM7 LS2 Cam Swap Questions
 

Why not just get a drop-in cam shaft from someone like Brian Tooley Racing or Cam Motion? They each have a couple of different options designed specifically for the truck motors that work with stock push rods and the cheap LS6 springs. Yeah the LS2 cam is a decent option but they're still $150-250 for a used one depending on where you get it and with the extra money for the front timing cover, cam gear, extension harness, etc you're really not saving much...

Check these guys out:
http://www.briantooleyracing.com/btr...-camshaft.html
http://store.cammotion.com/ls-truck-camshafts

Re: LM7 LS2 Cam Swap Questions
 

I just built a l33 HO 5.3 engine with 243 heads, ls2 cam, etc etc. stout little engine and low buck. ls2 cam was a take out cam with less than 1hr dyno time on it. $100. on ebay. new gmpp ls2 springs $56. on ebay. new ls2 front timing cover with sensor $49. on ebay. new cloyes ls2 timing gear and chain $19 oriellys. and I made my own extension harness. I paid $800. for the l33 at a local boneyard and it came with the 243 heads. I also put arp rod bolts, main studs, and head bolts in it $385. and new GM gaskets and seals thru out $210. replaced the rod and main bearings clevite77 $85. low buck, ls1/ls6/ls2 killer. and will run on pump gas and stock tq convertor all day long. again, low buck.

Re: LM7 LS2 Cam Swap Questions
 

brian tooley cams, tsp cams, and others are quality cams and great companies to deal with. by no means am I saying otherwise. go to www.carcraft.com and read the 5.3 cam dyno article. they take a boneyard stock 5.3 and dyno it with a bunch of cams. the ls2 cam gave the best rounded out performance. good hp, good tq, and good driveability manners. iirc 210ish dur and 550 lift. not saying don't use the bigger cams just consider that if you go bigger you loose driveability and cost more $$$ when buying dual springs, hardened pushrods, or custom tq convertors, so on... in the carcraft article they tested the stock 5.3 and with the ls2 cam made 403fwhp. well if you take that up a notch and start with the l33 ho 5.3 with 243 heads and add an ls6 intake, add an 80mm throttle body, and some nice longtubes... your in the 425fwhp to 450fwhp territory really quick and not spending ls3 kinda money. have fun and happy motoring guys.

Re: LM7 LS2 Cam Swap Questions
 

You could have made it even more of a budget build by saving the 385 on the arp stuff you didn't need ;)

Re: LM7 LS2 Cam Swap Questions
 

thanks boosted... lol just insurance is all. but you are correct the l33 has hardened fastners from the factory. I wanted something other than the stretch to yield bolts.

Re: LM7 LS2 Cam Swap Questions
 

while all of this sounds great in the performance dept. I think for the time being that i will be putting this idea on the back burner for a little while. i am on a budget an this far exceeds the intended budget for my daily driver. not to mention that it is my daily driven truck and i do use it to tow the boat to the lake in the summer and tow other vehicles from time to time. I think the transmission needs a once over more than the engine needs a cam. when the budget allows this will likely be the first or second thing on the list.

One thing i have been thinking about is the extra 'crap' you need to do the swap, front covers and what not. it doesn't seem to far fetched to go this route, and i am still a total LS n00b so i could be wrong, but wouldn't it be worth while just to locate the LS1 cam with the same specs and throw it in there to eliminate all the extra garb? and i mean, for a little extra $$ you could go with a custom grind cam from comp cams for (i think) $300. if there was enough people interested you could do a group buy to get the price down to a reasonable price. just a thought.


-Izzy

Re: LM7 LS2 Cam Swap Questions
 

the ls1 cam is a mild cam. I likely would not go to the trouble of a cam swap if that's your cam choice. yes you cam buy a hotter comp cam with the rear sensor provision. and that is a good choice. keep in mind the hotter your go, the more driveability you loose. also the hotter you go, the more likely you need hardened pushrods, and dual springs, better retainers and locks, and then likely a better tq convertor choice. but im with you, I would likely give the trans a good looksee if it is at all questionable long before a power adder. have fun and happy motoring.

Re: LM7 LS2 Cam Swap Questions
 

My apologies, I misspoke, I was referring to the 2001 LS6 cam, NOT the LS1.

The 2001 LS6 cam has the SAME specs as a LS2 cam & has the Cam Sensor Reluctor.
204/211 .525 .525 116.5 LSA

Which I am assuming is a rear sensor and single bolt sprocket set up. GMPP had discontinued this item, which is why I was thinking custom grind of it came down to it.


Which ultimately if I could find this cam, it would be a quick and dirty install and go.

-Izzy

Re: LM7 LS2 Cam Swap Questions
 

ls6 is not a single bolt cam.

Re: LM7 LS2 Cam Swap Questions
 

Asked the same question a few weeks back.

http://67-72chevytrucks.com/vboard/s...d.php?t=686875

Mr. Boosted was very generous with his knowledge.

P. :D

Re: LM7 LS2 Cam Swap Questions
 

no need for the ls6 intake. the truck and tbss intakes flow just as good up to 6-6500rpm and make more torque due to the longer runners. if i could have fit a truck intake under my z28 hood, the ls6 would not be there.

hot rod magazine just did a huge test on like 15 different intakes. the truck intake makes some of the high dollar stuff look silly.

Re: LM7 LS2 Cam Swap Questions
 

If the $ is the issue. Just drop the LS engine in stock, still should be fun and much more power than a base 350. Just shift at 5500.

As said before, all the Truck gear is just fine as-is.

I currently run a LS2 on LM7, but because I like to shift a manual. If I went Auto, I would have kept the stock cam for a driver. Hopefully that made sense.

Re: LM7 LS2 Cam Swap Questions
 

the vehicle it was going in had hood clearance issues, ls6 intake was necessary.