jridenour31

will the ms3 work in an lm7? i've been looking at the kit from TSP. i've done a lot of searches and haven't found what i'm looking for. this will be going in a 94 camaro, mostly drag, some street, not my daily. is there a better choice for a drag car? what else would be needed for a cam swap for this engine? i will be using ls6 intake, longtubes, and a big stall.

jridenour31

any lm7 cam swap info? what kind of power am i looking at?

lastcall190

iTrader: (36)

Do you by any chance mean LS7? Not LM7?

-J

ss.slp.ls1

iTrader: (36)

Probably not, LM7 is the 5.3 vortec motor.

As for the cam, I don't see why not. It's an LS engine, same stroke with a smaller bore, most everything is interchangeable.

lastcall190

iTrader: (36)

Learn something new everyday... thanks for pointing that out.

-J

Eurospec2

iTrader: (2)

In my opinion, that cam would be way to big for the 5.3, but hey, its worth a shot

ss.slp.ls1

iTrader: (36)

I was assuming that accompanying the cam would be new springs, pushrods, etc.

GreenBlood

iTrader: (6)

even then, i agree that it might be too big...a lot of the trucks on performancetrucks.net and the old GMfullsize.com don't run big cams in the 5.3...They usually recommend durations between 212-218...Many run a 220/220 with a 224/224 being the biggest. I think I saw one guy running a 228 cam, but that was consided really big...I know this isn't a truck, but it is the motor...

ss.slp.ls1

iTrader: (36)

I like the TR 224 anyway, maybe give that a try.

ss.slp.ls1

iTrader: (36)

Put it this way,
Swapping in a LS6 cam will net almost 40 hp with no other mods
Swap in a 224/224 cam and some 243's (LS6 heads) and that number will be much higher. You can find used LS6 heads for $400-500.

5.3LJimmy

iTrader: (10)

I wouldn't put the MS3 or any large cam in a 5.3. You will loose all bottom end torque unless you bring the static compression up really high. Bringing the compression up to an acceptable level would require the use of flat top or dome pistons with valve reliefs, milling the heads at least 0.030, and an 0.040 gasket. Since no one stocks aftermarket pistons for the 3.779 bore it's alot easier to stick with a cam with less than 230 duration.

jridenour31

losing low end torque isn't really a concern, it's pretty much a lightweight race car that will have a 4000+ stall and 4.10's so it will be into the powerband very quickly. the heads will be milled, how much i'm not sure yet. hopefully shift points will be 6500-6700 rpm.

i know the 243's flow better than the 5.3's, but i'm assuming that putting them on a 5.3 would cause intake valve shrouding due to the much larger valve. i am considering just using the ls6 cam for now and eventually get a custom cam when i get the heads ported.

i'm just trying to figure out the best cam to use. i figured the ms3 was too big. i'm used to mustangs having major ptv issues with most cams and want to make sure i don't go to big.

the truck comparison doesn't really apply, sure it's the same engine but there is a 2000 pound difference, the truck needs a lot more low end than my car.

sorry for the long post, just trying to get the best info possible

ss.slp.ls1

iTrader: (36)

What's your budget?

Used LS6 cam ~$200
Used LS6 heads ~$400-500
Used LS6 intake ~$350

So for about a grand, you'd have a pretty nice set up.

s346k

iTrader: (4)

that engine is essentially an sbc 327cid engine with much better internals, etc. i wouldn't be afraid of the ms3. i think because of the smaller cubes it would easily push the powerband up into the 6,500-7,200 rpm range. if it will physically fit in the engine with the heads, etc you want - go for it. i would also opt for a larger stall, maybe 4400+. as a 4k stall would be about right for a 346 cid engine, but using a smaller engine will merit using a larger stall. you can ALWAYS switch to a larger stall to compensate for the large cam. DO IT.

jridenour31

pretty much exactly what i was thinking, probably using the yank pt4600 or ut4800

FBJR

I assume the MS cam is a manufacturer, but who? Only been on the forum for a few weeks now and doing a 5.3 conversion.

What about the GM hot cam?

Juiced

iTrader: (2)

texas speed, magic stick 3

FBJR

Thankyou

ss.slp.ls1

iTrader: (36)

I would run a TR224 or an F13 before I threw in a MS3.

jridenour31

the 224 is a very mild cam and i'm sure it works well in mild street driven setups, but i don't care about streetability, i just want it to go down the track fast. the f13 has much better specs and is actually a possibility for me. has anyone swapped a fairly large cam into a 5.3? i've heard that 241's and 5.3 heads flow similarly and if that's true the ms3 shouldn't be too much for the heads, the only issue would be that it might peak too high which is what i'm mostly concerned about. where does the ms3 peak in an ls1? where would it peak in an lm7?