LM7 vs L33 for S14

[1slowsilvia]

So I am gearing up for a LSX swap and looking at the LM7 or maybe the L33. Reason being is these motors are super cheap make good numbers and are a dime a dozen. Now heres my pickle I have looked that LM7 and read many things on it being iron block with aluminum head so this motor should be stronger and happy to take boost but its con is weight with the iron block it will weigh about 65 - 70lbs more than the L33 which is all aluminium.

The L33 on the other hand had a half point higher compression so should produce better numbers and lighter by 65 - 70 lbs. My car will be a daily / sometimes track car for shits and gigs maybe a little drifting here and there at tracks possibly take it down to sebring for a few hot laps.

What do you guys think LM7 or L33?

Right now I'm leaning LM7 because I have a full swap minus the trans I can get for 400$

[PIN GIO 2]

go for l33 no discussing

[Frank_Jaeger]

I'd get the LM7. Relocate the battery and put the engine as far back as you can. No big deal.

[EndlessSummers]

If you have the lm7 do that. And what trans are you getting for $400?

[blueshark123]

If you have the lm7 do that. And what trans are you getting for $400?

he is saying 400 no trans. If u had to choose between those 2 i would go l33. If ur set on going turbo lm7 but if ur doing that mine aswell get a lq4 at that point but for 400 fuck it thats cheap and turbo it.

[ka-t]

why are you worried about 65-70 lbs. thats nothing - relocate the battery to the back the you keep the balance

[Michael E]

L33 all the way

[2muchboost]

L33 if you can and its not a huge price difference. The aluminum blocks have taken an ass kicking and still done well.

Check out S13LSx on the LS forums, he had an 06 L33 boosted on E85 and ran an 8.76 before passing away. The aluminums have been pushed past the 700rwhp mark numerous times.

Vettewreck started a thread discussing both blocks being pushed for high boost...check it out.

I personally took my LM7 in pristine condition for significantly less than I found the aluminum blocks so I will be boosting this biatch until it pops. The iron blocks have also seen some big numbers and boost.

[tauntdevil]

LM7 and L33 are not very expensive. Maybe it depends where you are because in Arizona, you can pick them up for about $450ish all day without a trans or ecu. Often with harness.
Buy either one and build the hell out of it. The expensive part isnt the engine but the work done to install the engine and everything you want.

[2muchboost]

Here in NY i wasnt having much luck finding aluminum motor for cheaper than what I picked up my LM7 for.

Depending on your goal you may not need to build it up. Many over at the other forums have literally taken JY motors and slapped cam, springs, and boost and been very successful....Especially on the newer ones with stronger rod design (I believe 05+ but dont quote me). The earlier generation motors were supposed to have "weaker" rods but again some research will provide some insight.

In regards to the expense of the setup install, that really will depend on which route you go. A lot of guys have swapped them out for a lot less than the "average cost of an LSx" build if your a DIY-er. Again depends on many factors including your power goal, trans choice, how much work you do, how much work you dont do etc. If you are going T56 that will likely be one of your biggest expenses regarding the swap.

[blessedhellrider]

iron block will hold more abuse !!!

[2muchboost]

That may be the case but with OEM sleeves the L33 (especially newer gen) can take an ass whooping, more so than the OPs goal most likely. Bone stock L33 with an SC400 and a powerglide in a 2900 lbs car ran 9.3 1/4 @ 15PSI on E85.

Theres a Vette running a rear mount setup with an L33 making over 700rwhp/700 ft. lbs with Pump and Meth at 16 psi.

Another example, L33 + head studs + Valvetrain + turbo & E85 on powerglide making over 800rwhp on 25+PSI

Moral is, that the L33 is likely more than capable to what the OP will be aiming for. The Iron block may ultimately be stronger but that point is likely moot at the power goals our cars need to be successful in 1/4 and other types of motorsports. If you can save the weight and they are about the same price then why not go with an L33 (05+) with stronger rod design? My 2 cents