cobalt_sport08

iTrader: (1)

Everyone says my internals are **** and I shouldn't boost past 5ish. I got my hands on another head so time to start the rest.

Going to get it ported not sure what though(exhaust I want to be 1.75) so I'm asking what the intake should be? any input is awesome

Valves? suggestions??
ZZP TTR OTTP what does 1mm over mean?

valve spring kit: what is stock #?
Is 82# to much for stock cams? I was recommended to go with 78# but zzp only sells Supertech 75/76 and 92#. also OTTP and TTR sell

next I was wanting to install pistons and rods.
from ZZP i can keep the compression at 10.4:1 or should I lower it too 9.0:1
for the rods I was looking at the 4340's
OTTP and TTR sell as well

SO looking for a push here who has had experience with what and what is recommended for a supercharged build. I want to pulley down to a 2.9

Thanks

lsjion

I would suggest 75-78 for springs. Especially on stock valve train
As for valves. The 1mm OS means the seat would be cut larger, and the valve is 1mm larger in diameter. Increasing flow. Once the seats are cut, I blend the bowl from the overhang thT happens when cutting seats.
If you're staying SC keep the compression where it's at. Blower cars love it

Spawne32

iTrader: (1)

1mm over on the valves means that the face of the valve is 1mm larger then stock, the valve seat on the head would have to be recut for the new valve. #82 is a bit much for stock cams, always er on the side of being lighter then heavier, stresses the valve train less. Given that its a street car thats going to be daily driven, this is important to consider. The rods and pistons I dont know much about for these car's as far as availability, but go for a low expansion alloy for the pistons if possible. 2.9 build doesnt really require forged pistons, the rods are the weak points on the 08+ LE5's thats all, if you could source a used set of OEM forged rods from a 06-07 motor they would work fine.

2006-2007: 12596088 A 2.4-B/P (LE5), (1ST DES) ROD, CONN (FORGED STEEL W/ROUNDED EDGES ON CAP AND MFG TRIM MARK AROUND OUTER PERIMETER) (FOR 2ND DES SEE 12611360)

2008+ 12598216 A 2.4-B/P (LE5), (2ND DES) ROD, CONN (POWDER METAL W/SMOOTH SURFACE CAP AND SINGLE RIDGE ACROSS CAP, W/O MFG TRIM MARK AROUND OUTER PERIMETER) (FOR 1ST DES SEE 12596088)

cobalt_sport08

iTrader: (1)

OK thanks guys i'll probably be going with 76# springs since that seems to be the easiest to find then get upgraded valves but stock size.

Ill begin looking for 06-07 cobalts. now is this any model or do i need to match another 2.4?

and are 4340 forged or just a strong metal over stock? ZZP/OTTP and TTR(K1) sell 4340

are these part numbers for the rods?


side note I was going to go with 82# cause zzp said it was recommended when boosting past 10psi

Spawne32

iTrader: (1)

Yes, those are the part #'s for the rods, they would have to be exactly from a 2.4 as the length of the rod would be critical to using them in your 2.4 block. The factory forged rods are made on the same casting process as the LSJ forged rods so you can expect them to have similar horsepower limits. 4340 pistons are forged, just a different type of allow that makes them low expansion, which gives less headaches when building your block, as you wont have to worry so much about piston slap and piston to wall clearance from piston expansion. Supertech most commonly makes these types of pistons and usually they include P2W specs with the pistons.

cobalt_sport08

iTrader: (1)

Ok thanks! With that being said about the 4340s, wouldnt they be a better upgrade just in general?

And will the LNF valves from ZZP work in my LE5?

Spawne32

iTrader: (1)

Are you talking about the rods or the pistons. The rods that ZZP sells are total overkill for anything under 400hp, given what the stock rods can handle. The oem pistons on the other hand are heat treated cast, which are typically also good to around 400hp but upgrading the pistons doesnt hurt at all. All depends on what your power goals are.

cobalt_sport08

iTrader: (1)

rods since that's the weak point on my 08 and i doubt my car will ever break 300hp

and ZZP contacted me back and the LNF valves will work.

Spawne32

iTrader: (1)

Yes the LNF heads are virtually the same as a LE5 with the exception of the HPFP modifications and lack of port fuel injection. That's why im running the LNF exhaust cam (slightly larger then the LE5). Honestly you dont need that crazy of a rod if you dont plan on breaking 300hp, and in reality, you dont need anything other then factory pistons as well. the factory forged LE5 rods are plenty for that power level.

nhanson

iTrader: (1)

Im shooting for 400! Hopefully it stays together

andrewcarr1993

iTrader: (5)

I'm puttin in a 06 2.4 and shooting for close to that.

cobalt_sport08

iTrader: (1)

HPFP?? And ive always heard ppl say my internals are ****.. Now they'll handle power?? Ha it's a high compression motor plus boost sooo heat I'm sure might potentially be an issue and I DO NOT baby my car. I have dual pass iat2s now are about 80 summer will be 100+. I'm over 100k miles and what this b*tch to carry on

cobalt_sport08

iTrader: (1)

And while I'm at it what cams will fit my le5?? Zzp stopped selling the 2.4 cams on the web

Spawne32

iTrader: (1)

HPFP is high pressure fuel pump, thats what the turbo cobalts have. The LNF heads are in essence the same as a LE5 but they are provisioned a little differently, and yes they handle power just fine, and they are no means "high compression". They are 10.4:1 from the factory, its a moderate compression level but not high by any means. The disadvantage with the 08+ LE5's is that the rods are not forged, thus limiting their power level to 300 and under, and even then the risk are greater.

Unfortunately the only alternative right now for bigger cams is you can run an LNF (turbo cobalt) exhaust cam, which increases the lift from .395 to .405 and changes the LSA from 130 to 127.5. There are no other aftermarket LE5 cams to speak of that compare to ZZP's.

cobalt_sport08

iTrader: (1)

I'll have to start looking for some forged used ones just hate that they would be used. Or I could just buy new Molnar for 385 from OTTP and can you dumb down all that can talk.. I'm just now getting into internals :/

Does the increase lift mean more flow exiting the head/exhaust?

Spawne32

iTrader: (1)

Well I don't want to turn this into a cam learning session so Ill simplify it as best as I can. Lift is how far down the cam pushes the valve, and duration is how long the valve stays open. LSA (lobe seperation angle) is the angle the lobes are positioned opposite of each other in crank degrees, and centerline is the degree in which the lobe peak lift is centered on the cam's full 360* rotation. More lift and duration = more power but there is more to it then just that alone, opening and closing events of the valve have to be timed to make power.

Try mongorat for used 2.4 rods, hes a seller in the for sale section just look for his username. Absolutely nothing wrong with used rods, that would not be a concern at all for me. With your power goals molnar rods are just flat out overkill for 300hp, but if you really insist, it wont hurt anything, just make sure you get the rotating assembly balanced at your local machine shop.

cobalt_sport08

iTrader: (1)

ok gotcha! thanks

I'm going to start looking for some stuff then


Next would it be necessary to pull the engine or can I just drop the bottom end?

Spawne32

iTrader: (1)

Yes, if your going to start swapping internal components, the engine has to be pulled, if your doing rods, your looking at bearings, piston rings, and a hone on the bottom end if you want to do it correctly and have it last.

cobalt_sport08

iTrader: (1)

so not just a simple unbolt and replace -__-


you said you were running an LNF exhaust cam what about the intake is it stock?

thanks

Spawne32

iTrader: (1)

Yes, the LNF intake cam is not compatible with the LE5, the high pressure fuel pump on the LNF is driven off of a lobe on the intake cam. I have a PDF i can email you with specs of all the ecotec cams available and their interchanges, but suffice it to say, LNF exhaust to LE5 exhaust is the only compatible swap.

cobalt_sport08

iTrader: (1)

buying one tomorrow out of an LDK LDK is basically a LNF right?? its what ive been reading..

Spawne32

iTrader: (1)

No idea if the cam specs are the same.

cobalt_sport08

iTrader: (1)

I've never felt with zzp this much but people have saidbthe service sucks
.. So far they've replied in under an hr each time I ask a question.

They said cams were the same.

Spawne32

iTrader: (1)

It's hit or miss, depends on what kinda question your asking or if your complaining about a product. lol

cobalt_sport08

iTrader: (1)

I've begun reading about valve float and I don't think I fully understand it. I don't plan on doing any cam work so rev limit will be the same but since I'm uping the boost (2.9 pulley so 10ish psi??) and porting the intake and exhaust on the head.

Should I be worried about that? Thanks