LetsGetThisDone

iTrader: (1)

Aluminum heads almost always need surfaced. It's easy and not expensive to have done, so it's worth getting done every time.


To flatten it with heat, you would need to apply localized heat to it, and it would take some experience in doing that, and would likely be expensive.

heel2toe

iTrader: (41)

OK good to know. Wasnt sure if you were saying that from a surface prep perspective or rather that they are almost always warped. I'd rather not surface it if it didn't need it but that is more out of paranoia that eventually itll make the head an expensive paperweight after multiple times being machined. I could of sworn the service limit between the block and head is only like .008" but that number may be way off and I worry about things that I shouldn't.

LetsGetThisDone

iTrader: (1)

4b11slayer, if you really are in the 11.8-12.3 range as that thread suggest, you should really be targeting low 11's on the stock to keep the pistons happy. And 12.3 is too lean. Should be 11.9-12.0 at the leanest.

LetsGetThisDone

iTrader: (1)

Their is a service limit, but that's more to keep timing correct. You can use a thicker gasket to make up for taking more off.

heel2toe

iTrader: (41)

Didn't even think about timing; was more concerned about smashing valves.

As for AFR's yeah Id agree 12.3 is a lil too hot for my liking. I assume this is on corn at the very least. I dont think 12.0 during spoolup is bad probably could get away even leaner slightly, but up top 11.8-12.0 seems to work well.

Im not a tooner but I do play one on TV.

LetsGetThisDone

iTrader: (1)

Running richer keeps things alive when doing those long freeway pulls in mexico.

heel2toe

iTrader: (41)

Lol @ freeway pulls in "mexico"

Same thing with timing which can be notoriously difficult to gauge how much to throw at it if you don't know what you're doing. Long freeway pulls or track duty means high EGTs.

I love wrenching and tuning is very interesting to me but boy am I glad my BFF(lol!) knows what he's doing bc I certainly dont!

4b11slayer

I am 11.8-12.0 afr now after going speed density.
So ill get the head resurfaced and onces its all back together ill go out and add some more fuel uptop to keep her cool.

Thanks for the input guys

heel2toe

iTrader: (41)

Notice the mention of the lubricant. Withought that the torque should probably be more

Pal215

iTrader: (12)

Just in case someone sees this thread in the future:

Abacus

iTrader: (9)

Sorry to hear about your headgasket issue. Have the head checked while its apart.


Lean is mean to a point. The same goes for advanced timing. They don't just keep making more.


FWIW, I ran my stock engine at 11.2 AFR and 11.8 AFR back to back (2 runs each) and it made the same power on the dyno. Alot of the local Evo tuners also target the lower part of the 11's on the stock engine. Its better to have it on the richer side of things to cool the cylinder but you are also looking at an AVERAGE of the whats in the exhaust. If your rail or more importantly injectors aren't flowing close to each other then one cylinder could be leaner then the others.

Ethanol will be harder to light off when richer so a tight plug gap (.018-.020) and a strong ignition system are a good idea.


Now, my built engine runs 11.5-11.8 and makes a little more power /runs cleaner but its got compression/headwork/magic sauce .

Its nice to use a chassis dyno to really dial a car in . Its relatively cheap for results it can give you.

4b11slayer

The car is running 18 * on the big end. Around 4-5 around peak torque.

And afr of 11.8-12.0. Once i get it running ill go do some adjusting and bring it in closer to 11.5.

Also the car is on e85.

You think resurfacing the head will force me to lower timing?

LetsGetThisDone

iTrader: (1)

Just use a thicker head gasket, like I already said....

Also, your timing is pushing it.

Abacus

iTrader: (9)

I just think its a good idea to see what timing and fuel net you.

Less is more in the end.

4b11slayer

I already ordered a oem head gasket. Ive been running same timing for maybe 2years now.

Less is more can you please shine some light. I dont understand