ZX636RIDER03

So I just picked up an engine yesterday and after stripping it down, I realized that it was out of a caprice which had cast iron heads. Luckily, it is a 5.7 and not a baby lt1 after validating the bore size.

I heard that the cast irons flow better but they are much heavier. Is there any benefit to using these over my aluminum heads?

Injuneer

The aluminum heads, coupled with the reverse flow cooling system (which both have) allow more aggressive ignition timing, and take advantage of the higher compression ratio. Whether that offsets the cast iron heads better flow is debatable. The cam in the SS LT1 also makes a bit more torque at lower RPM, to get the mass of the B-Bodies moving.

MeanTA

There is no beniffet running cast iron. Cast iron heads flow is no better then aluminum. And don't respond to porting as well as the aluminum. The aluminum heads are a much better head for performance use.

shoebox

The iron heads also do not have screw-in studs.

Injuneer

It's documented through flow tests published online that the LT1 cast iron heads flow better than the LT1 aluminum heads, stock vs. stock. You're the first person in 10 years that has challenged that fact.

MeanTA

Sorry but that extra 10-18cfm(depending on whos testing). With a heavy iron head. That holds heat at a greater level. Is not a better head. If it is..... 1,000's upon 1,000's of performance engine builders are wrong.

Sorry but a couple cfm isn't a advantage on any level

ZX636RIDER03

Well didnt mean to stir things up, but thanks everyone for their input. I will definitely be running my aluminum heads once I get the bottom end back together with the components that im looking for. I'm debating whether or not to stick with the stock rods and pistons or upgrade them when building it back up. I would like the flexibilty to bolt on a super charger down the road.

Thanks,

Tom

MeanTA

No issues. He is a respected member of the LT1 circle. I see him on my other forum. Were just run in a different race circle. lol.... Thank he just miss understood what i was saying...

What is the ultimate goal for this engine?

96m6lt1

The steel head does flow better than the aluminum head however the weight difference makes the performance gains negligable.....


Sent from my LG-P999 using Tapatalk 2

Injuneer

If you read what I said carefully, you would see that I did not say the cast iron head was better, or recommend their use. I confirmed the OP's statement that the LT1 cast iron head flowed more, but noted that whether that was enough to offset the aluminum heads' compression and ignition advance capabilities, or specifically vice-verse, was debatable.

With regard to the head "holding heat at a greater level", the internal combustion engine is a thermal conversion device. The more heat it holds in the combustion chamber, the more power it makes. But again, if that extra heat contributes to hot spots that promote detonation, there is an offsetting consideration. Take some time to review the theory behind Evans Coolant, and you will understand that his goal is to retain as much heat in the combustion chamber as possible, hence the very high coolant temperature. But the characteristics of the Evans propylene glycol coolant resist nucleate boiling and the resulting hot spots on the surfaces of the combustion chamber that cause detonation.

MeanTA

I understand the theory. I have a Mechanical Engineer degree. And understand what involved in combustion operation. And heat is needed to promote a efficient burn. But to much thermal heat will cause indentation and a diesel effect due to extreme temperature igniting the gases(extreme circumstance) I was simply saying the iron head is not the best choice. No reason to pick at it. lol

Injuneer

That would be "detonation"..... and I already addressed that issue. And detonation is the result of highly combustible "end gasses" formed during the initial combustion event, causing a second flame front to ignite, remote from the first. When those two flame fronts meet, the resulting vibration and pressure surge damages part. You appear to be referencing auto-ignition, which is a different process.

If you want to turn this into a "my degree is bigger than your degree" contest.... you are wasting your time. I don't play that game. Is that what you came here for?

MeanTA

Jesus Christ man..... What is your issue? Sorry i did not use the spell check on my phone, or lay every definition out in a uniform manner. I did not come here to start crap you are doing that all on your own. I am was trying to help the guy out by responding to his post. Your the one talking to me like im beneath you.

I am here to help and. And lend a hand. Just like i do NICELY on ltxtech... Im not the one playing my stick is bigger then yours. Your doing that all on your own. You are the one turning this into a pissing match.

Step back clear yourself. Either find someone to give you a hug, knit a sweater, drink a beer. What ever it is you do. Come back with a fresh reset. And answer OP questions. This is the last time im wasting my time with you on this stupid conversation.

ZX636RIDER03

I use this engine primarily for High Performance Driving Events or track days. Recently, I snapped a connecting rod mid beam and destroyed my previous engine. I heard that over revving the engine in combination with hardened push rods could bend valves or punch a hole in a piston. There were quite a bit of lacerations in the pistons when I inspected them.

My last setup made roughly 320/332 rwhp/tq. Since I have the opportunity to build up another engine, I would like to add more durable components this time around. In the past I wanted to add a supercharger, but knew that they hypereutectic pistons wouldn't last long, but am not sure about the rods or crank. I heard the crank can handle up to 750hp so im assuming that would be good, but I would want to splay my mains from what im finding.

Right now im stuck on what rods and pistons to go with. I was looking on ltxtech under the FI section and they have a sticky that lays out all the components that those guys are running. So far it looks like SRP is a pretty popular piston for FI setups.

So basically im hoping to run this engine NA first then adding FI down the road.

Thanks,

MeanTA

The stock crank is pretty stout. I would trust it to around 15 pounds.

SRP pistons are a 4032 piston and are ok for low boost >12. And if you don't put it in a lean condition. I personally would suggest a 2618 piston. They can handle higher boost levels. And more forgiving in lean condition(not that you ever want that lol).

Rods you will want a H beam(scat, eagle) if you are on a budged. Otherwise go with a billet I beam like Oliver, Howards ect. Its comes down to whatever you like.

And splay your mains. Its necessary under boost ect. Plus its good insurance. I run Howard's splayed mains in my engines.

If you plan to boost it. And will be boosting the snot out of it. Set the rings under boost