Aluminum Heads

[elwaupo]

I have a 69 Camaro the I'm converting to efi. I'm installing an Edelbrock Pro-Flo and I have headers so I might as well install aluminum heads but which ones would work best with my engine? I have a 350 that runs better then stock with a Crane cam, any suggestions?

[GregWeld]

To guide you with a choice like this -- there needs to be MUCH more technical information about the motor. You need to know the piston static compression or how much it's in the hole... you'd need the cam specs -- lift etc - because this is critical info to match the FLOW RATE of the heads to the valve lift etc of cam... and the chamber size of the head to the compression ratio of the pistons. Without that info -- you get it wrong and buy too large of a head and have a lazy motor... with no bottom end. Too small and raise the compression too much and you have a motor that has pre-ignition and you knock a piston out.

If it's not a daily driver --- and you don't have the written specs on the parts you have --- you can pull the heads and intake off and measure how much the piston sits in the hole --- and get an idea for the shape of the top (flat top - or domed etc and the fly cut for the valves) -- and if you don't know the spec on the cam - you can measure that with a follower and a dial indicator. It might sound complicated but it's not.

[WSSix]

x2 we need way more info about the engine to be able to point you towards which heads. Luckily, there are a ton of options out there for you that are sure to make a good gain in the power department if you have basically stock iron heads now.

[elwaupo]

It's a 350 bored 30 over with flat top pistons with a mild Crane cam (I don't know which one) and 1.92 heads with an Edelbrock Performer intake and an Edelbrock 600 cfm carborater, runs better then stock.

[GregWeld]

I'd just use some small -- as in 175cc -- Trick Flow SBC replacement heads.

Or Dart 180's


You need something pretty small for a mild motor with not that many cubic inches.

Just FYI -- My 406 uses Dart 180's.... it made 525 hp @ 5600 rpms and 550 ft lbs of torque @ 4600 rpm's with the Dart Pro1 180 heads.

Too large of a head will make a lazy lousy motor. So don't get caught up in the bigger is better disease.

[WSSix]

If you can afford to have the car taken apart for a little bit, it might be worth the effort to first take a head off and cc the combustion chamber. That way you know for certain your current compression ratio and can select a new cylinder head accordingly. Of course, you can always go with a larger cc head and simply angle mill it before putting it on the car. Too big of a combustion chamber and you'll lose performance. Too small and you damage the engine.

[RBuhr69]

I would listen to these guys, just had a conversation with a friend of mine yesterday and he has 210 heads and installed the MSD EFI kit wanting better fuel economy from the motor. Well low and behold talk to his engine builder and it does not work because the heads are too big and he is just filling the motor with fuel and not burning it fast enough. Motor was built to run around 3K but going down the highway he is only ay 2k....So he has to either change rear gears or go to smaller heads to get economy versus more of a power motor...

Something to consider..

[GregWeld]

The problem always arises --- because the "bigger is better" syndrome takes over --- which really SHOULD BE -- "THE COMBINATION OF PARTS" that all work together.

It's all about the combo.


Most end up with motors that are lazy and no fun to drive around town... because they built with all the top of the line WIDE OPEN THROTTLE parts.

In a street car -- where 90% of the time you're just cruising around -- you want TORQUE and you want TORQUE just off idle... you want to FEEL that power every time you tickle the throttle. Having a motor that makes a particular horse power number at the top of the rpm range in a street car is just no fun.

That's not to say you can't have decent horse power AND bottom end torque. But you have to plan the build with those goals. Otherwise you end up with just a pile of expensive parts that make a better boat anchor, than a motor that's fun and sounds bad ass.

[GregWeld]

I'd add that there's a couple things I'd take the time to do BEFORE you buy anything.

I'd take a CYLINDER PRESSURE reading off every cylinder -- to see what kind of cylinder pressures you're current motor is making. That way - when you take your heads off to see what you have... you'd know if you can squeeze down on the chamber size - or perhaps go bigger. But if you don't have a "base" of education to start with - you're just guessing.


I'd also do a leak down test on the current motor... to check it's health before you spend a bunch of money on heads and go fast parts only to find out you're wasting your time and energy.

Heads and EFI are going to cost you $3500 bucks... for barely much more you can buy a COMPLETE engine with EFI and aluminum heads.... I only paid $4500 for a complete Smeding Performance 383 stroker motor with FAST EFI! All tuned all done!

It was "on sale" but my point is - with a bit of shopping you might be able to do a motor swap instead of a head and efi job. Your motor should be worth "something".... if it's decent and runs decent... so you'd subtract that from your cost as well.

[elwaupo]

Been awhile since I've touched on this subject and a lot has changed since then so maybe I can get some questions answered. I was planning on installing an Edelbrock Pro Flo EFI system and thought I would changed the heads while I was at it but I'm thinking of selling the EFI and motor and just going with an LS motor since they are getting so cheap now that the market has a lot more motors on hand. My question to you GregWeld is how happy are you with that 383 motor/EFI motor?

[gnx7]

Like Greg said..... maybe just get a different motor.

I would get 2 sheets of paper and see how much it would be to add alum heads and EFI to your motor..... and another sheet to calculate the cost to simply buy an LS1/2/3 pullout.

You could save 80+lbs and make a lot more power with a more modern engine.

[GregWeld]

Been awhile since I've touched on this subject and a lot has changed since then so maybe I can get some questions answered. I was planning on installing an Edelbrock Pro Flo EFI system and thought I would changed the heads while I was at it but I'm thinking of selling the EFI and motor and just going with an LS motor since they are getting so cheap now that the market has a lot more motors on hand. My question to you GregWeld is how happy are you with that 383 motor/EFI motor?



Sorry --- missed your post....


The Smeding built 383 / EFI motor is great... and for what it's in (my 32 Ford Roadster) it works perfectly. I'd still never put money into a SBC build vs buying a crate LS platform. Unless you're going for some looks or using parts you already had on the shelf - thus making the SBC motor way way cheaper and you were on a tight budget. If I wanted to use a carb -- I'd just get an LS motor and run the Edelbrock carb manifold and controller on it. Super simple - light weight - bad ass... and upgradeable going forward with a simple cam swap etc.