Starting my engine build

[toolboxchev]

Originally Posted by Mrturner1

Here's the numbers on the heads. Any idea what the bottom one means? And how do I check for decking or porting?

The number on the bottom is a special serialized number that dates back to the original owner. THAT ME! I WANT THEM BACK!

Just kidding. Probably a time stamp and code to track the original company or something?

[Coley]

Originally Posted by Mrturner1

Like camel humps?? I'm actually putting these on the shelf and installing a set of Pro Topline heads with 2.02's and 1.64's on them. As far as the ones I took off, I'm not sure what the valves or springs are, but they were paired with a Lunati 285 Bracketmaster 2 cam so they are most likey pretty decent. If they are good heads, I have a nice head/intake/cam and lifter package I need to find a home for. That's too cool of stuff to just sit around the barn

So you are replacing these 492 heads correct?....noting that the newer heads will outperform them.
Are you going to shelve them, use them or sell them...and are they fairly worn or still pretty tight?
all Good
Coley

[Mrturner1]

Originally Posted by toolboxchev

The number on the bottom is a special serialized number that dates back to the original owner. THAT ME! I WANT THEM BACK!

Just kidding. Probably a time stamp and code to track the original company or something?

Haha I knew that number was important!!

[Mrturner1]

Originally Posted by Coley

So you are replacing these 492 heads correct?....noting that the newer heads will outperform them.
Are you going to shelve them, use them or sell them...and are they fairly worn or still pretty tight?
all Good
Coley

The heads I am replacing them with will hopefully outperform them, I'm no expert on 492's though. Either way I'm gonna get rid of them though

[Coley]

Originally Posted by Mrturner1

The heads I am replacing them with will hopefully outperform them, I'm no expert on 492's though. Either way I'm gonna get rid of them though

If you were more local I'd look at taking them off your hands.
In terms of old school heads...I like these although for the trucks I'm not a big fan of the 2.02's and would prefer the 1.94" intakes to help on the low end torque/power bit.
If you advertise make sure you emphasize those 492 casting numbers, the 64cc chambers and the accessory holes in them.
There are some guys that can still make them talk with a little work and they help keep their vehicles original while still offering very good performance.
You should be able to offset a little of the money that your new heads cost you if you patiently and correctly market these....and no, do not take $50 for them....lol
My two bits...
Coley

[BrianG]

While I totaly respect the fact that you are building this motor to be 'your motor', it seems as though you are replacing some pretty decent parts on your motor. There really is nothing wrong with that all in all, but you should just be prepared for the fact that when you are done, your new motor might not have noticablly more power than it did before. You are this far, so why not finish what you have started, it will be a great learning experience and you should have pride knowing that you did it and learned a lot along the way.

You may also learn this from the whole experience... with the motor that you already had, and the money you are going to spend to rebuil it, you could have spent that same money in other places and better felt the performance gains. Such as, the torque converter that it should have had for that cam, rear end gears (depending on what it actually has) or even exhaust.

Please don't misunderstand the way I am trying to come off. I don't mean this to sound condescending or anything. Hopefully, you, I and many others will learn something here. I do honestly hope for the best for you with the motor build, I see you are having fun also, so that is definitely an added bonus. Perhaps, in the end it helps give other's an idea of where to start with power/performance upgrades. It is hard to know where to go next though when you don't know where you are starting from. Well, now you do, so as far as that goes, you are starting off in the right direction. I'm staying tuned to see how this goes.

The best of luck,
Brian

[Mrturner1]

Originally Posted by BrianG

While I totaly respect the fact that you are building this motor to be 'your motor', it seems as though you are replacing some pretty decent parts on your motor. There really is nothing wrong with that all in all, but you should just be prepared for the fact that when you are done, your new motor might not have noticablly more power than it did before. You are this far, so why not finish what you have started, it will be a great learning experience and you should have pride knowing that you did it and learned a lot along the way.

You may also learn this from the whole experience... with the motor that you already had, and the money you are going to spend to rebuil it, you could have spent that same money in other places and better felt the performance gains. Such as, the torque converter that it should have had for that cam, rear end gears (depending on what it actually has) or even exhaust.

Please don't misunderstand the way I am trying to come off. I don't mean this to sound condescending or anything. Hopefully, you, I and many others will learn something here. I do honestly hope for the best for you with the motor build, I see you are having fun also, so that is definitely an added bonus. Perhaps, in the end it helps give other's an idea of where to start with power/performance upgrades. It is hard to know where to go next though when you don't know where you are starting from. Well, now you do, so as far as that goes, you are starting off in the right direction. I'm staying tuned to see how this goes.

The best of luck,
Brian

Thanks Brian! It certainly has been a learning experience if the situation were different I'd probably be cussing and throwing a fit about finding a good bit of performance parts, but this has been fun and I don't take it seriously enough to be disappointed. I think you are right about the motor making some pretty good power before, however, each part I've removed is getting replaced with something that either allows more air or fuel or both. 600 to 650avs carb, performer to rpm intake, 492's to Pro Topline heads, Lunati .455 to a comp .490, and 2 1/4 inch exhaust to 2 1/2 or 3 inch. But it is my first time and I'm no expert I do have my fingers crossed though. I have high hopes and good confidence that she'll make a significant power increase. Worst case scenario, I've had my sights set on a 383 for a loooong time. That or a BB swap, I can see how that'd be fun

[Mrturner1]

You know what makes me a little curious, is that the truck only spun one tire and I'm almost certain the gears are stock, but when you look up a camshaft like the Lunati that was in it or the comp 280h that I bought the companies say you have to have 373's or whatever gear ratio it is they recommend. So are you supposed to have the 373 gears because otherwise you'll Break something with the kid like that? Or is that just for maximum performance? There were times when I drove that truck like it was built to be driven and nothing ever broke at all. I always thought it was funny that the truck sounded so mean and nasty but from a dead stop if I just floored it, it would barely even squeal the tires and now I know that's because the cam was so tall and the gears were still stock. It was a different story once you got over 2500 RPMs, because at that point it would drive you back in your seat and then when it second gear it would burn the tire off when it shifted.

[ptc]

Matt the whole thing about engine building is not to just build it "bigger" but to build the right 'combination' of parts to make them all work to the best possible final outcome. And also you have to define what you are using it for. Low range mid range or high end power.... they all take different 'recipes'.... Theres an old saying:

Just going BIGGER is not always better..... "Combination is King"...

So you may find yourself 2 steps back as 'Brian' mentioned above. Talk to people and learn what works.

Oh by the way I sent you some info on those heads.... those are some goodies! Grumpy Jenkins use to use those on his SBC racers pushing 600-700HP!

[GASoline71]

I have an RPM air gap on my slug and it runs fine. I live where it is cold. You just have to know how to feather a throttle until the rig gets to operating temps. Hell I don't even use a choke. I remove the choke on every carb I've ever bolted to an engine.

You need the lower gears in the rear to help the engine rev to where it makes power. You put all that "top end" stuff in there and keep 3.08's or 2.73's out back and it will be a mutt off the line.

You're putting the cart before the horse in a lot areas out of excitement. Slow down and stop buying parts until you're sure of what you have.

Take a pic of the combustion chambers on the heads. Where the valves open up. Then I can trell ya if there has been "porting" done to them. Also look into the inside of the intake runners. If the casting has been ground smooth... they've probably been port matched to some manifold.

Gary

[Mrturner1]

I think the parts I've rounded up so far compliment each other really well. I don't just think that because the parts are bigger that they will automatically work well together. I did some research before buying and put together something that should definitely perform just as I was hoping for this truck and what I use it for.

I take the truck out when me and the lady wanna get dinner and blow the tires off a few times, maybe catch a Jap trap from stoplight to stoplight, fun things like that. It's a play truck. Not driven daily, meant to be loud, snotty, and hopefully someday pull a tire off the ground a few inches. It's my first time pullin apart an engine but I'm not new to motors and fast cars in general, although I'm sure that it probably came across that way. Theres some things that I'm leaving out of this build that may hinder power and longevity a bit I.E. Forged rods and pistons with 10-1 compression and a bottom end rebuild, but that another build some other time. I will admit, I didn't plan on going this far into it but I'm sure glad I did. When this thing is back together, and the 2200-2500 stall converter is in, and the rear end has a new posi and 3.73's, it's gonna be a wild ride.

As far as more parts, I really don't need anything but to pick an intake manifold, and maybe a water pump because mine looks like it's 100 years old. Other than that it's all here already.

[Mrturner1]

Originally Posted by ptc

Matt the whole thing about engine building is not to just build it "bigger" but to build the right 'combination' of parts to make them all work to the best possible final outcome. And also you have to define what you are using it for. Low range mid range or high end power.... they all take different 'recipes'.... Theres an old saying:

Just going BIGGER is not always better..... "Combination is King"...

So you may find yourself 2 steps back as 'Brian' mentioned above. Talk to people and learn what works.

Oh by the way I sent you some info on those heads.... those are some goodies! Grumpy Jenkins use to use those on his SBC racers pushing 600-700HP!

This was a cool article. Do you know what rpm he was making that kind of horsepower?

[Mrturner1]

Originally Posted by GASoline71

I have an RPM air gap on my slug and it runs fine. I live where it is cold. You just have to know how to feather a throttle until the rig gets to operating temps. Hell I don't even use a choke. I remove the choke on every carb I've ever bolted to an engine.

You need the lower gears in the rear to help the engine rev to where it makes power. You put all that "top end" stuff in there and keep 3.08's or 2.73's out back and it will be a mutt off the line.

You're putting the cart before the horse in a lot areas out of excitement. Slow down and stop buying parts until you're sure of what you have.

Take a pic of the combustion chambers on the heads. Where the valves open up. Then I can trell ya if there has been "porting" done to them. Also look into the inside of the intake runners. If the casting has been ground smooth... they've probably been port matched to some manifold.

Gary

How much is there to be gained by port matching the heads to the intake?

[davepl]

Originally Posted by Mrturner1

How much is there to be gained by port matching the heads to the intake?

Just to be clear, never modify the head side - so you're actually matching the INTAKE to the HEAD, not vice versa. Never grind the head. And stay away from "stones", use a carbide or similar cutter.

Some say the gains are very minimal, but consider that GM even does it on the ZZ502 crate motor, so it's not exotic. And it's pretty easy to do.

You don't have to do it now though. You could make that a project for later, though you'd be pulling the top off again (intake manifold).

If you're waiting on parts or tools or books and need something to kill the time, it's a great investment of time though. Other than the dremel/die-grinder and bits, it's pretty much free horsepower, though not many.

If you're not waiting for stuff and have spare time to kill, I'd skip it for now.

[Grumpy old man]

Have you figured what you already had was making hp wise ? What about now with all the changes you've made? Seems from the parts you removed and then replaced you may end up very close to what you already had ? Have you decided on what your going to run driveline wise to handle all this new power? Posi ?

[Mrturner1]

Originally Posted by Grumpy old man

Have you figured what you already had was making hp wise ? What about now with all the changes you've made? Seems from the parts you removed and then replaced you may end up very close to what you already had ? Have you decided on what your going to run driveline wise to handle all this new power? Posi ?

I wouldn't be surprised if it was just over 300hp before. I knew when I bought it that it was pretty fast. Not a good launch that's for sure, but it screams over 2500rpm By the time I'm done, I think it'll be closer to 400hp. I haven't figured out exactly what I'm going to do with the rear end and driveline but it's getting new ring and pinion and a posi.

[tcrist]

I wonder if you had of just changed the rear gears and added a posi, how much it would have waken up what you already had.

If you are running in the 270-300 range gears now and just changed them to the 350-370 range, wonder what it would have done for you.

[GASoline71]

Post a pic of the combustion chambers.

Gary

[Mrturner1]

Here's one, they are pretty dirty still

[Mrturner1]

Closer

[Mrturner1]

I think there's work done to the intake runner but I'm not sure so I'll describe it. I run my finger in the square ports that the intake manifold sits on the heads, and it's as smooth as glass in there. And it's smooth as far as I can reach with my finger

[Mrturner1]

Originally Posted by tcrist

I wonder if you had of just changed the rear gears and added a posi, how much it would have waken up what you already had.

If you are running in the 270-300 range gears now and just changed them to the 350-370 range, wonder what it would have done for you.

Here's what I do know, if I had rebuilt the rear end with 3.73's and a posi, and done a 2200 rpm stall to match that Lunati cam, the truck would've been a rocket. It already was even with no posi, stock gears and no stall. I never doubted it was fast and the rearend and stall is going to get done regardless of what parts are going on the engine. It needed a stall more than anything, and my choice of cam will always need some stall

[Mrturner1]

Smooth part

[Mrturner1]

You can also see by the colors on the valves and combustion chambers just how far off the timing was. I hadn't bought a timing light yet and timed it by ear with the distributor. Some power to be gained there as well I'm sure.

The thing is though, as cool as all this stuff is to find, I had no idea what was in the motor before, I just knew it was fast and sounded really really awesome when it was idling and when you had the throttle wide open.

Now I have an opportunity to make it my own, and know every detail about it which is really what I wanted. I'm not an expert, but I think there's no way those GM heads can flow and make power like the Pro Toplines I got, even though they are way cool old school heads.

[Mrturner1]

Originally Posted by tcrist

I wonder if you had of just changed the rear gears and added a posi, how much it would have waken up what you already had.

If you are running in the 270-300 range gears now and just changed them to the 350-370 range, wonder what it would have done for you.

Do you happen to know what gear ratio came stock? And how I can identify my rearend?