rhyspat

Found an 85/86 engine, however the flywheel is missing.
Will my 87 flywheel fit this other engine ?.

Not sure if my 87 as internally or externally balanced.
Pic of my flywheel below

Maverick H1L

iTrader: (8)

Your 87 is EXternally balanced. The weight is on the bottom on the engine side pic.

As I've posted before, and others before me, the V6 went to INternal balance in 88, so 88-9 2.8s and all 3.1s and 3.4s are internally balanced.

Since you already have an EXternally balanced plate, put it on the earlier engine.

rhyspat

Thanks Maverick,
I did do a but some posts said it was 87 that they started doing some with internal balancing.

Wanted to make sure my flywheel was correct before I ruined another engine.

Thanks again,
Rhys

Maverick H1L

iTrader: (8)

Oh, believe me, if the engine ends up out of balance, you'll know. You'll feel it, and possibly even hear it. I messed up the secondary balance shaft timing chain on a Chrysler 2.5 and that thing shook something terrible until I got the chain timed right.

rhyspat

Hmmm, I got my car running but it vibrates like crap. No way I can drive it like that.
I'm now wondering if my flywheel was in fact internally balanced.......
The weight looking thing on the back of it in the picture is actually moulded in to the flywheel. There are no actual weights welded on to it anywhere.

Can we tell by the casting number ?. I think I can just about read it in the picture as 14033181.

What should the casting number be for an external balance flywheel? (I tried googling this but a lot of part places list these for all years.....)

rhyspat

Anyone know the casting number for me to buy the right external balanced flywheel ?

caffeine

iTrader: (2)

What year is the new motor? If it is an 88 or newer you need a neutrally balanced flywheel. The one in the picture is definitely externally balanced; I've seen both types.

Edit: I see that you posted that the new motor came out of an 85/86. Is it possible it is actually an 88+ engine? I don't really know how to tell the difference but I imagine the crank snout would have a part # on it.

rhyspat

The guy I bought the engine from said it was an older engine than mine, he seemed to think was an 86.
When I was plugging in all the sensors I noticed there is one extra sensor on the passenger side of the block (half way up and half way across the block). I wonder if the block is from an S10 and he maybe he bolted on the FI stuff (he told me it was from a firebird)

IF I do have the right flywheel, what else could be wrong to make it vibrate ?. Mis-aligned cluch or maybe I have the flywheel not in the right spot (I ligned up the hole in the flywheel with corresponding same hole on the crank - is that right ?).
One thing I have not checked is if all cylinders are firing. I double checked the firing order and all is good

This engine is really driving me

caffeine

iTrader: (2)

What does the extra sensor look like? It sounds like you installed the flywheel correctly.

Is the extra sensor in the same spot as a coolant drain plug on the old engine?

rhyspat

I will take a pic of the extra sensor tonight. Everything else was where it was supposed to be with all the correct plugs etc

Maverick H1L

iTrader: (8)

There is a boss on the oil pan rail on the starter side of the engine. Clean it off and you should find the VIN derivative (it's going to be faint but it will be there provided you didn't sand it off). Any number with the second letter higher than H (J, K, L, M, N) requires an internally balanced flywheel. Other than that, the only way to tell if the engine is anything but a 2.8 is to pull the heads or put a borescope in the oil pan to look at the crank journals (one WILL say either 2.8 or 3.1), or to find the other number on the back of the block where the bellhousing bolts up (driver's rear, IIRC).

IF the engine has a knock sensor by the starter, chances are it's a 3.1, provided that the stock engine in the donor car wasn't previously swapped for a 2.8. No 2.8 that was in an RWD application ever had a knock sensor.

caffeine

iTrader: (2)

Do 90s S10 2.8s have knock sensors? Alldata says they do.

rhyspat

My phone battery died just as I was going to take a picture of the sensor.
Will try again tonight. Car is in an awkward place in my garage right now so I can't get under it to look for numbers. The engine did have 2.8L cast in to the side of it - I know that much for sure.
Is there some way to tell from the harmonic balancer to tell if it's external or internal balanced ?

rhyspat

I managed to climb over all the crap in my garage to take a picture of the mystery sensor on the side of the block.
Not the best picture, sensor is a bit out of focus, but it was hard to get my phone in there.

So, does this mean the engine is probably a 3.1 with a 2.8 intake grafted on to it ?

So IF it is a 3.1, I guess I need a neutral balance flywheel - right ?


thanks
Rhys

caffeine

iTrader: (2)

Sorry I can't tell from the picture but does it look like this?

Screamin82 Z28

If the motor is externally balanced you would have to put weights on the appropriate spots on the flywheel and harmonic balancer to counter the out of balance parts within the motor. So if that were an externally balanced flywheel, it would have to be put on in the correct orientation in order to balance the motor properly. Perhaps try out different orientations.

Six_Shooter

iTrader: (2)

The flywheel and flexplates will only install in one way.

The balancers are neutral balance, regardless of the engine being internal or external balance. The external balancing happens with the flywheel or flexplate only.

rhyspat

Yeah, thats the sensor that on it

Screamin82 Z28

I did forget that they only go on one way... I have never had an externally balanced engine in my car but, I have done a lot of work with small blocks and I assure you both balancer and flywheel are used for externally balanced engines. As quoted from car craft since I know I am not what I would consider a reliable source.

"Most 383 stroker cranks are designed to use external weights on the balancer and the flexplate/flywheel."

Read more: http://www.carcraft.com/techarticles...#ixzz2RUgv0z7H

caffeine

iTrader: (2)

Ok so unless someone added a knock sensor to the engine, its a 3.1 or possibly a 2.8 from a 90s S10 (can't remember if they came with one). Either way it would be 88+ which means you need a neutral balanced flywheel.

rhyspat

Thanks for the Info. It would explain why it vibrates.
I have only run it for max 5 minutes total since it has all been back together. Hopefully nothing has been hurt (there is no knocking or anything, engine sounds quiet).

Guess it's stripdown time again - after I find a neutral balanced flywheel that is.

Six_Shooter

iTrader: (2)

You should not assume that just because a SBC is designed one way that all engines are designed that way. And from what I remember it was only the 400 SBC that required a specifically balanced harmonic balancer. Actually that article confirms that it was the 400 that needed the specific harmonic balancer. Which by extension means that the 383, that in origins used the 400 crank, also needed the specific balanced harmonic balancer.

The 60 degree V6 uses the same harmonic balancer whether the engine itself is an internally or externally balanced design. The additional weight is added to the flywheel or flexplate ONLY.

So please do a bit of research before posting next time.

Six_Shooter

iTrader: (2)

You could also have the weight machined or cut off your existing flywheel or flexplate.

rhyspat

One more thing.
Do 3.1's have 2.8L cast on to the side of the block. The block definately said 2.8L on it (I guess all the castings are the same)

caffeine

iTrader: (2)

I happen to have a flywheel but you're in Vancouver, right? I'm in Vic.

rhyspat

Yeah, I'm in Vancouver. I don't have and trips to the island planned right now.
You coming to the mainland any time soon ?.

If all else fails I will either get my existing machined or buy a new one. Surely cant be that much - right hehe!.

rhyspat

Hey all,
As the engine has a knock sensor, does it matter that it's not hooked up ?

Six_Shooter

iTrader: (2)

It only matters if the ECM makes use of a knock sensor.

rhyspat

I am going to go number hunting tonight when I get home. Can anyone give me a little more explaination as to where I am goign to find the engine number. Do I need to take anything off to be able to see these numbers? Can it only be seen from underneath ?

Maverick H1L

iTrader: (8)

I'm not sure if the AIR pump is in the way or not since I've never had one and never will. But it will probably be covered in rust.

There really isn't much more explaining to do. Look at the passenger's side of the engine along the oil pan rail and there will be the VIN block about an inch or so from the front of the engine. It's best viewed from underneath as you won't have the exhaust and everything on the top of the engine in the way. However, I think it may be just above the crossmember, IIRC.

rhyspat

Awesome, thanks Mav,
I have an air pump so it's probably why I could not find it. Probably tucked in behind it.

rhyspat

Could I just grind off the weight so its plat on the flywheel - or would a machine shop have to do that ?

caffeine

iTrader: (2)

Best to have a machine shop do it to verify its balanced properly

rhyspat

Ok. Finding it hard to get a new replacement Flywheel in Canada for some reason, so I'm goign to have to get the original weighted flywheel 'un-weighted'

caffeine

iTrader: (2)

You can get a brand new flywheel from rockauto.com for about $100 shipped. That's where I got mine. Just order one for a 93-95 3.4L V6 Camaro and it will be the right one (neutral balanced)

rhyspat

At last I managed to get the Firebird in to my garage to work on it again.
So I had a look at my old 2.8 engine as a dry run to see if I could find the engine number and I think I found it at the top just behind the timing cover.
Attached pic is what I found.


I scraped off the same area on my new to me engine and there is nothing there (was sanded off I guess during repainting)


I also could not find a number underneath the engine.
Can anyone point out where it might be (I took a pic of the underneath of my 2.8, hopefully someone could point it out to me.

Once I find the numbers, how do I decode them?

Thanks,
Rhys.

rhyspat

So I found the partial VIN on the oil rail. Its a little faint but I think it is an 'H'. So that means its an 87........... but why does it have a knock sensor ?. Would it be internal or external balance. What I do know is that I cannot drive it with vibrations like it has.

Anyone have any ideas

rhyspat

Dropped the transmission off, removed the clutch assembly, started the engine and vibration was still there.

Removed the weighted flywheel and installed my new neutral balanced flywheel. Started the engine and the vibration is gone.
So, it definitely means 87 had both external and internal balanced engines. Although I'm not sure what my engine actually came out of (except it was a chevy)