Engine Swap

[bandz7]

A popular upgrade for an old worn out 2.8 S10 is to swap it for a 3.4 from a 93-95 camaro.

My 3.4 is from a camaro with 115,000 miles. "Looks" really good but not completely sure being that it's from a junkyard. I had the heads done from my 2.8 only 5000 miles ago when I addressed a head gasket leak. Those will go on top without any rebuilding.

Would it make sense to purchase a re ring kit from rock auto that includes just rings and bearings? If so do you just buy the "standard" size for a stock 3.4?

 

[Trav]

No one can tell you what size rings and bearings to buy until the bores and crank have been inspected, measured and machined if necessary. You also have no idea how the pistons and rods or any other internal component are until its been taken apart cleaned, inspected and measured.

 

[skyactiv]

I've rebuilt GM engines a few times and learned they often use undersized and/or oversized bearings at the factory to get the bearing clearances
in spec. It will be indicated on the backside of the bearings. So never preorder anything before rebuilding an engine.

Do the 2.8 heads have the same flow and combustion chamber head volume of the 3.4 heads? Because if the 2.8 heads have a smaller combustion chamber, it will raise the compression and might require using higher octane gas.

 

[andyd]

can you rig a test stand to give the engine a compression test? or a leak down test? A certain amount can be judged by a look under the valve covers and looking at the condition of the plugs. I would do some googling to find out more about the 3.4

 

[Donald]

What has happened in the last 5000 miles to make you decide to swap the block now after having the heads done?

You may start down the rebuild path and along the way decide to do things like have the crank ground or cylinders bored.

I would use the 3.4 engine as is.

 

[supton]

Sounds like this is a swap "because you can".

Are the 2.8 heads the same, or do they have smaller chambers, thus the desire to reuse? If they are the same then I'd swap the entire motor. You can always swap heads later.

If not, the pull the heads and measure bore wear. That would be the first indication of wear. After that though you are stuck pulling parts and measuring, before ordering anything.

 

[BrocLuno]

It's not that big a deal to pop the pan off and pull the rod caps one at a time a check the numbers to if they are standard... Ditto the mains. Might as well put new front and rear seals in while you are in there.

Me, I'd put a new oil pump in it at least. Install a Cloyes timing set. Drill the lifter gallery end plugs 0.030" to oil the timing set better.

Clean the decks real good. While you are cleaning the decks, you can look at each bore. If they all look good, you could pull the rods/pistons - diggle ball hone the bores and put new Hastings rings in it. All this is pretty cheap and the motor will run better.

You can even bump the cam a bit. But I would not do that unless you are going to buy a premium lifter kit, and now you are talking money ...

It's a slippery slope once you open the motor... But much easier to address any found issues before it's in the truck ...

 

[bandz7]

Thanks for the responses everyone. I'll try to clear this up a bit. A 3.4L is a bored and stroked 2.8, therefore I can reuse the intake manifold, throttle body injection, cylinder heads and all my original accessories.

I had a head gasket leak about 3 years ago, where I pulled the heads and since they were off I had them rebuilt. They're basically brand new. I have a comp cam and all the components to go with it ready to get put on the 3.4L. I have new lifters, pushrods, springs, retainers, timing set and roller rockers.

My 2.8 is very tired with 250000 miles. I probably should have done this a couple years ago, but it'll get done sooner or later. The catalyst is simply that my clutch exploded and that made me want to try a 3.4.

 

[The_Eric]

Just because the heads will physically bolt on, doesn't mean that they'll work properly. Like others have said, the combustion chamber size and intake and exhaust flow can be different. A good example would be the Chevy 305 head on a 350- it'll bolt on but the chamber is too small which raise compression too high and the ports don't flow enough to properly feed a 350.

 

[Merkava_4]

4.3L is a popular swap along with a Chevy 350.

 

[bandz7]

Originally Posted By: The_Eric
Just because the heads will physically bolt on, doesn't mean that they'll work properly. Like others have said, the combustion chamber size and intake and exhaust flow can be different. A good example would be the Chevy 305 head on a 350- it'll bolt on but the chamber is too small which raise compression too high and the ports don't flow enough to properly feed a 350.


The heads are identical. Therefore using my freshly rebuilt ones is the best course of action. I should have said that earlier.

Here's a couple pics of the progress: