Hey all, I have a 91 2.8l and I want to know what I would have to do to make it a 3.5l??? What bore and stroke? What pistions, rods, rings ect... looking to make a stroker. Can you guys help me? Thanks
-dirty_dann

 

Making the displacement that big, it would require a crankshaft with a larger stroke and bigger pistons. I don't know if it's even possible with the 2.8 block. Is there enough material on the block walls to make the bore a lot bigger?

Doesn't the 3.1l have thicker piston walls? If so, then it might be possible to change crankshaft and make the bore big enough. Don't know how the strength of the block will be affected though.

And everbody is going to say this, so I'll say it as well:

Get a 3.4l engine. It super. Then just bore it out and get bigger pistons and voila. There's your 3.5l

 

it would be a lot cheaper to get a 3.4 and go from there. the 3.4 is the one with the thicker walls. the 2.8 and 3.1 are the same casting block, the 3.1 just has a bigger bore. im fairly positive you cant get a 2.8/3.1 block bored that big.

 

One cannot make a 265 V8 Chevy into a 400 V8 Chevy due to not enough meat in the material for this option. In end ya start with the right engine block.
This is exactly the same analogy for a 2.8
It cannot become a 3.4 or 3.5 due to not enough meat in engine block for it to physically happen.
Buy the right tool (3.4 block) to work forward from.
And beside finding a good used low milage 3.4 engine complete not needing a rebuild is quite easy.
And swapping them under your hood is just as easy.
Do the right thing!
Used complete still running 3.4s go for as little as $210! Average is $500 range. Best choice is a low milage one not needing a rebuild like I buy for more money less in end effort. I've got about 20,000 miles on my Firebird 3.4 swap. I started with a 50,000 mile used 3.4 engine. The goal is less rebuild effort more attention to details to make a strong smog legal swap that works for very long time with zero maintenance (except oil changes).

 

Thanks for the info guys. I will be looking for a used 3.4l engine to bore out and make some serious power! thanks
-dirty_dann

 

90% of anything from a 2.8 will change/swap onto the 3.4 with no problem.
I've done it twice coached getting to 100 swappers by now it's easy, fun, detailed, worth it!
AND ya won't win every race but will sure have lots more fun trying!
That's a 3.4 under there!
2.8->3.4 long block swap boogie is the tech thread ya seek. Give a good read before ya pick up your first wrench.
ONLY 1993-1995 RWD Fbody is from where comes teh engine.
Low milage engine is key to getting back on road faster! with less work. Pay in beginning drive much longer! with less work.

 

Yes and no.

Yes the blocks are close the same depending on year. (main journel, and fuel pump prvisions).

The 3.1 has a bigger CRANK, not bore.

If you have a 1991 CAMARO, you have a 3.1 not a 2.8. Now if the engine is from that s10, then yes its a 2.8.

Only way to get a 3.5 is to bore out a 3.4

 

I have a 2.8l from a 1991 s-10 w/ 5 speed trans, 4.10 gears. Its pretty fast off the line, but I need more torque. Hince why I am tring to find the best way to go about getting more cubic inches out of the same engine, engine family. thanks

ps I used to have a 85 camero, and loved it, but that was years ago, now my little truck is my hot rod.
-dirty_dann

 

1985 Blazer
1995 3.4 engine

 

I use to have a 93 s10 with 2.8 that was beefed up quite well. I know a few "tricks" to them engines if you need help Also know quite a few websites on them also.

 

Hello Dale, I would like to know your "tricks", and the "websites" that you know about. I have decided to go with the 3.4l engine and bore it out to make it a 3.5l. What is a reasonable price for a used 3.4l engine? I'm in the market for one and dont want to get took. Thanks
dirty_dann

p.s. by the way I will have a 2.8l for sale soon hehehe

 

See my response from previous
BUt to say again
$210 is lowest we've had reported and I've paid $800 & $900 for used running complete long blocks, very low milage.
With very low milage used mills, ya just open hood, say ah & swap & close hoods & done.
Drive for many miles of smiles.
Stock 3.4 ain't anything to sneeze at. Quite a decent little mill, as is.
Buying a crate engine is also an option but now finding one is challenge as they are now discontinued. Crates go for the $2000 range.
BUT if ya planning on having fun ya can spend the money on the parts. And also can buy a "3.4 core" for less upfront, but again the trick is to get them complete, intact. Ya need alot of the 3.4 stuff to make the 3.4 work right under the original vehicle hood.
3.4 stuff to score is matching balancer/flexplate or flywheel & 3.4 injectors. Rest of the stuff ya need is found on your original vehicle engine. In end, ya mix/match take best of both options, build one engine, just right. Again see my previous pic as that's a 3.4 under there.

 

Hello KED85, on the engine that you did is that a carb on it? Also, with the 3.4l will I be able to run my s-10's TBI setup? I guess what I'm asking is can I put my 2.8 heads on the 3.4 so I can used my 2.8 TBI intake? OR Can I keep the 3.4 heads and used the 2.8 intake manifold so I can keep the TBI OR do you have a better solution? Thanks much-
-dirty_dann

ps do you have anymore pix of your 2.8 -> 3.4 Blazer swap? If so I would like to see them. You could e-mail them to:

dirty_dann_26@hotmail.com

 

The intakes of the ORIGINAL VEHICLE ENGINES swap right onto the 3.4 mill as is.
Yes you could use a TBI set up ontop of a 3.4 mill! Why not?
Just add headers & have Turbo City in Anaheim CA modify your TBI for better airflow.
I've done a carb & the MPFI set up previously shown. That's the 3.4 in my S-10 Blazer with 1985 Federal version 49 state carb set up.
One seeks the 3.4 heads. Better
How
Larger spring pockets for the larger springs.
3.4 valvetrains set designed by Crane Cam, says so in the GM Performance parts books. Air flow is the same, cause the vlave size is the same, Ya want the extra meat in the spring pocket area, less chance of cracking the head that way.
I was gonna mention that I was gonna do a V8 swap into my Blazer but decided against it due to ease of swapping in a 3.4! Everything fit just right! All I had to make was the Electric fuel pump set up as 3.4 have no provisions for mechanical fuel pump. I plan in future going to TBI fuel pump set up in the tank. Right now I have very good Carter electric fuel pump set up for the Blazer. And the 3.4 is easier to CA smog in my Blazer too.
You tell me what type of pics ya want & I may have them. In all honestly, the end result should look identical to when ya first open your hood. That's how easy is this swap. It's only detailed and planning. Rest is easy simple work.
Honest to say this, everyone who has upgraded to 3.4 power has only great things to say. Really could be up to 100 swappers by now, too.
In end, ya won't win every race, but sure will have mucho more fun trying!!!!! It's economical. I enjoy promoting this swap. Because it's such a win win situation, ya already have most the parts ya need, except the good engine to which ya rebolt the new wear out (timing chain water pump etc..) parts, anyway. Read my tech swap thread for many answers. But 99% of any questions will be easily answered when ya got the two mills side by side to examine & start reassembling. Give a shout or ask here.