nd4spd42085

this is my first post...

I'll briefly introduce myself... I'm 23 years old... went to a vocational school for automotive and have always been a fan of wrenching and fast cars...

it all started when I was 16 in my 1991 Olds Quad 442 w-41... man I beat that car into the ground... and after about 2 years of savage beating the bearings failed... I still have the motor and have since rebuilt it, but the car was scraped some time ago, still regret it too...

Last year I was working for Penske, and about 6 months into it I purchased a 2001 c5 black on black 6spd... gorgeous car... but it didn't last long, through a lack of money and the reckless life I led for myself, the car was taken from me after only 6 months... I was crushed... I saught the C4 but wasn't near as impressed... so I decided to look at 80's f-body cars...

about 4 months ago I went to look at an 84 camaro, I didn't really like it that much, but he said he'd throw in the parts car... I asked what it was, and he showed me, it was a 1987 formula 350, fully loaded with the lsd rear.... the engine was in terrible shape and the car was missing a left side door, a squirrel, a family of mice, and assorted spiders of all shapes and colors inhabited it. I offered him 150 bucks and took it on the spot... and for the next month and a half following, I toor the car apart and put it back together... which I documented by photos, every step... now has a rebuilt 5.7L 350 that originally came from a silverado. slapped a edelbrock performer carb with a holley 4bbl on it now with a flowmaster exhaust, headers back... brand new interior, all the body panels that were damaged repaired, or replaced, just waiting for a paint job...

I decided I needed something for a work vehicle that was just as much fun to drive, so I started looking for a v6 f-body... found a 92 camaro rs 25th ann. with a good interior. The car isn't modified at all, but has some valve train damage with 98k original miles... 500 dollars later and it brings the story to where I am now. I'm purchasing a 2.8L from my friend nick, we are pulling the engine from an 87 camaro berlinetta. From what I understand, the only difference in these motors is the crank, rods and pistons. is it possible to take this 2.8L and cram the "", "", and "" from the 3.1L that are undamaged and put them in the 2.8L without a hassle? what's involved? has anyone done this? I'd appreciate a quick reply since most likely I'll be swapping over the 2.8L tomorrow. I might just drop the 2.8L in for now so I have a mobile vehicle and mess with the 3.1L later...

either way, I've heard great things about this forum, and I'm happy to be here. Great to be in a place where everyone loves their cars as much as I do...

Thanks in advance guys,
Rob

Dale

iTrader: (12)

there are lots of little things that are different. Around 87/88 is when they switched from external balance to internal. IIRC that is when they also change the rear main size.

So, it IS very possible(and has been done). but you may have to modify one or the other part to make them match. Make sure you also use the/a matching fly/flex/balance on the crank.

The rods are the same. But the crank and pistons are different(2.8/3.1).
Also know, the 3.1 has ever so slightly lesser compression then that 2.8.
The oil system in that 2.8 is not as good. Mostly, replace the pump.

nd4spd42085

so the sensors are all the same? Should I also pull the ECU off of the 2.8L I'm pulling the motor out of, or will the 3.1L ECU suffice?

Dale

iTrader: (12)

No, all the sensors and ecm are different.

You have a 92 car with a bad block correct? Your wanting to use Just the 87 block in the 92 car correct, with the 92/3.1 crank/pistons? Or thats what I had assumed with my previous post.

nd4spd42085

more or less, yes... the idea was to take the 2.8L block, swap the sensors and accessories as necessary off the 3.1L, then take the crank and oil pump off of the 3.1L which are undamaged, and put them, external balance and all, in the 2.8L. I also was unsure if the intake was the same or if I had to swap that as well... they look quite similar but I'm not sure if the injectors or fuel pressure regulator are different... to be honest I knew these blocks were very similar and wasn't sure how involved this swap would be...
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the clarify, there is a terrible valve chatter and the engine runs very poorly and stalls out after it warms up, say 20 minutes or so... I was going to pull the 3.1L apart once I got it out and use the 2.8L instead, and basically turn it into the 3.1L

Six_Shooter

iTrader: (2)

There was no change of just the rear main....

There was a change of all the main journals in 1985.5. I surprised I have to post this again on this forum.

Internal balance startd in 1987, this is a moot point since you want to use the 3.1 crank anyway. You would likely use the original flywheel or flexplate from the recipiant car (the '92), to match the tranny.

Yes, swap the 3.1 crank and pistons in. To easiest way is to leave the 3.1 pistons hung on the 3.1 rods, but just as a note the 2.8, 3.1, 3.4, 3100 and 3400 rods are all the same, dimentionally.

Heads are are the same between the '87 and '92. There was a change in '86.

Most of the sensors are different IIRC, in the physical way, electrically the same sensors (TPS, CTS, IAT, ETC) will have the same signal.

I believe there is a difference between the two years in that the '87 is MAF, and the '92 is MAP. Use the '92 electronics just to keep the swap simple.

nd4spd42085

thanks... that's what I was hoping to hear... it sounded that simple...

nd4spd42085

I just found out the 2.8L motor is from an '85 berlinetta, not an '87...

what happened to the heads in '86?

Six_Shooter

iTrader: (2)

Being from an '85, it could have either large or small journals.

The valves were increased in size in '86 on all 2.8s. I should mention there were earleir 2.8 heads that were known as "HO" heads, that had the same characteristics as the '86 and later heads. IIRC only the Fiero and Citation X-11 had the large valve "HO" heads pre '86.

nd4spd42085

is there anyway to tell whether I have the early '85 motor or the late '85 motor without dissembling it? I'll just drop the 2.8L in if I have to... but there's no need to remove a good gasket if I can't swap the crank anyways

Dale

iTrader: (12)

The intakes are different.

The 85/87 will have a cold start injector.
The throttle body bolt pattern is different.
The injectors are different.
The fuel rail is different.


85 may be carbed

nd4spd42085

I already capped off the cold start injector last night... because the injection manifold from the 92 doesn't have the connector for it...

Your experience outweighs mine Dale, I'm sure of it... but I could swear last night when I put the throttle body on top of the '85 intake manifold the bolt pattern lined up... but I'll check again and change the intake if I have to...

another thing is with all that valve noise and smoke I figured there would be obvious damage to the valve train in the 3.1L... but there isn't... I'll have to remove the heads and see what I find underneath... could a bad cam cause that much of a racket and smoke? the oil is filthy but the guy told me it was changed 200 miles before I bought it.. so it was running awfully rich I'm guessing...

nd4spd42085

well I was all but wrapped up with the 2.8L... all but a few brackets and accessories attached from the 3.1L for an easy swap...

went to pull the oil pan on the 3.1L to decide whether or not to use the crank and pistons on the 2.8L... but my mind was made up for me...

what was left of the number 2 piston was in the oil pan... got a good laugh over it... thought I'd share... 2.8L it is...

Thanks to everyone that helped me though... maybe I can return the advice at some point, or maybe you can help me next time... either way it was appreciated...

Maverick H1L

iTrader: (8)

Use the upper intake plenum from the 3.1 on the 2.8... The TB's will bolt up, but you would have to rewire the TPS and IAC from the 2.8 to get them to work. It's not the bolt pattern that's different (actually, it's exactly the same right up to the 3x00 series engines), it's the way the idle air enters the engine... 3.1 has the air passage at the rear of the TB, which is why the plenum has that square corner on it, as opposed to the nylon pipe thing on the 2.8.
You could also just swap over the entire 3.1 intake over to the 2.8, but there might be an excess of metal shavings stuck to the bottom of the intake manifold (everything above the fuel rail just carries air, so it's called a plenum). Also, you may need to swap over the exhaust manifolds, if you have AIR, and your EGR valve, since your 92 uses the "digital" EGR valve.

BTW, are you parting the 3.1? If you are, how much for the injectors? Didn't realize when I picked up a set back in Feb that I was getting a set of larger 3100/3.4 injectors that give me a rich SES code .

bl85c

iTrader: (2)

Shame the 2.8's piston was mangled, you could've got a little extra compression out of it by milling the 2.8 pistons to fit w/ the 3.1 crank. You did rehone the 2.8 block, didn't you?

nd4spd42085

actually it was the number 2 piston on the 3.1L that is in 50 pieces...

I didn't even bother taking the 2.8L apart because it ran before it got pulled so I installed it as is... except plenum up on the 2.8L is now from the 3.1L... all the accessories were swapped from the 3.1L and all of the sensors...

I didn't do any milling of any kind though... are you saying I could take the 2.8L pistons and crank and put them in the 3.1L block? interesting...

wish you woulda posted that a couple days back... engine is already installed... don't plan on pulling it again for another year at least...
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actually that's exactly what I did... swapped the entire plenum... I'm using the injectors on the current setup though along with the intake... I'm also using all of the accessories, exhaust manifolds (which fought like a bitch while I was dropping the engine back in) and sensors... do you want the 2.8L injectors?

can anyone tell me exactly what the purpose is of a tv cable, and what the car runs like without one... mine busted off, and I have a spare I'm planning on installing in the frosty goodness of 23 degrees this afternoon, but I'm curious as to it's necessity...

Six_Shooter

iTrader: (2)

The TV cable is to adjust line pressure in the tranny and signal "kick down".

If you were to use the 2.8L crank and pistons in the 3.1 block, you'd end up with eaxactly what you have, a 2.8L.

there isn't enough material on the pistons to mill off to use the 2.8L pistons on the 3.1 crank. .31" is a lot to take off. Now you could likely get away with taking closer to .26" off or so, run FWD head gaskets (they're thicker) and allow the pistons to come proud of the deck surface like the genIII pistons do, but that's a lot of work to get a bit more sqeeze on heads that don't really flow enough to utilize that extra sqeeze.

bl85c

iTrader: (2)

Heh, you made the same mistake that firstfirebird did when we had this discussion- think in terms of radius not diameter. A german fella- 'Illja-hamburg' I think, bumped up the c/r in his 3.1 by milling 2.8 pistons ~.158" (I forget the exact amount, I had it figured for 0 deck height). He had plenty of crown material after milling.

Six_Shooter

iTrader: (2)

Still not enough material to do it safely, the top ring land is already thin, to make it any thinner in pursuit of a performance gain is asking for trouble.

Dale

iTrader: (12)

If you used the 2.8 heads. Keep your 3.1's and have them rebuilt. Then install. They should be larger and better performance.

ericjon262

I've turned a cast piston into a forged one (spun a rod bearing and slpped the you know what out of the head) before, but never completely destroyed one like that!

nd4spd42085

yeah I actually have never seen that before either. On an "iron duke" 4 cylinder I busted a couple rods and spun a bearing, never shattered a piston though... still haven't, I actually bought the Camaro that way last week. The 3.1L motor that was in it ran like **** and would stall, took the intake and valve covers off cause I thought it was a lifter or a valve, but the valvetrain was fine. The guy that had it was 20 and never performed any maintenance whatsoever to the car he told me. Apparently he beat the living sh*t out of it too... At least I've got spares now...

Maverick H1L

iTrader: (8)

You might end up running rich if you use the 3.1 injectors with the 2.8. That was my problem, and why I'm ditching the 3.4 set (unless the ones that I have for the 3100 top end are bad).

I thought the cylinder head information looked funny to me. According to the Hollander interchange, the V6/60 cylinder heads were the same from 1985-1996 (FWD in Lumina APV, which continued to run the S10's TBI system), meaning FI 2.8, 3.1, and 3.4 heads were the same. There's no difference in valve or port size, so switching to the 3.1 heads, unless you P+P them and give them a valve job, isn't really worth the effort, other than to know you have new head gaskets on the engine.

nd4spd42085

Just FYI...

I had to swap the waterpump, timing chain cover and oil pan in order to cool the engine properly...

while in the process of fixing that wrong, I realized that the main ground from the battery wasn't tight... once I tightened that and put it all back together, it ran fine... I have been driving it for 2 days

again FYI

thanks for everyones help. something so simple caused such a big problem... oops

Dale

iTrader: (12)

been there, done that on the battery cable. Atleast you didnt have to pay for a tow job to get it home and find that out.