thenewguy

if i were to get my 2.8 rebuilt, with a few performance parts, i.e, pistons, heads, etc, but nothing super expensive, should that be possible for under 2500? ive got 165000 on the engine right now, and i want to make sure that i'll be able to go for a long while to come...

Brian K

CRANE 2030 Cam with Lifters 169.99
1.52 Roler Tip Rockers 109.99
Coyles Double Roler Chain 69.99
High Flow Water Pump 89.99


Rebuild Kit with forged pistons from Summit would run you 4-500. You cna get a high powered cam form them at the time since a cam is in the kit and save the 169.99, you can also sub in the double roller for a few dollars.

Project: 85 2.8 bird

you can get a new 3.4 crate motor fromGM for under $1700.

1stgenracer

do you know how much a crate motor for a 3.1 is, and what all comes with it? thanks

Project: 85 2.8 bird

never heard of a 3.1 crate, there is Rebuild It or if you want the crate motor 3.4 crate

or you can buy used, like I wil.

TomP

Under 2500 is definately possible. Pick up the http://www.pawinc.com catalog to check out the rebuild kits. Are you doing it yourself (hopefully)? If so, you can't do it all- you'll need to get machine work done. The most basic machine work is a magnaflux; it checks the block for cracks. Next is a hot tank; it cleans the block to bare metal- but ruins the cam bearings. Next would be a bore (mainly for "cleanup" instead of power) and a hone. Finally, new cam bearings get thrown in (the tool is $180)- chevy V8 ones can be used for more bearing area, but they're a close fit... better to have the shop do it because of the risk of blocking the oil feed holes.

You can magnaflux & hot tank heads, too. You could buy new valves, but if yours are in good shape, you could just have them reground and they'll work fine. To put larger valves in our heads would not be worth the cost- unless you find 3.4 heads in a junkyard; those 3.4 heads have larger valves. You could do a homemade port job ( http://www.sa-motorsports.com 's DIY porting page) or pay big bucks for one. A valve job ensures your valves seat well to the heads.

You might want to have the crank magnafluxed & checked for straightness, and you could have it ground under to clean up the mains. Places like Northern Auto Parts will sell you a rebuilt (straight/magnafluxed/ground) crankshaft for cheap, BUT, you don't know how MUCH the crank was ground down!! If you're going for power, it might be safer to have yours ground.. you might lose 0.010", but the NorthernAuto one might be ground 0.030"!

I was told to buy my rebuild parts from the machine shop. It might be a few dollars more, but the machine shop will appreciate your purchase, and might be more careful with their machine work.

You could have your stock connecting rods magnafluxed & checked for straightness if you want to reuse them- nobody makes a "performance" connecting rod for our motors. You could have your rods shot-peened; as they're hit with the little metal *****, the metal of the rods is supposed to "compress", and that gives you a stronger rod. Definately get new rod nuts, and if you feel adventurous then you can also get new rod bolts. You might as well have them press the piston pins into the new pistons, too.

Forged pistons are $300 more than cast pistons. If you're going for an insane shot of nitrous, forged would be worth it. If you're staying conservative with your shot, you should be okay. Personally, I couldn't justify $300 extra for pistons for my 2.8; I don't want to spend that kind of bux for a 2.8- but if you're going to go insane with your motor, it's great insurance.

Bearings are cheap, as long as what you buy is what fits. That's another good thing about a machine shop; if the bearings you buy don't work, the shop can just pull another set off the shelf, instead of you sending them back thru the mail.

Buy new head bolts!!! If you do a new cam and new rockers at the same time, buy new pushrods. I found a kit (the number's somewhere on the V6 board, do a search) that includes the Crane 1.52 (or 1.60) rockers with Magnum pushrods (hardended for use with guideplates), for only $20 more. Get a whole gasket set; one from FelPro might be your best bet.

You might not need all the special tools. For isntance, if you have all the work done & parts bought from a machine shop, you probably won't need to get the bearing clearance checked. If you buy main bearings from a mail-order joint, you better get plastigauge or a set of micrometers to make sure your bearings fit. A dial indicator & stand is handy for crankshaft end-play and piston TDC. A set of mics helps with measuring crank journals, piston size, etc. A set of telescoping snap gauges (or inside micrometers = more expensive) would help measure bore & bearing size. A good torque wrench is a MUST!! You could get a dial-torque wrench, but that'll be expensive, and a click-type micrometer-style torque wrench would work just as well. You also need a set of engine brushes to clean any gunk out of the motor's insides that the hot tank leaves behind.

KED85

The heads from a 2.8 are the same as the 3.4.
The 3.4 heads COME WITH STRONGER SPRINGS & RETAINERS for the high available RPM of the 3.4 cam.
Why waste your money & time for braggin rights on a 6?
Got get a used running 3.4 for $800 & less & install it and have fun.
Brag how much you saved!
I'll take your $1500 now.

TomP

Karl, I thought you said the valves on the 3.4 heads were larger...? No?

Project: 85 2.8 bird

some extra insurance for cast pistons in nitous, get the pistons & head combustionchambers thermal coated while they're out.

KED85

Hi Tom,
The valves from the 1985 MPFI engine (our third gen), to the end of the V-6 series (the 1995 3.4) are identical in valve size.
The heads are "the same", ever so slight a casting difference.
It's the spring retainer package that makes the difference.
Plus a used 3.4 heads MAY NOT need a rebuild as quick as beefing up a used 2.8 head.
Check out the options available in the wrecking yards or head shops.