There are a lot of people with questions out there concerning what's involved with a 3.1 rebuild. Since I'm almost done with mine, I thought I'd try to help out a little.

First of all, the car is an 88GT. Being an 88, the flywheel can be reused without being balanced. Older model cars require machining or a different flywheel out of a 3.1 or an 88 Fiero.

The car had over 130,000 miles on it and had just wasted a clutch. I figured why not rebuild the motor while I have the cradle out of the car? So now it's been five months and will be most likely six from start to finish of this project. It's taken this long because I had questions on what parts to get and had to learn by trial and error. I think I've got it figured out though.

Engine machining: done by my machinst.
-block bored
-heads ported milled and assembled
-crank balanced
-pistons balanced
-rods balanced
-flywheel resurfaced
-shortblock assembled
Parts involved: parts I recommend finding yourself.
-Pistons: Federal Mogul hyperutectic #H562CP for a '90 Camaro/ high compression $90 (Summit Racing)
-Piston Rings: ask Summit for matching Speedpros $80
-3.1 Crank: I got a new one from GM for around $350, but reconditions are cheaper
-Cam: GM performance (out of GM performance book) camshaft kit #12364059 (comes with lifters) $110
-Springs: GM performance #12363215
-Retainers: GM performance #12363216
-Rocker Arms: GM performance #14002446
(Springs, rockers and retainers cost around $150)
-Oil pump: GM performance #10051104 $80
-Water pump: new one from GM $?
-Clutch: Centerforce Dual Friction for Getrag 5 speed from Summit with throwout bearing $360
-Fuel pressure regulator: Accel #(I'll post it later) from Summit for $70

These are some of the more difficult parts to find for the rebuild. I would suggest getting all these parts and having them with you before you even drop out the engine. If there are any questions regarding the 3.1 rebuild please post them. You can email me if you want, but posting benifits everyone who is interested in this rebuild.

Thanks for taking the time to answer my questions and other's. I also appreciate the in-depth information you had on part numbers.

Again, thanks

What did the labor for the machining, balance, and assembly cost?

Eric...your 3.1 Crankshaft...was that cross-drilled...I would cross-drilled that crankshaft for better oil flow...

That 3.1 is going to purr like a cheetah.

unless you are going to race or something, crossdrilling just isnt needed, I mean the 3.1 is such a small stroke that the crank will never starve for oil. BB, yes ... 3.1 , I wouldnt bother.

I dont think there is an upgraded waterpump, I just always figured what the hell you have it off and it is only 15 bucks for a little extra insurance

Eric, What was the Grind on your cam, and do you ahve it running yet. I bought a comucam with a 250 grind, that should be mild, but I am kinda cam retarded

Why didnt you have your block decked and heads milled, I am hopeing to get away with 010 off each, well to late now, I hope it goes together alright, as soon as I get time I will put it together. I have 9 to 1 pistons so that should bump up the ratio nicely

Was all of the balancing that was done necessary? I was told that unless you are going to race you shouldn't have to worry about balancing all of that stuff. Just a question I figured I would ask about.

I still think you should cross-drilled that crankshaft...yeah it's a small mill but he decide to go turbo charging this puppy...it's better to be prepared..this 3.1 can be wicked after...

First of all, I replaced the waterpump because it's just a good idea. There's no reason to leave the old, crappy, ready to fail pump in there when a new one is so cheap.

It's quite clear that I didn't need to have all that balancing done. It does, however, make for a better running engine. All together I think the machinst's bill will be something like $1100. Don't be scared off. There were a lot of extras I had done. I've heard of people getting the entire rebuild done for a grand total of $1000.

I'm not really sure if my crank was cross drilled. My 2.8 crank was. I'll check the new one when I go back to the machine shop in about two weeks. I've heard this isn't really nessesary unless you race.

The GM cam's specs are:
Duration .050: Intake-204, Exaust-216
Lift: Intake-.427, Exaust-.454

I did have my heads milled. My machinist took 010 off of them. But it was just to clean them up. I wasn't trying to gain compression by doing it. I'm not too worried about the intake going on correctly.

I think that it is funny that we refer to the machinist as "my machinist". It's almost how my wife describes "her hairdresser". Just had to point that out

Cross drilling the crank and balancing the internal engine parts are generally considered high performance extras. If this is strictly a street engine and mainly an everyday driver, you probably don't need to do these extras. If you are planning on running the engine at high RPM from time to time, it's nice to have these extras done.

What are you going to do to make this engine upgrade work with your new computer? Is this new cam grind you have going to be compatible with your new computter? How much HP do you expect to have? I an cosidering the 3.1 strocker myself.

When my 'Burb's 454 broke a crank last summer, it broke where the crank was lightened. There was only one journal on the whole crank made this way- with a large hole in the journal end-all the others were solid. The replacement steel crank was not made this way, but was balanced along with the pistons, rods, balancer and flywheel. Even with a performance cam, the engine is silky smooth at all times and revs free up to the limiter. If you have the money, go for the balancing, the engine should live a longer, happier life but skip lightening the pieces more than necessary.

I'm getting ready to do another 3.1/3.2 motor. The last one I used a Crane compucam. Can anyone recommend a better/wilder cam that can still be used with the factory ECU (with Thermomaster chip)? Thanks.

I was wondering why you changed your fuel pressure regulator. Was this because you are thinking of turbo-ing the engine later, or was yours shot, or was there another reason?

I was also curious if you had the part # for the 3.1 crank that you got from GM. Or did you just go in and ask for one for a '90 Camaro 3.1?

Lastly, when you changed the oil pump, is this part # a high capacity oil pump? If not, do you need a high capacity one?

Unfortunately, you can't get too wild with the cam if you're using the ECM. Which CompuCam did you use? There are two different types of those Crane cams, also there is a GM high performance cam that works pretty good.

Awhile back,someone was describing how they had a 290DEG/.455lift(don't know the lobe centers)in an injected car,and how it ran great with only an increase in fuel pressure.
Was surprised to hear this since most of the time 270DEG is a practical limit with factory EFI.Don't recall the thread,maybe "performance cams",or something.

Boilermaker, I think I just asked the guys in the parts department for a 3.1 crank for an iron headed car (I'm not sure if the head material matters). I'm pretty sure it's the same one listed in the GM performance parts book. The part number is 10146900. The crank's made of nodular iron which is better than cast but not as good as steel. So it is an upgrade.

I was told by Stroker to use a fuel pressure regulator that is adjustable. I've heard both sides of this story and the way I figure, the engine suckin more air in, so doesn't it need more fuel to go with it? I'm sure it's a lot more complicated than that, but since it's advised by so many people I'll try it too. After all it only cost's 70 bucks.

Eric, the 900 crank is an updated version of the 981 crank, it is supposed to have better balancing qualities and is the way to go

Whenever you come across that part # for the fuel regulator I would be quite interested. Thanks for the answers.

It's part #74750 Accel fuel pressure reg. I would order it in the early stages of your rebuild to save time. I will let everyone know how it goes on and what to set it at.

Did you need different pushrods because of the new lifters and rockers?

Also, what exactly was done on the heads. I know you had them milled .010, but what else was done other than the normal valve job. That is my next step and want to know what to tell the machine shop.

The stock pushrods should work. I'm going to reuse mine, but many people do replace them. The heads got a valve job, new valve guides ($$$$), and they were ported (really just cleaned up). The machine shop should be able to tell you what has to be done more than I can. Maybe when I get the bill I can tell you everything they did.

I'm getting ready to invest in a cam. I am looking at the one that you purchased. Do you know what kind of HP you are expecting? Will the computer work with the cam that you mentioned in this post? Anything else that I might need to know?

I'm getting ready to get my engine back later this week, so once I get it all strapped in, could be awhile, I'll know first hand how well the cam works. A few people on this forum have used this cam and have had good results. I'm told it works with the computer. When the car is all back together with sufficient break in time, I'll report performace figures for the car (I know someone who has an accelerometer).

Just got my block back today and should have my heads back in a week or so. WOOOHOO!!!

Thanks goodness for hobbies.

i want to do the same swap you guys are doing and i was wondering what compression are you going to run and whats the estimated HP?

Boilermaker, I'm jealous. I still don't have my engine back. The machinist is going to finish it tommorow, I hope. Did you order all your parts yet (pistons, cam, other junk)?

Fierospeeder, if everything works right the engine should have a compression ratio of around 9.0-9.3:1. I used 9.0:1 pistons and the heads were milled slightly just to clean them up. The stock 2.8 has is 8.5:1, so this should lead to a substantial increase in torque and horsepower. I think nearly every part you could need, except for odds and ends, is listed in this thread. It's like the bible of 3.1 rebuilds. As far as horsepower is concerned, I expect no less than 200. I may be lucky and get even more, but what I really look foward to is the torque I should get, hopefully around 220 ft/lbs and it shouldn't be too high in the rpm band. My Yokohamas' days are numbered.

First off, I want to warn everyone about Centerforce Duel Friction clutch. It is not made by Centerforce and can be identified by the letters DUK on the preasure plate. The preasure plate has been known to not give up but fail in a big loud kind of way due to the peculiar spacing of the fingers in a "wave" pattern. THEY ARE RIPPING YOU OFF! You are paying them for their name not their clutch!
Also a more realist power number is under 200 hp for a fully built, tricked out 3.2. (Deck shaved for increased compression, 1:6 roller tipped rockers, Erson 444 lift 260 duration cam, tricked out heads going to tubular headers.) We tried but its just not there. Adjustable fuel regulators do not seem to be able to give anything more, even with higher capacity injectors. We finally had to go to the better 3.4 block to break 200 torque barrier. Yes it will feel better but the numbers for a 3.2 conversion just aren't that high realisticly. Rely on a dyno and not the "x part = x hp" method of computing horsepower.

WKDFIERO what clutch do you use or recommend. I just bought a rebuilt maxed out 3.2 dynoed 255hp at 10.5 comp and the owner said he used the dual friction Centerforce. Thanks.

During my hunt for a good clutch to use for my replacement, I was told by several well known Fiero "getrag guys" that the centerforce was a good clutch to go with and they rarely hear of any problems with them. I remember reading somewhere, I believe it was a FOCOA magazine saying something negative about the centerforce also.
Well, looks like I may be thankful that I didn't go that route afterall.

I thought that I was going to have my crank this last weekend, but that fell through, so now I have to look around. I am going with a reconditioned one. I have to get that underway so that all will fall into place. I get my heads back this weekend. I am so pumped.

I was curious about a new timing gear set. Was that necessary? Did it come with the Crank? Is there a part #? I'm going to talk to my machine shop and pick their brains a little also.

[This message has been edited by BOILERMAKER (edited 11-15-1999).]

I forget who makes it. There is a roller timing chain made for the 60 degree V6. Your crank man might know.(Cloyes?)

JEGS PN 220-9-3137 Cloyes 'TRUE' Double Roller $89.99

[This message has been edited by Tim (edited 11-15-1999).]

Just got my cam yesterday and oil pump. Boy am I getting more and more excited by the day. I must admit that I got a little enthusiastic last night and decided to put it (the cam) in. Early next week I am expecting to pick up my heads and crank.

Next step, to get the flywheel balanced (well of course pay for the heads and crank -- ouch!) and to somehow get summit to ship my fuel pressure regulator. For some reason the ACCEL part # is always on backorder.

[This message has been edited by BOILERMAKER (edited 11-19-1999).]

Can I have my old flywheel balanced or do I have to buy a new 88 flywheel?

When I did my 85 GT to a 3.1 the machine shop wanted $150 to modify my old flywheel. I got one from a 3.1 Beretta for $75 from the junk yard.

The oil pump (when compared to the old one) looks like it is oriented differently. The new one looks like the flange that is bolted up the rest of the engine is a different geometry along with the orientation of the pickup tube. I called this morning if there is a part # of the pickup tube and they told me I should use the same one that I have on the old one. This doesn't sound right, any confirmation on this?

**************

My bad, they supplied me with the wrong part #. I am glad that I checked it out when I did. Boy, that could've been costly. I will set them right today.

[This message has been edited by BOILERMAKER (edited 11-23-1999).]

Just wondering about what rods to use in the 3.1 conversion. I saw in another forum stroker said he used resized rods. I thought all 60 degree v-6's used the same rod.

Reconditioning used rods is sometimes called resizing, because the machine shop mills the cap slightly, bolts the caps back on, then rebores the holes back to perfect circles. This is not always done on a regular rebuild, but recommended for a high performance engine. Otherwise, the 2.8, 3.1, and 3.4 motors all use the same rod.