Crank identification - 3.4 DOHC - Is it better?

[davida1_hiwaay_net]

You would need custom pushrods and modify the guide plates at the very least. You would need to use all the mpfi top end (heads up) on the sfi lower end (block)

Yeah, that's the plan. It needs to LOOK like the original engine from above. The turbo will make up for any lesser flow performance from the iron heads versus the SFI induction.

[Guest]

Look into doing "lead in" and/or "lead out" grooves in the bearings. I did this on my Franken60 and seemed to work well, with the 2.8L block (1986 S-s10 block). Only do one or the other type of groove in a bearing, which way is which is eluding me right now.

--==edited for correct part reference==--

[davida1_hiwaay_net]

Look into doing "lead in" and/or "lead out" grooves in the bearings. I did this on my Franken60 and seemed to work well, with the 2.8L block (1986 S-s10 block). Only do one or the other type of groove in a piston, which way is which is eluding me right now.

I looked at King Engine Bearings for this engine, and they have the small groove in the lower main insert. I guess that's the lead-in groove. I like that and will probably order those, IF I can get them.

Thanks. By the way, looking at your sig, this engine is similar. I'm using a distributor with MSD but same Code$59 program.

By the way I did not get a 3x00 engine. The top end did not scare me, but the oil pan is totally different, bolts to the main caps and is not compatible with the old school front timing cover. So I got a 1991 model 3.1 engine. I tore it down to a short-block at the yard and they only charged me $90 for everything from block down. I'm tearing it down and it is *LIKE NEW* Very very happy.

Sincerely,
David

[caffeine]

Any 87+ cover should bolt to a 3x00.

[Superdave]

I had a 2.8 Camaro timing cover on my '04 3500, fit perfect other than having to plug the one hole.


So, why again are you keeping the iron heads? Just for looks?

[davida1_hiwaay_net]

I had a 2.8 Camaro timing cover on my '04 3500, fit perfect other than having to plug the one hole.

So, why again are you keeping the iron heads? Just for looks?

Yes, exactly. That's the only reason, so it keeps the early MPFI appearance. If it were mine and I was going for all-out power, I would put a turbocharged 86-87 Buick 3.8, because I have done 3 of them and have experience making that engine work well, boosted.

My friend wants this car to look like it was "back in the day" and install an old school turbo setup on it. I love these type of projects, by the way. It's very challenging to make it all work, and I like working on something different.

When I was tuning the original 2.8 before the mains went out, it was far from slow. I would bet it was faster than anything less than a high-end V8 car of the same year.

As for the timing cover, the original Celebrity timing cover bolts to the oilpan at the front; whereas the 3x00 timing cover has a casted-in curved groove where the pan fits, without bolting. Since the 3x00 oilpan is structural, bolted to the main caps, I can't keep the 85 spec 2.8 pan and use on the 3x00.

The 3.1MPFI has the same casted groove interface between the oilpan and timing cover, so I see how that would fit the 3400. But the 85 model 2.8 one is different. I had to cut the front of the oilpan gasket from the set, to use it with this engine. From the factory, there was only silicone sealing the pan on.

I got the 3.1 fully torn down. I had to because it was full of rainwater. That happened yesterday so it hasn't had time to rust. I cleaned the water off the parts and put VCI on the journals. The crank is like new. All the main bearings are 0.016US from the factory. Strange.

The only damage I found was some scuffing on 2 of the pistons. This engine looked like it had never been opened up before. The headgaskets were starting to go, and I think water seeped into those 2 cylinders and washed them down.

Will post pictures later, or tomorrow - the cold weather has given me a bit of a headache.

Sincerely,
David

[caffeine]

Is the timing cover similar to a RWD timing cover? Or Fiero style (CW water pump)?

[davida1_hiwaay_net]

Is the timing cover similar to a RWD timing cover? Or Fiero style (CW water pump)?

It has a clockwise rotation waterpump and vee-belts. Look at my other thread I think there is a picture of the engine on a stand with all accessories on it.

I found ONE lonely, abused 3.1 engine, with the upper intake manifold missing and the intake runners full of rainwater. It was my only chance, so I tore it down and found it was not rusted yet. Must have been from the rain yesterday. The car was a 91 Cavalier Z24, hit hard in the right rear quarter. Looked well taken care of otherwise, so the engine had a good chance of being usable - other than the water.

I got the engine (less the heads) for the cost of a block only, due to the water issue. Quite a deal considering the condition it ended up being in. The bottom end is near perfect. Two pistons have light scuffing but the crank is perfect, cam and lifters perfect, and there are no obvious defects.

Yes, I cut the seatbelts out of some hapless car and made lifting straps.. That was at the sugestion of the junkyard guy, by the way...


Front cover off. Looks a little varnished but the chain is no where near as stretched as the original one from the 2.8.


Camshaft out. No spalled lobes or scored journals. This is good!


Oil pickup screen is clean.


Comparison of the 3.1 piston (left) with an original 2.8 piston (right). The 3.1 piston is lighter weight. It will not put as much stress on the connecting rods at high RPM's because of less reciprocating mass. The top of the piston has a dish in it to lower the compression ratio. I will have to research it and see what kind of CR this will give. It may require new pistons with different CR.


Crankshaft rod bearing journal. Not a single scratch.


All the parts laid out, sprayed with corrosion inhibiter.

[davida1_hiwaay_net]

Here's the oilpan / timing cover setup:

[caffeine]

For future reference, a Fiero 87-88 timing cover would bolt up to a 3x00 and retain the CW water pump. The water pump on a Fiero looks the same.

[davida1_hiwaay_net]

For future reference, a Fiero 87-88 timing cover would bolt up to a 3x00 and retain the CW water pump. The water pump on a Fiero looks the same.

That's good to know, I appreciate it.

[geoffinbc]

A few oiling tips. Get yourself a small die grinder burr and blend the oil supply galley which is offset into the groove in the saddle. The saddle groove should match up well with each bearing insert. Remove the oil pump and the main and round over the large supply hole in the cap. In the oil filter mounting pad chamfer the outlet hole, remove any casting flash. Take a look in the return hole and see of any cleanup is needed. But be careful of the threads. Grind all the the oil return grooves in the cylinder heads and remove the casting ridge left behind. This will speed oil drain back.

Use a 3.1L/3.4L pump with the 3/4" pickup tube. It is a higher volume pump than the 2.8L pumps. Melling sells a high pressure version as far as I remember.

[davida1_hiwaay_net]

A few oiling tips. Get yourself a small die grinder burr and blend the oil supply galley which is offset into the groove in the saddle. The saddle groove should match up well with each bearing insert. Remove the oil pump and the main and round over the large supply hole in the cap. In the oil filter mounting pad chamfer the outlet hole, remove any casting flash. Take a look in the return hole and see of any cleanup is needed. But be careful of the threads. Grind all the the oil return grooves in the cylinder heads and remove the casting ridge left behind. This will speed oil drain back.

Use a 3.1L/3.4L pump with the 3/4" pickup tube. It is a higher volume pump than the 2.8L pumps. Melling sells a high pressure version as far as I remember.

Thanks for the tips! I'm actually preparing for those mods now. The 3.1 block is notably better quality than the 2.8 was, but it still has room for improvement. The problem now is the block is too dirty to work and my pressure wash hose is still froze. We've had some really abnormal cold weather for this area.

I see the hole between the lifter gallery and the cam bearing bore oil groove is kind of small. For the two center cam bearings, it's feeding a cam bearing, main and rods through that small port. Wonder if increasing the size of that would be beneficial?

I'll bost pictures of the block cleanup as I get the chance.

[davida1_hiwaay_net]

Ok, here are some picts of the block cleanup and grinding job.

Washed and oiled up a little. Don't like the flash rust getting in it!


Before any grinding. There definately is some flash.


The new bearings are better. They have larger oil holes as well as oil groove on the lower insert. There is quite a bit of metal blocking some of the larger oil hole.


Oil groove design. I like this.


The new and the old.


Hole size comparison.


I drilled the old bearing to the same side as new ones. It will be a pattern for modifying the block, without risking a slip of the grinder and damagin the new ones.


Pattern in the block.


Modification done. Radius and blend the oil passage into the oil groove. Widen the bottom of groove from a V shape to a U shape, and add a "toilet bowl" area to match the larger bearing oil hole.


New bearing matched up prettywell!


This one was the rear main. It was the worst. This is after modifying.


All bearings line up well now.


That gets the oil TO the bearings. NOw to get it back to the sump. The casting flash gone.




I enlarged the 3 return holes which were not too close to the cylinder bores. This should help the oil to get back to the sump instead of getting trapped in the camshaft compartment.


So tomorrow I plan to drill and thread the turbo oil return hole and get the block ready for new cam bearings. I want to have the machine shop REMOVE the old cam bearings so I can inspect and possibly port or blend the main bearing oil feed at that location.

I will have company the next few days so may not be able to do much on it. Will post back here once it's going together again.

Sincerely,
David

[Superdave]

Are you going to use the wider SBC cam bearings or stock replacements?

Good work so far on the block prep!