Crank identification - 3.4 DOHC - Is it better?

[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

[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?

[caffeine]

Any 87+ cover should bolt to a 3x00.

[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

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]

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.

[1988GTU]

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)

[davida1_hiwaay_net]

To do iron heads on the roller engine you would need to tap the heads for the roller rockers and make space for the rocker arm bodies to fit under the cover and lim. Ignition is least of your investment and concerns.

Well, I was planning to use the heads as-is with their existing rockers. Just using the roller cam/lifters. I'm most concerned with durability of the bottom end, thius wanting the newer oiling system. This isn't a high RPM build but it will see some heavy loads on the mains because of the boost. I don't think the non-roller rockers will be a problem at this RPM level.

The Buick engines used roller cam with non-roller rockers from 86 to 90 (IIRC) and those engines last forever.

I hope to look at a few core engines today to get a better idea of what is going to or not going to work.

Thanks,
David

[1988GTU]

I'm considering it. The 2.8 is really a basket case. I found the beginnins of a spalling cam lobe and lifter.

The car must retain the iron heads and original manifold setup, with distributor igintion, but I would like the roller cam and better oiling of the 3x00. If I do this, will try to get a 3400.

To do iron heads on the roller engine you would need to tap the heads for the roller rockers and make space for the rocker arm bodies to fit under the cover and lim. Ignition is least of your investment and concerns.

[davida1_hiwaay_net]

The distributor cap assemblies interchange. Are you going 3X00 now? I recommend 2000+ 3100/3400 if you do.

I'm considering it. The 2.8 is really a basket case. I found the beginnins of a spalling cam lobe and lifter.

The car must retain the iron heads and original manifold setup, with distributor igintion, but I would like the roller cam and better oiling of the 3x00. If I do this, will try to get a 3400.

[1988GTU]

The distributor cap assemblies interchange. Are you going 3X00 now? I recommend 2000+ 3100/3400 if you do.

[davida1_hiwaay_net]

Well, now I found the cam is not in good shape. Considering using a 3100 / 3400 block / crank / cam-lifters instead of this one.

I'm aware of the compression ratio and need for correct pistons, using iron heads on a newer engine. Are there any other big "issues" with this swap?

Will the distributor gear from the 3x00 "dummy shaft" work on the distributor shaft from the 2.8? I expect the gear material is different between the iron flat-tappet cam and the roller cam.

Is there a difference in the balance weight of the harmonic balancer?

Anything else to watch out for?

I'm going to junkyard to investigate a few core engines today, probably.

Sincerely,
David

Ps - sorry to ask a lot of newbie questions. I don't have a huge experience base with these engines.

[davida1_hiwaay_net]

OK got the engine torn down today. Had issues with air compressor and had to fix it to proceed with the engine. It shredded a belt on the coldest day of the year so far!

I think I have found a contributing factor for the bearing failure. The machining and alignment of the oil ports to the bearing inserts oil holes is truly awful.

Once the cam bearings are out I will be interested to see how well the intersecting passageways up there are aligned.

Combustion chambers look good. No carbon.


Intake valves are clean:


The bearing oil hole alinment is far from acceptable.

They are most all a little out of alignment. Two of them are severely misaligned.












This is very sad and GM should take more pride in their assembly procedures. I'll be interested to see what the cam bearing bores look like. Since they have the intersecting oil ports for the mains, that area could also be part of the cause of this failure.

Does anyone have good experience with King Engine Bearings? I am considering their main bearings with the extended oil groove (there's about 1/4" of oil groove on the lower main insert).

I've read up on it here, and it looks like the engine needs to have about 70 PSI oil pressure at full revvs. When I added the turbo I was trying to prevent exactly what happened, so I changed the rod bearings and the oil pump. The new Melling oil pump produced exactly 50 PSI (just like it should for a stock engine). Is there a formula for making a spacer for the spring? I will search here but would also appreciate any firsthand experience! I don't want to make it too strong and blow the filter or twist the pump drive shaft in half.

So far I'm planning:
-Correct main bearing bore oil port alignment and width.
-Check / correct oil passage alignment at cam bearings
-Oil pump spring pressure
-Check main bore alignment (take to machine shop)
-Better main bearings
-Grind flash from casting to improve drainback to sump.
-3.1 crank and pistons / basic rebuild

Sincerely,
David

[davida1_hiwaay_net]

"WHAT" noy "WHY"

Well, I was a good guesser by the sound of the engine. The center 2 mains are wiped. They show massive amounts of adhesive wear and heat damage. The front and rear mains; as well as the rod bearings are not wiped but have contamination damage form the other failure.


Did not spin in the block. That's a good thing.


Rod bearing is not destroyed. Only shows some contamination damage.


Will be replacing that crank.


Will definately be further investigating. There is a root cause somewhere. Later I will roll out the upper main inserts and inspect the oil holes. I have to take my time on the full teardown of this engine because it is a project build I had running perfectly. I want to put it back in the same condition as easily as possible. So don't know if I will have it stripped down tonight. Haven't yet seen the cam bearings....

Sincerely,
David

[davida1_hiwaay_net]

Could also be a wiped cam bearing.

Could be. That makes sense too - this car was a field car that hadn't run in many years. The cam could have rusted on a journal.

Once again - stupid me hindsight 20-20 I should have town the engine down fully when I had it out the first time.