Post by: Fierofool on May 08, 2020, 09:40:43 pm
Post by: TopNotch on May 08, 2020, 10:22:42 pm
Post by: GTRS Fiero on May 08, 2020, 10:51:03 pm
Post by: Fierofool on May 08, 2020, 11:01:16 pm
I'm having my 2.8 injectors refurbished and don't want to put them into a bigger engine.
Post by: GTRS Fiero on May 08, 2020, 11:05:13 pm
Post by: Fierofool on May 09, 2020, 08:08:03 am
I thought 3.1's had roller lifters, so it might be a 2.8 from an 88, 89 or 90 vehicle.
Post by: GTRS Fiero on May 09, 2020, 08:27:42 am
Post by: Raydar on May 09, 2020, 08:29:48 pm
It has a crank with a trigger wheel (including the requisite notches), and a crank sensor, that apparently was not used in its new Fiero home.
Strangely enough, it also has an externally balanced (weighted) flywheel along with the neutrally balanced crank. No doubt that it was transferred from the old (86?) Fiero engine to this one. I can't believe this thing didn't shake like a paint mixer, but... oh well.
The engine appears to not have many miles on it. It's fairly clean inside, and the cylinder bores look clean, according to Charlie.
We still can't tell if it's a 2.8 or a 3.1. At least *I* can't. Someone else may be able to. Probably need to get a number of some sort off the pistons or crank, or maybe just measure the stroke.
Post by: Raydar on May 09, 2020, 08:35:42 pm
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"With the introduction of an all new V6 engine GM had to give this special engine a new crankshaft. The first 60 degree V6 crankshafts were all cast nodular iron. The 6 crankpins and the 2 center main feature deep rolled fillets making the crank very durable. The early cranks from 1980 until 1986 are all externally balanced, meaning they require additional weighting on the rear flexplate/flywheel to achieve a balanced assembly. The rotating assembly must be balanced with the flexplate/flywheel attached. Early cranks can be brought into internal balance by adding Mallory weights to the rear counterweight and using a neutral balance flexplate/flywheel. In 1987 some S-10 and Camaro's still used an externally balance crankshaft. 1987 was the first year internally balanced crankshafts were introduced. The addition of a reluctor wheel into the center of the crankshaft and the addition of a counterweight between the number 5 and 6 rod journals provided the needed mass for the crankshaft to be internally balanced. The reluctor wheel was machined with notches which provided the signal for the crankshaft position sensor. In rear wheel drive vehicles the reluctor wheel was not machined with notches because it was not required for the fuel delivery and ignition system.
Early production crankshafts use 63.35mm (2.494) main bearing diameters. For comparison the first Small Block used 58.42mm (2.30") main bearings later changed to 62.23mm (2.45") in 1968. Even with main journal diameters larger than a Small Block the 60 degree V6 was still prone to bearing failure. Beginning in 1985 the main bearings were increased in size to 67.25mm (2.648"). When selecting a crank for rebuild or replacement always seek out the later cranks. All fuel injected engines in 1985 have large main bearings but some S-10's in 1985 may still have small main bearings. In order to use a large main journal crankshaft the engine block must also be of the same style. All crankshafts since the beginning of production used a 50.7mm (2.0") crank pin diameter, the same as early Small Blocks.
The first crankshafts used in 2.8L engines had a 76mm (2.99") stroke. This stroke would remain the same until the 3.1L appeared in 1989. The stroke in the 3.1L was increased by 8mm (0.315") to 84mm (3.307"). This size of crankshaft would continue all the way through to the 3400 motor. The crank was never changed after 1989 until the 3500 motor was introduced.
Several internally balanced crankshafts featured lead in grooves on the number 2 and number 3 main bearings. These lead in groves help increase oil flow to the rod bearings. Some 1987 or later engine without lead in groves have a crank with modified oil holes that do not require lead in grooves to provide adequate rod bearing lubrication.
In 2004 GM introduced a 3.5L engine that saw an increase in the bore to 94mm (3.70") but the crankshaft retained the 84mm (3.307") stroke. However this new crank was forged in some applications and can be identified by its rougher shape and wide parting lines. The other interesting feature was its large 57.125mm (2.249") main journals which would allow for offset grinding to increase the stroke of an engine when using rods for a 50.7mm (2.0") rod journal. This new crank saw the introduction of a new trigger wheel in the center of the crank. In applications where the old style reluctor wheel is required an external trigger wheel will have to be used. On applications that use a distributor then this change in design is not a concern.
Modifications to the stock crank are not necessary on stock or mildly modified engines. However for higher performance the regular slew of aftermarket crank modifications can be performed such and profiling the leading and trailing edges of the counterweights, lathe machining the counterweights to balance instead of drilling, polishing the casting to reduce windage and several coating options to shed oil and reduce friction. The stock cast cranks perform well in applications in the 400hp range and the forged 3500 version will handle almost anything you can make out of a 60 Degree V6."
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The Readers' Digest version... It should be easy to measure the stroke, and figure out what it is.
We might be able to find a casting number or part number on the crank.
Post by: GTRS Fiero on May 09, 2020, 09:12:44 pm
Everything prior to '87 was eliminated. The 2.8 doesn't have a letter cast into it. The 3.4 block has an "F".
Post by: NoMad on May 09, 2020, 10:32:28 pm
Post by: GTRS Fiero on May 10, 2020, 08:55:18 am
Fierosound thinks it may be a 3.1. Gonna check for other numbers on the block today.
I thought 3.1's had roller lifters, so it might be a 2.8 from an 88, 89 or 90 vehicle.
I just read through that thread, and the linked thread. Very annoying. A definitive conclusion was not really reached. So, here we are, again.
Post by: GTRS Fiero on May 10, 2020, 08:57:37 am
Post by: Fierofool on May 10, 2020, 09:36:49 am
Best I have been able to determine, the pistons may be Sealed Power HyperEutectic, but I can't determine the bore. Just gonna go with what I got.
Post by: Raydar on May 10, 2020, 12:45:59 pm
The T block casting was used in FWD "W" body cars. Some of them were as low as 110 HP and as high as 135. That was with their heads and intakes. So, If the Fiero heads were such a great improvement over the old S10 and X body heads, we should be OK. I didn't check the head casting numbers, but will when I return.
Best I have been able to determine, the pistons may be Sealed Power HyperEutectic, but I can't determine the bore. Just gonna go with what I got.
The 2.8 and the 3.1 had the same bore size. The increased displacement was achieved by increasing the stroke length.
What did the tops of the pistons look like? Flat? Recessed?
My largest concern (being that I can always find the dark cloud within any silver lining) would be that they took a Gen 2 engine and dropped iron heads on it. Would yield a 7.something compression ratio.
In reality, my gut feeling is that it's probably a(n early) 3.1 minivan engine. That being the case, it probably has the "good" heads. (All the iron heads were essentially the same casting. Even the carbed S10 heads. The EFI heads just got larger valves.) The minivan also had a bit milder cam. Bad for power, but good for torque.
Ed Parks used to swap these engines into Fieros, before the 3.4s came along.
Post by: GTRS Fiero on May 10, 2020, 12:51:50 pm
Post by: GTRS Fiero on May 10, 2020, 12:52:46 pm
Post by: Fierofool on May 10, 2020, 01:13:05 pm
Steve, NoMad said the pistons looked to be dished.
I've been searching for the H5611 stamped into the head of the piston and can't find anything. I can find H562* with * being a letter of the alphabet. Sealed Power was the only one listing an H piston. Mahle were all numeric.
Post by: Raydar on May 10, 2020, 01:25:39 pm
I didn't know to look for a bypass.
Steve, NoMad said the pistons looked to be dished.
I've been searching for the H5611 stamped into the head of the piston and can't find anything. I can find H562* with * being a letter of the alphabet. Sealed Power was the only one listing an H piston. Mahle were all numeric.
Okay... You've been doing similar searching to what I have. (I'm looking at Rockauto.)
The iron head 3.1 appears to have been used in the Lumina APV through '95. It would have had flat tappet hydraulic lifters. Roller lifters, AFAIK, did not come in ANY iron head V6.
If you can't measure the stroke, you might try looking for numbers on the crank. That should absolutely narrow things down. (It would settle the 2.8 vs. 3.1 question.)
According to Rockauto, the iron head and aluminum head engines both had dished pistons. The aluminum head engines would have to have a larger/deeper dish, since the chambers were apparently smaller. Some of the "piston" pictures would tend to back that up, if you want to believe the pictures.
I'm still thinking this is a 3.1 minivan engine.
Post by: Raydar on May 10, 2020, 01:34:25 pm
What markings does NoMad's engine have?
I would be curious as to what markings the engine in Scott's "trailer queen" has, since it's also reputed to be a 3.1.
Post by: Fierofool on May 10, 2020, 01:41:38 pm
Post by: Raydar on May 10, 2020, 01:58:52 pm
I thought Scotts was a bored, stroked and cammed 2.8.
I thought I remembered hearing "3.1", but a stroked 2.8 is a 3.1. (An rebuild/overbore might make it a 3.2.) So that may be all there is to it, other than the cam.
Talking about the blue car, that y'all dragged home.
Post by: GTRS Fiero on May 10, 2020, 04:33:25 pm
Post by: scottb on May 10, 2020, 05:18:38 pm
Head casting number:
Post by: TopNotch on May 10, 2020, 08:20:08 pm
Post by: NoMad on May 10, 2020, 08:29:45 pm
Post by: Fierofool on May 10, 2020, 09:32:57 pm
Pat, do those numbers agree with the Fiero head numbers or are they for another vehicle? The 2.8 was used at least until 89 but may have had aluminum heads in the late years when used in other cars.
Post by: Fierofool on May 10, 2020, 10:17:59 pm
Post by: TopNotch on May 10, 2020, 10:20:05 pm
Post by: Fierofool on May 10, 2020, 10:33:38 pm
Post by: GTRS Fiero on May 10, 2020, 11:16:56 pm
But the two heads are identical and interchangeable side to side.
That's what I thought. So, there could be more casting numbers of which we're unaware?
Post by: Fierofool on May 11, 2020, 08:47:44 am
Post by: scottb on May 11, 2020, 05:05:47 pm
Post by: TopNotch on May 11, 2020, 07:21:03 pm
But the two heads are identical and interchangeable side to side. I found a notation that GM would change a casting number slightly during production but not change any specs of the head.It may not have been numbers for one head and the other, but just two alternate numbers for the same head. i just assumed when I saw two numbers.
Post by: scottb on May 12, 2020, 08:56:54 pm
rear head on blowed up motor
One head on 3.1 (there is a "1" buried under the sludge):
other head on 3.1:
picture proof that the heads are the same
Post by: Fierofool on May 12, 2020, 09:25:37 pm
Post by: Fierofool on May 12, 2020, 09:33:56 pm
Fiero heads are 14054884 for one head, and 14087879 for the other one on my list.
According to Pat's list, the replacement motor has the correct heads. Good news.
Got the new flywheel and pan gasket in today. New ATP flywheel bolts on the way. Got to order the poly cradle bushings.
Post by: Raydar on May 13, 2020, 07:33:37 am
Hey, Steve. Do you know what the head casting number is for the Fiero? It should be the same as the one in the blown motor. That was an original motor.
I understand that there are several casting numbers, all of which are essentially identical. The only difference is the size of the valves, and the machine work to accommodate those valves.
All of the EFI engines (as well as the carbed 2.8 HO in the X-11) supposedly got the larger valves. The carbed S10 engines got smaller valves.
Sorry. I know that's not a lot of help.