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New member, Question about crankshaft by HL1986SE
Started on: 11-23-2013 08:37 PM
Replies: 16 (319 views)
Last post by: HL1986SE on 11-25-2013 12:51 AM
HL1986SE
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Report this Post11-23-2013 08:37 PM Click Here to See the Profile for HL1986SESend a Private Message to HL1986SEEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hello Everyone!

This is my first post here, as I just got my first Fiero . As my username suggests It is a 1986 Fiero SE, 2.8l L44 V6, 4 speed manual. It is in great condition, with only minor work needing done to the paint and some reaseembling of the interior. It spent the first 18 years of it's life in Florida, and had been garaged most of the time and during winter ever since. It'll soon be parked off-ground and covered with me since I have no garage. The brunt of the work needing done is the engine needing reassembled, and all the work that goes along with it.

I'm not complaining though. The car was given to me by my Father, along with all its parts and a ton of spares. I'm honored to have it, since it was his baby. He always told me it would be mine someday, and although he would have preferred to enjoy it some more and give it to me whole, long story short 4 years at the shop that never finished it was enough.

The car only has 73,000 miles. Previous owner before Dad had run the heck out of it, necessitating the rebuild. Dad had already upgraded many parts on the car also.

So, now I have an engine to reassemble. I already have the complete kit, even the new cam ,pistons, rods, lifters.. the whole shebang. New stock output Oil Pump. Cylinders have been bored .030", heads are done with new valves and springs. I even have the official shop manual, a Haynes, and a Chilton. Only thing I DON'T have is a new crankshaft. That is the point the mechanic had gotten to, to let Dad know the crankshaft was just under spec.

This brings me to my questions. I've done a TON of reading, and see mixed opinions. When I measured the crankshaft, all journals were consistently at between .0017" and .0025" below the low spec in the official shop manual. All the bearings I have are stock size, Enginetech rebuilder bearings. First.. I was like.."Well, better get a new crank". Then I looked at the clearance tolerances in the shop manual, and decided to plastiguage it.

The Clearances in the shop manual are(covnverted from mm):

Main journals .0016" to .0031"
Rod Journals .0013" to .0037"

By the plasiguage, my main jounal readings were from just under to just over .002"- worst was flattened much wider than the .003" thickness. For the rods, exactly the same. I'd say the worst reading of all would be .0022" on one rod journal. Out of round on all journals is within spec, and they have all already been polished.

So, do I dare run this crank, or am I just asking for trouble? On paper, it is fine, but then again I keep reading about oil pressure problems and the like with these engines. The engine is also just being built to stock, except for the .030 overbore. Yea..logic says everything else is new so just replace it and get it over with, but in these times and our house, $220 plus tax is a big number.

Here is a picture of the car, just after we towed it here, no engine or tranny in it, and parts boxes inside, lol.

[img]https://dl.dropboxusercontent.com/u/87824411/20131118_133607-1.jpg[/img]

I'm sure the Formula markings were put on by someone just for show, since the Formula model didn't come out until '88. It doesn't look bad though since it is the same bodystyle as one lol. I also have a set of Fi-Air-O over the roof scoops on their way as soon as the mechanic gets them back from his friend that repaired one. I know their are mixed opinions on those also. What intrigues me though is when Dad was in Florida(2004), he did some research on this car's VIN on one of these forums and found out that there were only just above 500 of this exact car made.. options maybe?..not sure.

Thanks for reading this long winded post, and it's great to be here

[This message has been edited by HL1986SE (edited 11-23-2013).]

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Spoon
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Report this Post11-23-2013 08:57 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Welcome to the forum. Your gona have a good time here.

Your link didn't work but I think I fixed it in this post.
https://www.dropbox.com/s/i...0131118_133607-1.jpg

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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tebailey
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Report this Post11-23-2013 09:28 PM Click Here to See the Profile for tebaileyClick Here to Email tebaileySend a Private Message to tebaileyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Why not have it reground? That way your sure it's up to specs.
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HarryG
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Report this Post11-23-2013 11:09 PM Click Here to See the Profile for HarryGClick Here to Email HarryGSend a Private Message to HarryGEdit/Delete MessageReply w/QuoteDirect Link to This Post
HL1986SE,
You have a PM.
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Lou6t4gto
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Report this Post11-24-2013 03:07 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Runs about $80-100 to get the crank regound to .010/.010 . then the bearings (both Rod and Mains can be had for about $50 for both) I prefer either" KING", or tri metal "Clevite" Bearings.. bearings and Gakets are no where to scrimp, if not done right, both can cause you to have to do it again.
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Blacktree
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Report this Post11-24-2013 04:15 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
The bearing clearances fall within the factory spec, so I wouldn't worry about that. However, I would suggest taking a close look at the journals on the crankshaft. They should be smooth and flat. If there's any scoring, scratches, uneven spots, etc then the crankshaft should be reground.
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tebailey
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Report this Post11-24-2013 07:19 PM Click Here to See the Profile for tebaileyClick Here to Email tebaileySend a Private Message to tebaileyEdit/Delete MessageReply w/QuoteDirect Link to This Post
I've always sent cranks out to have them either ground or if possible just polished. For the amount of damage they can cause if they fail, it's not worth the gamble to cut corners.
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HL1986SE
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Report this Post11-24-2013 09:37 PM Click Here to See the Profile for HL1986SESend a Private Message to HL1986SEEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks everyone for the advice I definitely would prefer a new crank to reusing this one. The journals are all in nice shape without scoring or any other issues.

At the moment I have the short block assembled, crank and all. It'll be some time before I am ready to put the engine into the car, and not a terrible amount of work to change the crank *IF I can roust the cash to do so. Tis the season where money is tight..lol. I'm definitely having an adventure, fabricating the tools for pressing the wrist pins and installing camshaft bearings, and of course taking my time to get everything right.

I will keep updating this or a new thread with progress. Simple question for now.. How do I get pictures to show inside the thread without an outside link. That was my intent for the pic I have up..lol

[This message has been edited by HL1986SE (edited 11-24-2013).]

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1fast2m4
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Report this Post11-24-2013 11:38 PM Click Here to See the Profile for 1fast2m4Send a Private Message to 1fast2m4Edit/Delete MessageReply w/QuoteDirect Link to This Post
Am I missing something? Spec is .001-.003 and your reading .002. that's within spec. I'll re read maybe I missed something.
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HL1986SE
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Report this Post11-25-2013 12:00 AM Click Here to See the Profile for HL1986SESend a Private Message to HL1986SEEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yep. It is well within spec, still closer to the lower end in fact. I just asked because of the horror stories I hear about these engines and oil pressure.

I'm sure it will be fine, since the clearances had to be higher before the rebuild, and the engine ran ok..lowest oil pressure was just above 40psi at idle. That was with 10w30 oil. No knocks either, just puffs of smoke from worn rings and bad valve seals. I plan on running no less than 20W oil in there to try to avoid the possibilities I read about.
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Report this Post11-25-2013 12:12 AM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just FYI, 40 psi at idle is perfectly fine. Also, don't go crazy with the oil viscosity. Thicker oil is harder to pump through the engine, which could actually be detrimental if you overdo it. The engine originally came with 5w30 oil. But 10w30 should be just fine. If you look for an engine oil with Zinc additive (ZDDP), or buy the additive separately, that should keep your camshaft and lifters happy.

[This message has been edited by Blacktree (edited 11-25-2013).]

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HL1986SE
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Report this Post11-25-2013 12:28 AM Click Here to See the Profile for HL1986SESend a Private Message to HL1986SEEdit/Delete MessageReply w/QuoteDirect Link to This Post
I definitely will be getting the additive before I start the engine And note taken I will be careful with the oil viscosity.

On a side note, anyone familiar with why there may be only 500 of this exact Fiero? or maybe a way I can verify that through the VIN?

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Report this Post11-25-2013 12:34 AM Click Here to See the Profile for 1fast2m4Send a Private Message to 1fast2m4Edit/Delete MessageReply w/QuoteDirect Link to This Post
Sorry I just figured out what I was missing, I thought you already had your crank reground and your clearance with the new bearings was .002

I would NOT buy a new crank, just take the crank you have to a machine shop of your choice, just do what they say it won't be 1/2 the price of a new crank.
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HL1986SE
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Report this Post11-25-2013 12:41 AM Click Here to See the Profile for HL1986SESend a Private Message to HL1986SEEdit/Delete MessageReply w/QuoteDirect Link to This Post
Actually, the price quotes I got for the regrind were in excess of a crank from Crankshaft rebuilders thru Advance Auto--$219. I made sure to call the supplier to make sure it was the correct one. Easier that way , no shipping and no $75 core charge..lol. The shop's reasons for saying that is the number of setups they have to do to regrind this crank since none of the rod journals line up on it.

I'm still hoping finances ease up a little so I can get a new one.. time will tell.
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Report this Post11-25-2013 12:42 AM Click Here to See the Profile for 1fast2m4Send a Private Message to 1fast2m4Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by HL1986SE:

I definitely will be getting the additive before I start the engine And note taken I will be careful with the oil viscosity.

On a side note, anyone familiar with why there may be only 500 of this exact Fiero? or maybe a way I can verify that through the VIN?



What's special about it? Unless it's a Yellow '88 with the auto trans (there was 517 of thoes LOL)
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1fast2m4
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Report this Post11-25-2013 12:45 AM Click Here to See the Profile for 1fast2m4Send a Private Message to 1fast2m4Edit/Delete MessageReply w/QuoteDirect Link to This Post

1fast2m4

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Member since Feb 2013
 
quote
Originally posted by HL1986SE:

Actually, the price quotes I got for the regrind were in excess of a crank from Crankshaft rebuilders thru Advance Auto--$219. I made sure to call the supplier to make sure it was the correct one. Easier that way , no shipping and no $75 core charge..lol. The shop's reasons for saying that is the number of setups they have to do to regrind this crank since none of the rod journals line up on it.

I'm still hoping finances ease up a little so I can get a new one.. time will tell.


It's new shop time because it sounds like they are too busy to do your job, it just doesn't cost that much to regrind a crank. and either way if they look at it it might not need any work. If they do say it needs to be reground and it's actually going to cost that much, then I guess it's new crank time.
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HL1986SE
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Report this Post11-25-2013 12:51 AM Click Here to See the Profile for HL1986SESend a Private Message to HL1986SEEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 1fast2m4:
What's special about it? Unless it's a Yellow '88 with the auto trans (there was 517 of thoes LOL)


Actually that is what I'm trying to figure out. On the outside it is just an '86 SE 2M6 4 speed, of which I think 17,000 were made? It is loaded on the options, but that doesnt seem uncommon either. I know for a fact it's not a Formula as the decals would lead on, since those were only in 1988. The owner before my dad must have put them on for show.

EDIT: I called GM with the VIN, all they could tell me is its a 1986 SE coupe, 32,000 made. That doesn't even differentiate between 2M4 and 2M6. They say the options don't stand out either. Unless some shop in Florida customized them and this is one of only 500 they did. Looks like I may have to search forums way back in 2004 to find Dad's old posts to see what he is talking about. Combing over my car I don't see anything that stands out other than the Roof Scoops,sunroof, and custom decals. He did say something about a possible factory run of .010 over engines.. Curiosity kills the cat I guess.. lol. Hopefully I can find out because the possible rarity of this car is his motivation for pressing me to keep his wishes of keeping the car original. If it isn't, and down the road this 2.8l engine gives me more crap, I'd just like to dump in the 3800SC engine.. hehe

[This message has been edited by HL1986SE (edited 11-25-2013).]

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