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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: ChevyJunk on April 13, 2008, 09:34:23 am

Title: '84 C-10 4.1L Crank pulley bolt??
Post by: ChevyJunk on April 13, 2008, 09:34:23 am: Hello.

A friend owns a 1984 C10 stepside with the factory 4.1L 2BBL straight 6 and 3 on the tree. It has 151K miles. The distributor mounting gasket was leaking (more like MIA). He bought a new $0.99 distributor mounting gasket and wanted me to install it. I was planning on setting the number 1 piston to TDC via the crank pulley bolt. But there is no bolt, just a circular indentation where a crank pulley bolt would normally be on other gasoline powered engines. I ended up marking the distributor in relation to the rotor, and pulled the distributor, replaced the gasket, hooked up a timing light and set base ignition timing to 10 degrees BTDC and all is fine. On a side note, his oil pump drive shaft on the end of the distributor has significant play, and he likes to rev this piece of junk around 4000 rpm, is he asking for trouble?

It is just bugging me that I can not figure out how the crank pulley is attached to the crankshaft on a chevy 4.1L straight 6.

Any ideas??
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: VileZambonie on April 13, 2008, 10:14:49 am: Are the threads visible? If not the bolt probably snapped off. If they are, the bolt is missing and just replace it. The crankshaft damper if press fit and keyed so that's why it's still on there.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: ChevyJunk on April 13, 2008, 10:21:33 am: Wow.

No threads visible, I can't stick my face directly in front of the pulley because the fan is still installed. But from what I can feel, it feels like a shank of a bolt is recessed about 1/2" to 3/4" inside the pulley. I knew something was fishy when I saw that. So, the bolt head should be in plain view?

Just another reason to rip it out and drop in a small block.

Thanks!!!
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: VileZambonie on April 13, 2008, 10:24:34 am: lol, Get an inspection mirror and a light and look better in there. Where in CT are you from?
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: Fordeatinz71 on April 13, 2008, 10:25:04 am: well, Vile is right about these being a press-fit, and i've seen 'em without the bolts before, running for years on in. are you sure that's not a pin to align the crank pulley to? i've seen this bolt missing so i guess maybe it's common?

welcome to the site! what's your poison...are you a GM guy, a Ford boy or a Dodge girl...;)

post pics of your ride if ya get a chance
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: Blazin on April 13, 2008, 10:39:00 am: Even if the pump rod didn't have play I would think revving a 250 to 4000 RPMs on a regular basis is asking for trouble.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: ChevyJunk on April 13, 2008, 10:44:12 am: (http://i44.photobucket.com/albums/f2/bluntsfolife/DSC00706.jpg)

(http://i44.photobucket.com/albums/f2/bluntsfolife/DSC00707.jpg)

He converted it to a Hurst Indy shifter.

He is from Pawcatuck, and is in Southington visting, and showed up 2 quarts low on oil.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: Blazin on April 13, 2008, 10:46:43 am: Ahh the old Hurst 3 speed floor shifter. They are such a joy to drive. Perfect H pattern or they get jambed into two gears at once. Nice tach for a 6 popper.
When he blows it up he can drop it off at my house.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: VileZambonie on April 13, 2008, 10:48:30 am: Nice... I'm from CT also... in the middle of both you guys. That truck has lots of potential! Let me know if he wants to sell it :P
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: ChevyJunk on April 13, 2008, 10:59:30 am: I tend to set him straight when he shows up, I pointed out how bad the leak had gotten since I saw him a month ago. He was truly shocked when I showed him his dipstick. He should be tip top now, ready for another month of sheer torture. I also replaced the thermostat housing gasket, the one that goes directly on the front of the cylinder head, as that gasket went MIA also. I just love how cheap gaskets are for chevys, part of the reason I have a soft spot for them.

He will never sell the truck, it was passed down from his grandfather so it has sentimental value.

I just scolded him on revving it that high. I went on my usual rant on stroke and piston speed.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: 123 pugsy on April 13, 2008, 06:40:02 pm: Don't know about sixes but my 283 didn't have a crank bolt at all. I drilled and tapped it myself.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: Blazin on April 13, 2008, 07:02:14 pm: The early motors didn't have them. They were just press fit.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: ChevyJunk on April 14, 2008, 09:16:53 am: OK so the truth finally comes out.

Press fit crank pulley on 4.1L straight 6. No crank pulley bolt.

So whats the method of setting TDC? Or is there no method cuz only retards fix em?
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: VileZambonie on April 14, 2008, 09:19:04 am: Are there threads in the end of the crankshaft snout? If there is put a bolt in it. Did you determine if it's just missing or if it's snapped off? Otherwise rotate the engine with a flywheel turning tool, the belt or by bumping the key.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: Blazin on April 14, 2008, 09:39:16 am: I meant early V8s. I have no clue about the early 6s.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: Captkaos on April 14, 2008, 10:34:20 am: All the I6's I have ever had were press fit. I have a Chevy inline book I can verify this with, but as far as I know all of them were that way.
Title: Re: '84 C-10 4.1L Crank pulley bolt??
Post by: ChevyJunk on April 14, 2008, 11:57:30 am: Thanks Capt.