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Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Mon Sep 14, 2009 10:52 am
by Jinmajay
t The #1 piston connecting rod bearing is toast and it scored the crank.

First of all this wasn't the project van. It was my wife’s van. What do you get when you put a 16 year old behind the wheel of a 1998 astro van with 110,000 miles. See the answer above.

Something about 80 MPH in second gear... :axe:

I have a 94 4.3L sitting in the barn not doing anything. Can I take that crank out and use it in the new style 1998? the old one was a CPI and did not have all the fancy stuff on it. It doesn't have the crank sensor and ring and I don't think it has the balance shaft and related gearing.

Looks like the crank is a bit longer on the newer motor. If it won't work, how much do you think it will cost to grind the crank journals down .010. How reliable is going undersize on the crank? Can you go under on the connecting rod journals and leave the mains alone? I have never done this before.

Needless to say I’m not very happy about all of this. That van was in great shape inside and out.

Oh, by the way, I was going to tow it home but the rear wheels were dragging in neutral? I checked two separate times. I had to call a tow truck to get it home. The next day it moved fine in neutral? I probably will rebuild it now that it is out.

Anyone need or want a 16 year old boy?

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Mon Sep 14, 2009 3:10 pm
by Smiliesafari
The easiest fix is a crank kit. Around here they're about $150.00. Under cut journals work fine. \:D/ And Sorry but I've had 16 year old boys. Two was about two too many. Some how they made it to adulthood. WHEW :rolleyes: :rolleyes: :rolleyes:

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Mon Sep 14, 2009 4:00 pm
by lockdoc
I hear ya. You may have seen the posts about my oldest sons van.

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Tue Sep 15, 2009 4:44 am
by Jinmajay
At least he owned up to it and didn't kill anyone in the process.

He took the crank out last night and it was all the odd connecting rod journals and the #2 main that was bad. Could it be that he ran it out of oil at such a high RPM? THe cam dosn't turn as easy as it should so those bearings will need to be replaced.

One of the rockers (stock) bounced off of center onto one of the rocker guide tits and ground a hole in top of the valve.

I will look into the crank kit. Does anyone know about the older crank. I would hate to tear into it to find out it won't work.

16 year old boy... I'm willing to pay monthly support? Anyone? He actually dosn't eat that much. Just a bad case of half of brain. I was suppost to race for the first time last weekend but instead had to be a parent. :D

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Tue Sep 15, 2009 5:23 am
by Smiliesafari
Sounds like lack of lube to me. Plus maybe trying to hit 9000 rpm. Try a search. I remember there being a thread on the interchange of parts on these 4.3's. \:D/

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Tue Sep 15, 2009 9:45 am
by Jinmajay
I don't think it will work:

http://www.gmpartsdirect.com/catalog/frameset.cfm

Crankshaft, astro, safari - 4.3l, w/balance shaft - 4.3L, W/BALANCE SHAFT
92-98 $711.82 $421.96
Image

Crankshaft, astro, safari - 4.3l, w/o balance shaft - 4.3L, W/O BALANCE SHAFT
86-94 $838.97 $610.78
Image

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Tue Sep 15, 2009 10:03 am
by Jinmajay
Wait...
When I look up the 94 safari and the 98 astro it gives the same part number? I will have to check to see if it has the balance shaft installed. Now that I think of it, it has the plastic Vortec valve covers... :-k

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Tue Sep 15, 2009 2:19 pm
by Cobra
i'm sorry what plastic...?

Re: Crank shaft compatibility question between a 94 and 98 4.3L

Posted: Wed Sep 16, 2009 4:41 am
by Jinmajay
Cobra wrote:i'm sorry what plastic...?
item number 3 above. They are plastic or composite valve covers. The interesting thing is that they say Vortec but they are actually not. The CPI intake still has the angled bolt holes as opposed to the (vortec) straight ones.