Old Crate Engine needs rebuild

[wiging19]

I bought a crate engine in 1996 and finally got it into my car in 1999 when I had the body work/painting done on the car.  I'd been stock piling car parts for three years and when the original 318 started smoking I parked the car until I found a body shop to do the body work.  Did the normal body part replacements, had the updated suspension, tranny and rear end put into the car.  Fast forward to last week we took the transmission out because it failed.  I thought it was due to a bad tork converter but last night we check the crank lateral movement on the engine to see if it was out of speck.  Of course it was way out of speck.   

I know everyone knows the crate engines need to be torn apart and rebuilt to insure they don't fail.  Unfortunately when I bought the engine the false expectation was that the engines would at a minimum meet normal production quality requirements.  So today I know I need a total engine rebuild.  I'm looking for thoughts on rebuilding the engine to improve it at a reasonable price.  I won't be doing the work but will be taking it to a mopar engine expert in my area.  Due to a buying spree for car parts for my challenger money is tighter then I would like when doing this rebuild.

Specks on the engine: it was a 360 380hp crate engine built in 1995.  It has the magnum heads.  What I have to go on the car is demon 825 mechanical secondary carb, TTI 1 5/8 headers (with 2 1/2 exhaust system to the rear), the transmission(pretty much slagged)/tork converter will be rebuilt to match the engine and the rear end gears are 3.23.  The tires on the rear are 15/60/245 (29.5 inches). 

We haven't torn the interior apart yet so we don't know what other problems are on the horizon.  So lets start with this and this time next week I can provide the facts on which parts we need to replace.  I'm just looking to understand all the options I should look at when discussing things with the mechanic on the rebuild.  Thanks. 

[PlumCraZRT]

If it's a Mopar expert it might be best to have him inspect the engine and actually tell you what is wrong.  I am sure after he tells you what's wrong you could post the results on this site and people would love to help you out.

Oh and I think an 800+ cfm carb is a little too much for a 360 cid, 380 hp engine.  ~700-750 sounds better... it would be easier to tune also.

[Chryco Psycho]

Sounds like you will need new brgs & possibly crank work as well as balancing , the engine I git was horrible for balance yo ureally need to open it up to see what all damage exists

[wiging19]

I agree that we won't know until we open it up and see what needs replacing.  Chryco is suspect you preliminary estimate might be my best case scenario.  I'm thinking of having him internally balance the engine.  My dad used to blue print and balance all his engines.  I'm leaning towards that.  The reason I had the larger carb was that I was planning on eventually replacing the heads for better flow and more hp.  Of course my headers would have to be replaced to 1 7/8 to help air flow.  Kind of sucks because I'm waiting for delivery of my exhaust system from TTI.

[moper]

Every engine should be blueprinted. And internal balancing is the best way in every case. HAve it autopsied, and go rom there. The reason it didnt last is, they dont blueprint, check, or do anything else to elevated it beyond a slap together pile of parts. The machine work is also low bidder. If it turns, ship it.

[wiging19]

  Well the engine was pulled today so by the end of this weekend I hope to have a good idea of what are the issues we need to address.  I just want to be driving my car by the end of the month and have this section of bad luck behind me.  What sucks most is I replaced the whole drive line when I started fixing this car up.  All I need now is for my 8 3/4 sure grip rear end to go and I'll be 3 for 3.    The reason I replaced everything was to insure the car was reliable.  I had mopar experts rebuild the transmission and rear end for me.  It just never occured to me that I would not be able to rely on the engine work from the factory.   

I was taught if the engine failed on you before it had 90K on the engine it was because you abused it or the company sold you an incredibly quality poor product.  No company does that because if the product is of poor quality or craftmanship their reputation suffers.  I guess that makes me a dinasaur...

[wiging19]

Well I have the initial feedback on the engine.  The bearings sheared strips on the transmission side of the crank in more than one location.  The bores on the engine look good with a little piston slap but honing will make it look good. So the bores look like they were hardly worn.  So we will be replacing it with new rings since it would be easy to do at this point.  We have to replace the main bearings.   The Crank looks like the section that was chipped could be welded and then grounded down.  The big question is what would cause pressure on the crank where the bearings would shear on one side and the other side would look hardly worn. 

I know the tork converter was bad and the flex plate was the wrong one for the engine.  The person rebuilding my engine is mystified on what caused the crank to chip and why one side of the bearings hardly looks worn. Suggesting constant pressure on the crank.  His suspensions is that the flex plate may have been bent causing this problem. The transmission person has that right now so we will get that information later today.

[Chryco Psycho]

you may need offset dowel pins to center the trans on the back of the engine ,  I have only done this with 4 spd belhousings , but if the back of the block or the trans was off it could be the problem

[Chryco Psycho]

You will need a gutted trans case to check the back of the block , bolt the trans case on & rotate the crank & watch the guage for runout

[moper]

I dont follow you about "chips" and strange wear. Can you post a clear picture of them? Thr thrust area is what usually takes the brunt of the pressure froma  bad trans or misadjusted clutch. It's the #3 main. The one with the flanges on it. And it's the rear flange that gets nailed. I posted a pic of a wiped thrust a whilago. I can find it if needed. But if the other bearings show wear on one spot or another, it could be a lot of things. Pictures of the backsides of the rod bearings, the main bearing wear areas, and the mating surfaces of the main caps would all be very helpful.

[wiging19]

  Talked to the main person working on my car.  The engine problem was also caused by the main line for the crank wasn't cut true/straight.  That explains the bearings shearing in some places and looking new on the other side of the bearing.  The #3 crank journal was hitting the #2 main web.   The end result is we are going to have the engine rebuild expert take the block and see what other items are out of wack on it.  Tentatively (if the block is usable) we are going to turn the bottom into a stroker, replace the heads, do some light porting, balance and blue print the engine.
The goal is to use pump gas, create a tight engine that should last for several years and be very reliable. 
 

[moper]

...and that is why we say crates may not be the best deal.

Also why I have every block line honed regardless of power expectations....lol.

[wiging19]

After reviewing what it would cost to get this engine where I like it I decided to just move to a big block.   What are your suggestions on selling this.  Should I offer it up here, craigs list or Ebay.  What would be a reasonable price to ask?  The block has to have the the crank journals bored straight and the same for the pistons.  The crank would have to have metal added and then lathed to proper specs.  The bores still show signs of the orignal honing.  It is a 96 magnum block with magnum heads.  I'd like to selling it as pieces for someone to do the work right instead of doing the minimum and putting it back together.  Thoughts, suggestions?

[moper]

List it as a core. IMO, it has no other value than that. I just paid $150 for two Magnum cores. One 5.2L, one 5.9. Your results may vary. But really, there's just not much fancy in it.

[wiging19]

   Interesting.  I thought the rest of the engine (heads, intake, cam, pistons, etc) would be worth a little more.  I may end up taking it all to the scrap yard.  My time and work space is worth more than that.  Especially if I have to spend ten hours of my time selling the block.  I see your point though.  There are lots of magnum engines out there so why pay more even though it was originally a 380hp crate engine.