Author Topic: Latest Major Project (1981 Motorhome) (Read 3767 times)

Rockin C Racing · « **on:** November 07, 2010, 10:52:53 pm »

So I'm starting my winter projects and it begins with the biggest project. Removing the 454/TH400 combo and replace it with a Duramax/Allison combo. First step is to tear down the Dmax and inspect and replace what needs be. Here is a link to where I will be posting photos as the project progresses. Stay tuned for more.

http://picasaweb.google.com/rockincracing/MotorhomeConversion?feat=directlink

The Sad · « **Reply #1 on:** November 08, 2010, 07:26:09 am »

Looks like fun. This is for you or are you doing this for someone else?

Rockin C Racing · « **Reply #2 on:** November 08, 2010, 08:38:04 am »

This is for me. I was planning on doing it last winter, but after wrecking the bike, I couldn't work on stuff until February, and I wouldn't have had enough time to complete the project before race season began. Plus the 454 blew up on me this past Labor Day. One of the biggest reasons going to a diesel, is that I make my own bio-diesel and costs much less, so traveling/towing is cheaper.

NVMYZ28 · « **Reply #3 on:** November 08, 2010, 09:46:47 am »

Thats a project for sure! But im sure it'll be well worth it.

Rockin C Racing · « **Reply #4 on:** November 11, 2010, 08:13:39 pm »

I'm taking pictures and posting in my web album, so feel free to check it as I added a couple pictures here and there. I'm glad I'm tearing the engine down and going through it. I was told when I bought it that it blew a head gasket as water and steam was coming out of the exhaust. After pulling the heads off tonight, that is confirmed as well as I've found other issues. The first thing I found is that one of the injectors was clogged with a bunch of crap and then found the return line bolt broke on another, there for dumping the return diesel into the valve cover, then running down to the pan. That would explain why when you pulled the dipstick, it had a strong diesel oder in the crank case. Better to find this stuff now then later.

DaBo_Z28 · « **Reply #5 on:** November 14, 2010, 03:59:35 pm »

Sure is gonna be neat when its done

Rockin C Racing · « **Reply #6 on:** December 03, 2010, 08:38:09 pm »

Well here is what it looks like today.

Note the size/diameter of the cam journals in relationship to the crank journals. I can't believe the size of some of these parts. Everything is HUGE!!! Yet the pistons are only 4.030. What I've found so far is.......... it did push a head gasket passenger rear (between #5 & #7). Cylinder numbering on the duramax is driverside front to back 2,4,6,8 and passenger side front to back 1,3,5,7. I found #6 injector had some dirt and crap in it where the pressure side fuel line connects. The big problem (IMO) was that #7 injector return line had broke off the injector, thus dumping the return diesel on the heads under the valve covers, thus running down into the crank case. When I took the oil filter off, nothing but black diesel dumped out, so I was worried that there was some bearing surface damage. All the rod bearings looked normal/good considering 220k miles. The mains on the other were starting wear due to lack of oil. The front main was the worst and had some scarring on the bearing, but no damage to the crank itself. So now to order new rings, bearings, and gaskets.

The Sad · « **Reply #7 on:** December 04, 2010, 02:48:41 pm »

Looks like your making progress...

Rockin C Racing · « **Reply #8 on:** December 04, 2010, 05:43:52 pm »

It has alot of architecture similarities to the LSx based engines. It has a front mounted oil pump, the way the deck looks with the lifters, etc.

The Sad · « **Reply #9 on:** December 04, 2010, 07:42:14 pm »

Hmm, that's cool - I didn't know that.

Rockin C Racing · « **Reply #10 on:** December 26, 2010, 07:25:22 pm »

Re-assembly has begun

Rockin C Racing · « **Reply #11 on:** December 27, 2010, 09:00:06 pm »

Tonights activities after work.

ALTRDTA · « **Reply #12 on:** December 31, 2010, 01:33:26 pm »

Looking good man! Should be nice to drive that home on wheels after this upgrade!

Rockin C Racing · « **Reply #13 on:** January 01, 2011, 06:50:15 pm »

Here it is today.

At a stand still until front and rear seals come in. The engine stand is at it's limit, so I need to get the rear adaptor plate on so that I can put the sump of the oil pan on and then set it on the ground to finish it up.

ALTRDTA · « **Reply #14 on:** January 02, 2011, 02:35:10 am »

I've got an engine stand that will for sure withstand the weight if you wanna borrow it. I am in West Jordan. Let me know! Looks like you're making good progress by the way!

Rockin C Racing · « **Reply #15 on:** January 02, 2011, 10:08:10 am »

Thanks, but it is evident that you don't know me as I'm no where near you. I now live in Vancouver, WA.

ALTRDTA · « **Reply #16 on:** January 02, 2011, 04:09:38 pm »

That poses a slight problem. haha. Well, good luck with it then. Are you planning to build the trans on it? Bigger turbo/injectors in the future or during the rebuild? What engine is this btw? LB7, LLY, LBZ?

Rockin C Racing · « **Reply #17 on:** January 02, 2011, 05:36:56 pm »

This is an LB7 (I also have a LLY in my truck). I'm leaving most everything stock other than the tuning. I had the injectors flowed, cleaned, and throroughly gone through as I know the LB7 injectors had problems, but these are all good. It will be around a 450 hp tune which has proven powerful enough and realiable. That is about the limit of the stock Allison, so it will get some small upgrades, but nothing major as that drives the cost way up. I'm doing a full transgo shift kit (junior doesn't do much for the 5 speeds) changing the booster valve, and at minimum change the C3 clutches, and inspect the wear of the C1 and C2 clutches. After I get the engine done, I will get the trans up on the stand. All the work I need to do can be done through the front (removing the pump). I still need to get outside and start removing the old drive train. Really need to get the TH400 out before the end of the month as I'm going to a swap meet and would like to sell it there.

Rockin C Racing · « **Reply #18 on:** January 04, 2011, 10:21:41 pm »

Got my rear and front seals and installed them in their respective covers/plates. Got the oil pan on and off the engine stand. It now is sitting on the ground

Hanging from the hoist.

Rockin C Racing · « **Reply #19 on:** January 05, 2011, 09:56:25 pm »

Well I discovered why the return fuel line bolt broke. The retainer bolt to hold the injector in, the hole was stripped out, thus letting the injector move out of the cup. This was also on the same cylinder that blew the head gasket. It looks like the last time who ever changed the injectors stripped the hole out and didn't say anything. My guess it was done at the dealer, and the tech didn't want to have to pay for a new head. Luckily I was able to tap it to the next size up and went and bought a new bolt for the new threads.

j555 · « **Reply #20 on:** January 06, 2011, 08:42:16 am »

lookin good

The Sad · « **Reply #21 on:** January 06, 2011, 12:26:11 pm »

Glad you caught that. Keep up the good work!

NVMYZ28 · « **Reply #22 on:** January 07, 2011, 07:47:48 pm »

Quote from: Rockin C Racing on January 05, 2011, 09:56:25 pm

Well I discovered why the return fuel line bolt broke. The retainer bolt to hold the injector in, the hole was stripped out, thus letting the injector move out of the cup. This was also on the same cylinder that blew the head gasket. It looks like the last time who ever changed the injectors stripped the hole out and didn't say anything. My guess it was done at the dealer, and the tech didn't want to have to pay for a new head. Luckily I was able to tap it to the next size up and went and bought a new bolt for the new threads.

..... and people trust these "experts" with their 50k trucks

Rockin C Racing · « **Reply #23 on:** January 11, 2011, 10:03:43 pm »

I didn't do any work this past weekend since we were at the NHRA Division 6 awards banquet (Angii recieved gracious lady of the year). But I'm trying to get back to it this week when I get home from work in the evenings. Here is today and yesterday's progress. Finished cleaning and installed bottom half and top halves of the valve covers (yes each cover is 2 pieces). Got all the fuel lines on the engine all connected up from the fuel pump to the fuel rails to the injectors.

Rockin C Racing · « **Reply #24 on:** January 21, 2011, 01:14:57 pm »

Well I haven't been doing as much with the diesel lately due to a bunch more research and trying to find parts. But I finally have it all put back together. After a complete tear down and rebuild, I only have 1 bolt left over that I didn't get put back somewhere. :sm032:

Here it is. All that is left to put on is the starter and the wiring for the starter and batteries.

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Author Topic: Latest Major Project (1981 Motorhome) (Read 3767 times)