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Spare engine rebuild??? - Printable Version

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RE: Spare engine rebuild??? - DT_Duh_Trucker - 07-09-2021

(07-07-2021 )Mr Hagg Wrote:  We just open a ENGINE shop next to us should be up and running the end of this month. The down side of building engine and letting it set is not a good idea at the orings get hard over time etc......im talking like a year or so

Good to know. Definitely don't want to waste the money if it's not going in the truck in the next couple months.


RE: Spare engine rebuild??? - Rawze - 07-09-2021

(07-09-2021 )DT_Duh_Trucker Wrote:  I see your point. Just a thought that crossed my mind. I was thinking about if and when I do expand and that's where the idea came in. I'll stick with the original plan unless like you said I end up acquiring quite a few trucks. But like Mr Hagg said wouldn't want it to sit too long either.

It is a good question and conversation to have on the forum here ... There have been lots of people who have considered such things, but many of those who do so, also have not though about the possible down-sides of an investment like that.


RE: Spare engine rebuild??? - JimT - 07-10-2021

I've considered this approach recently. The key points to such an approach would be:

1) No deadline - I can acquire and rebuild the engine in my down time, at my leisure.

2) No labor costs - It only makes sense if I'm doing the work. If I have to pay someone else to do the work then the cost would be higher in the long run.

3) Unused assets - It doesn't make sense to sit on such a large investment unused for a long time. A typical quality overhaul will currently run about $15,000 in parts. Inframe labor costs could range between $5,000-8,000 depending on the shop and scope of work. If you are looking at an overhaul in 6-12 months and you follow points 1 & 2 above then you'd have a viable engine ready for swap when the time comes. The old engine can then be overhauled. At this point I would either sell the newly overhauled spare or earmark it for the next vehicle in my fleet. Either way it doesn't make sense to keep one sitting around without an express purpose.

4) Downtime - From my experience doing my own inframe last summer, at least half the time/labor is spent on taking things apart and putting them back together. This really doesn't change when swapping engines. There's still a lot of external parts to swap and some additional work removing/replacing the entire engine. All in all, the actual internal rebuild work isn't that much.

5) Drivetrain - One benefit to pulling the entire engine is the ability and ease to inspect additional components. Flywheel, clutch, transmission, seals and any components in between are all easier to access and inspect. Also, if you have to replace the crankshaft in the engine then pulling the engine might make more sense (or might be required, not sure).

In summary, my conclusions are thus. If you are planning on an upcoming overhaul, can find a good priced, good condition donor, and are doing the work yourself then it might make sense. It also makes sense if you have a large enough fleet with a rolling rebuild schedule and in-house mechanics. If you're just looking to have a spare sitting around, then no. If you are paying others to do the labor, then no. If you have some other need to pull the original engine out then having a fully built spare ready to drop in would be a benefit. Regardless of the scenario, I don't see any significant cost savings between approaches. In fact, unless you are doing all the labor yourself you're most likely going to spend more money compared to paying someone like Mr. Hagg to do the work while you take an average of a 2 week vacation (assuming you scheduled ahead of time and didn't wait until something broke).

Finally, just look at the industry for comparison. If it were more economical to prebuild and swap engines then you'd see this as the norm. In reality in-frame rebuilds are the norm with out-of-frame overhauls or engine swaps only being done when the circumstances require it. Business practices are largely determined by the impact to the bottom line and the results speak for themselves.

If you just want to spend your spare time rebuilding an engine as a hobby, then sure, go for it! But in the end you still don't want a completed engine to just sit around and collect dust. You can probably sell it for about $30-32k. This works as a hobby, though probably not a profitable endeavor for an individual.

As an aside, I mentioned that I did my own inframe last summer (at Rawze's place). It was a great learning experience and something I'd love to do again if I had the chance. But from a business perspective the loss of income from the extended down time was greater than the cost of labor that Mr. Hagg would have charged me. At the time it wasn't even on option for me as the parts used up nearly every penny I had, but in the future I'd probably pay Mr. Hagg to get me back on the road much faster which is ultimately better for the bottom line.


RE: Spare engine rebuild??? - DT_Duh_Trucker - 07-16-2021

(07-10-2021 )JimT Wrote:  I've considered this approach recently. The key points to such an approach would be:

1) No deadline - I can acquire and rebuild the engine in my down time, at my leisure.

2) No labor costs - It only makes sense if I'm doing the work. If I have to pay someone else to do the work then the cost would be higher in the long run.

3) Unused assets - It doesn't make sense to sit on such a large investment unused for a long time. A typical quality overhaul will currently run about $15,000 in parts. Inframe labor costs could range between $5,000-8,000 depending on the shop and scope of work. If you are looking at an overhaul in 6-12 months and you follow points 1 & 2 above then you'd have a viable engine ready for swap when the time comes. The old engine can then be overhauled. At this point I would either sell the newly overhauled spare or earmark it for the next vehicle in my fleet. Either way it doesn't make sense to keep one sitting around without an express purpose.

4) Downtime - From my experience doing my own inframe last summer, at least half the time/labor is spent on taking things apart and putting them back together. This really doesn't change when swapping engines. There's still a lot of external parts to swap and some additional work removing/replacing the entire engine. All in all, the actual internal rebuild work isn't that much.

5) Drivetrain - One benefit to pulling the entire engine is the ability and ease to inspect additional components. Flywheel, clutch, transmission, seals and any components in between are all easier to access and inspect. Also, if you have to replace the crankshaft in the engine then pulling the engine might make more sense (or might be required, not sure).

In summary, my conclusions are thus. If you are planning on an upcoming overhaul, can find a good priced, good condition donor, and are doing the work yourself then it might make sense. It also makes sense if you have a large enough fleet with a rolling rebuild schedule and in-house mechanics. If you're just looking to have a spare sitting around, then no. If you are paying others to do the labor, then no. If you have some other need to pull the original engine out then having a fully built spare ready to drop in would be a benefit. Regardless of the scenario, I don't see any significant cost savings between approaches. In fact, unless you are doing all the labor yourself you're most likely going to spend more money compared to paying someone like Mr. Hagg to do the work while you take an average of a 2 week vacation (assuming you scheduled ahead of time and didn't wait until something broke).

Finally, just look at the industry for comparison. If it were more economical to prebuild and swap engines then you'd see this as the norm. In reality in-frame rebuilds are the norm with out-of-frame overhauls or engine swaps only being done when the circumstances require it. Business practices are largely determined by the impact to the bottom line and the results speak for themselves.

If you just want to spend your spare time rebuilding an engine as a hobby, then sure, go for it! But in the end you still don't want a completed engine to just sit around and collect dust. You can probably sell it for about $30-32k. This works as a hobby, though probably not a profitable endeavor for an individual.

As an aside, I mentioned that I did my own inframe last summer (at Rawze's place). It was a great learning experience and something I'd love to do again if I had the chance. But from a business perspective the loss of income from the extended down time was greater than the cost of labor that Mr. Hagg would have charged me. At the time it wasn't even on option for me as the parts used up nearly every penny I had, but in the future I'd probably pay Mr. Hagg to get me back on the road much faster which is ultimately better for the bottom line.

Awesome breakdown man. I definitely see all your points good and bad. Thanks.