Removing the RV out of the 620

1972-1979 Datsun 620 forums. All 620-specific topics and discussion can be found here.
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Car: Mitsubishi Eclipse GT 2011, 3.8L V6, 6 Speed manual
Trans Am 1981 with dead motor
Datsun 620 1979 (Motorhome, to be converted to pickup)

Removing the RV out of the 620

Postby NoradIV » Sun Jul 03, 2016 3:23 pm

Hello everyone, first post here.

I just got a Datsun 620 as a free gift. My father rebuilt the engine, fixed most of the problems, then when he realized this thing wouldn't go faster than 55-60 mph, he tried to sell it for 1500$ and no one called within a year.

So, seeing that I was interested, he gave me the thing. I was never interested in a RV, and he knew that, but I saw this as what it was, a perfectly working 620 with no rust.

I live near Montreal (canada), and these things are so rare, I have never seen one before.

So, what I want to do is get the RV out of this and bring back the 620 back to its glory.

Before posting, I tried to gather as much information as possible. I've taken pictures so I will walk you through it. I made an imgur album if you want to see the pictures in higher resolution. (cannot post links yet, so here it is: )

So, here is the thing.
The list of problems with this truck are the following:
1. There is a fairly big loose in the steering box, I'd say at least 1' 1/2 worth of no action in the steering wheel.
2. The carburetor is running pig rich.
3. There is a bad ground somewhere, which affect everything in the dash and the radio. I have to retrace that.
4. The plug-my-usb-adapter (lighter) does not work.
5. There is a heavy piece of useless crap on it that has to be removed. I have highlighted (See arrow on picture below)

6.This is a fine paint job!

7. The cab structure has been compromised. The company who bought these and turned them into motor homes (unik) did such a horrible job in order to keep the cost low, I am honestly surprised they could pass safety laws. I could never do this legally in Canada.

The good thing is, these are the only "problems" this thing has. Everything part of the truck works pretty good, most of the motor home parts are okayish too, aside of water leaks in the roof, it is somewhat decent.

So, this truck has a wheelie-capable L20B engine that does not really rev past 4500 RPM, a not-quite-highway-friendly four on the floor, double wheels in the back, no AC, no power steering, boosted brakes, disks on the front (which are clearly insufficient for this application) and a trailer hitch, because all you want on this 100hp beast is even more weight to carry around.

The modifications done by unik seems to be a double set of rims, one bolted on top of each other (yes, you bolt the first on the truck, then you bold the 2nd on top of it), with a spacer in between; added leaf springs (there is 7 total) and probably changed the ratio in the rear end because it rev at 3500 rpm at 60mph, and the redline brings a light-speed of 15 mph in first gear.

So, here is the interesting part. I want to turn this back to a pickup truck. This looks like a body on frame truck. I was thinking about unbolting the RV part of it, have an expert make some sort of A-lookalike rollbar, get a windows, some sheet metal and weld a roof back on it. I have not been to locate a 620 bed in quebec at all, so I was thinking to either get one from another truck entirely and make it for, or just make a flatbed on it, then change to a bed when I find one, remove the 2nd set of wheels, change the axle ratio, fiddle with the lights, find original side mirrors and call it a day.

Anyone has ideas, suggestions, requests, documentations, free beers?

Thanks for your time!

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Re: Removing the RV out of the 620

Postby AZhitman » Thu Jul 21, 2016 12:25 am

Welcome aboard!

Well, wow. Where to start?

In all honesty (I've owned a couple 620s, and am restoring one now), converting her back may be a huge undertaking, for minimal gain. The biggest issue is going to be replacing the roof - unless you're a damn fine welder, you're in for a LOT of work there (with the multiple layers of structure).

It is indeed body-on-frame, but I suspect by the time you buy a 620 roof and bed, and rear axle, and correct wheels, springs, etc, you'll be into it for a ton of cash. I think I'd find a 620 that needs a drivetrain, swap the good L20b into it, and part out the camper.

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