New AMR300 and other progress.

September 29th, 2013

This weekend I finished stripping and cleaning the block and head and also did more body bashing. I tried all week to remove the two stuck head studs. I tried heating, cooling, fancy penetrating sprays, vibration, impact and swearing. Nothing worked. in the end I machined up a little guide and cut the studs off half an inch above the deck and drilled them out. There was some damage to the threads but I already have some damaged threads that will need fixing either with stepped studs or threaded inserts.

IMG_4218_1 Head stud drill guide.

I also gave the block and head another go in the electrolytic bath but this time I used washing soda instead of baking soda. It seemed to work a little better and seemed cleaner although that could just be due to their being less rust this time. I removed the core plugs from the head and vigorous shaking got all the loose rust flakes out. You don’t want them floating about blocking the radiator or water ways.

IMG_4220_1 Head rust flakes.

The block and head came up great in the end. I also used a borrowed bore gauge to measure the bore more accurately. The gauge scale read 2.249 inches. Measuring the gauge with verniers gave me 57.4 mm and 57.37 mm (I have two sets – neither great) which is 2.260 and 2.259 so I am pretty sure the block is bored for +60 thou as I first though.

IMG_4236_1 Clean head and block.

It’s interesting to note this is an early block than one for a 1937 car. It has the screw in end caps.

I also did more body work although this is really starting to hurt my shoulders. I think since I come home from a totally sedentary job (every so often I move the mouse at work to keep ME awake, let alone my computer). So I have to be careful I don’t over do it. I redid some of the split welds, four in all, each a few inches long. I am slowly getting it all smooth. The pictures all look the same now but it really is getting better!

IMG_4233_1 Smooth.

Joss popped over and helped me get the rear axle on the chassis. I was going to attach the hubs and so on but I found I don’t have the correct sized cotter pins that hold the spring pins in place so I need to order those. You can’t attach anything else until they are in place. I’ll order some from the spares department this week. We also noticed that the floor wasn’t running parallel with the wooden template I am using for the firewall. It seems the middle of the floor was a little high because my wooden supports that run under the floor and across the chassis rails were about 3/16ths too high. I am not sure how I didn’t notice before. I trimmed them and made sure the floor now sat level with the help of a piece of angle iron across the rear of the chassis as a reference line.

IMG_4238_1 Firewall template.

You can see how the firewall is now further forward meaning it makes up the back of the passenger seat (OK, there will be a little padding). Later I will glue sticks radially from the board out to the touch the inside of the aluminium skin then I can draw a curve between them and use that as the template for cutting the steel.

The other thing I did was buy a new AMR 300 blower. As I had previously found out there are actually two variants. One, the more common, used on Subaru and the other used on Mitsubishi cars. I had the latter so the pulley I bought wouldn’t fit it. Below you can see the differences between the two blowers. I believe they use the same rotors but I haven’t pulled them apart to find out. Probably best to leave them alone!

The Mitsi one is on the left with the more common Subaru on the right.

IMG_4224_1 IMG_4225_1 IMG_4226_1

IMG_4227_1 IMG_4228_1 IMG_4229_1

The Mitsubishi is labelled: AISIN ?D 119400 AMR300. Serial number is 9D0260.

The Subaru one is labelled: AISIN 14408 ???61 (I think it’s 14408KA861) ARM 300. Serial number on it is 406821.

The ? is where the labels are scraped and a bit hard to read. The Sharpie marker gives a good ideal of scale.

3 Responses to “New AMR300 and other progress.”

  1. Ritchie Wilson Says:

    I see you are using gas welding on the aluminium.
    Is this better than, say, TIG?
    Thanks for your reply (years ago) about the DYCO drill switch.
    I also was given a pile of “On the Road” magazines. Parallel Lives!

  2. admin Says:

    I think for this sort of thing it is better. I’ve never had the chance to do TIG welding but I believe the welds it produces are very hard. With oxy-acetylene welding the metal ends up annealed and very soft. Hammering it all afterwards not only gets it smooth it re-hardens it again. I guess gas welding is the traditional way of doing it.

  3. shaun Says:

    KInda random, but do you still have that mitsubishi amr300? I have been trying to source a replacement for my 87 minicab supercharged van after mine ran dry on oil and self destructed. Been a real struggle to find a supercharger, or whole engine just to get the supercharger as the mitsubishi units are very rare compared to the subaru counterparts.

    If you didnt use it, is there any chance you would be willing to sell the mitsubishi unit? Very serious, and willing to pay to get my van back on the road finally.

    email me, or text or call if you are in the states 503 410 1915

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