AMC 360 Stroker (383) for Donzi

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I have a few 383's out there in AMC cars but now I finally get to build one for a Full Size Jeep!
To get to 383 cubic inches, it requires a 4.155" bore and 3.53" stroke

Here is the block all cleaned and ready to go.
IMG_4319 by Rick Jones, on Flickr

I love part numbers with "RD" or "X" in them. "RD" means Research and Development but a "X" could mean anything.
IMG_4315 by Rick Jones, on Flickr

This block is a late Jeep block. The extra core plugs in the back were added to the drawing 2-5-1979
IMG_4316 by Rick Jones, on Flickr

I Sonic check the block before and after boring. I check several places until I find the thinnist spots.
IMG_4318 by Rick Jones, on Flickr

This is nice thick block. The absolute thinnist spot is .110". This block could have been bored out to the 401 bore of 4.165" and would have still been ok. I go to 4.155" because it is a standard size and to stay on the safe side.
IMG_4320 by Rick Jones, on Flickr

Here is the purdy crankshaft. I had it off-set ground to a 2" journal with a 3.53" stroke.
IMG_4321 by Rick Jones, on Flickr

On the performance engines I drill out the main bearing feed holes to match the 5/16" oil feed hole below it.
IMG_4322 by Rick Jones, on Flickr

[JPSwapMohn]

I don't think I have seen/heard of an AMC 383, that's cool!
Did the crank start as a 360 unit, or an unobtainable 401 crank?

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Originally Posted by JPSwapMohn

I don't think I have seen/heard of an AMC 383, that's cool!
Did the crank start as a 360 unit, or an unobtainable 401 crank?

360 crank off-set ground to 3.53" stroke with a 2" journal diameter machined to fit the 6" 6cyl chevy stroker connecting rods
http://www.ifsja.org/forums/vb/showthread.php?t=110924

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Connecting rods: The stock AMC 360 connecting rod width is .997” and is not machined down narrower at the crank end like the 401 and other makes rods. I was not able to find an off-the-shelf aftermarket 6” connecting rod to fit a 2” journal that is wide enough for the 360 crank. I called Scat in hopes of getting a set of sbc rods before they machined the big end down. The piston end of the sbc rod is wide enough. I told them what I was trying to do with the wider 360 crank and they recommended using a 6” stroker rod from a GM 250 6 cylinder application. This rod is 1.050” wide, made for a 2” journal.
3831 by Rick Jones, on Flickr

I order custom pistons to my specs to fit the pin in the bore size that I want, with the desired piston pin height.

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This picture shows where I added the extra oil drain back holes in the valley area. I drill them and angle them towards the cam at each lobe. The ones through the valley are 3/16" with a chamfer and the ones at the back of the block are 5/16" and I make a little oil trough to help direct the oil to the holes. This block will get the interanl oil line as well.
383 by Rick Jones, on Flickr
3832 by Rick Jones, on Flickr

[rang-a-stang]

Originally Posted by SC/397

This picture shows where I added the extra oil drain back holes in the valley area. I drill them and angle them towards the cam at each lobe. The ones through the valley are 3/16" with a chamfer and the ones at the back of the block are 5/16" and I make a little oil trough to help direct the oil to the holes. This block will get the internal oil line as well.

Do you do this to all your blocks? (wondering if I should plan on doing it with a mild 401 build)

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I don't do it to all of the 304 or 360 builds if they are basically stock rebuilds.
I do it on all 390s, 401's and performance 360's assuming the engine will be ran hard. Basically, I am just trying to help get the oil back to the pan as fast as possible.

[rang-a-stang]

Originally Posted by SC/397

I Sonic check the block before and after boring. I check several places until I find the thinnist spots.
IMG_4318 by Rick Jones, on Flickr

Sorry for the pesky questions: Is your thickness Meter probe the standard one that comes with the meter or is it specifically for measuring curved surfaces?

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It has the smaller diameter head so that I can get a more accurate measurement. It is within .008" so, it is pleanty close enough.
Again, I move it around to get the very smallest reading at all of the positions. Even at the .110" measurement (.102" adjusted), I can move the probe 1/4" in any direction and the reading will go up to .140"+.

[wiley-moeracing]

not picking on your ideas, but why would you drill drain holes that dump oil on the camshaft? you are creating windage by dumping oil on cam as it spins and not letting it drain back into the pan faster? I have always drilled or enlarged the drain holes in front and back to get the oil down into the pan as fast as possible without creating drag on the reciprocating masses when doing my race motors. Again not saying your wrong or right just asking if there is a better idea?

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Originally Posted by wiley-moeracing

not picking on your ideas, but why would you drill drain holes that dump oil on the camshaft? you are creating windage by dumping oil on cam as it spins and not letting it drain back into the pan faster? I have always drilled or enlarged the drain holes in front and back to get the oil down into the pan as fast as possible without creating drag on the reciprocating masses when doing my race motors. Again not saying your wrong or right just asking if there is a better idea?

I can't take any credit for the idea. Drag racers and road racers have been doing that for years. I saw it in a magazine and thought it was a good idea. If you relied on the rear center drain back hole for oil return, the oil goes right on the cam anyway. Rather than having the oil pool up in the little pockets, I would rather have it drain back in. I guess it would be hard to measure how much, if any, drag it would be on the cam at any given rpm for a street engine.
017 by Rick Jones, on Flickr

[Donzi]

Looks good! Can’t wait to see the progress and get it into the Jeep!

[mattmopar440]

will you have it dyno tested ??? just wondering what it will make compared to a 401

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Originally Posted by mattmopar440

will you have it dyno tested ??? just wondering what it will make compared to a 401

No plans to dyno this one. The first one I built made 406HP and 424#/ft of torque but it was a different recipe. The first one had 10.4:1 compression ratio with a Torker intake, Summit 8601 cam and a 750 Holley.
This one will have 9.3ish compression ratio, Air Gap intake and a Comp 270H cam. There is talk of fuel injection once Donzi gets ahold of it.

It is screwed up because of the photosucket problem but there is more information on that build in here:
http://www.ifsja.org/forums/vb/showthread.php?t=110924

Here is a picture of the connecting rods that we are using.
IMG_4333 by Rick Jones, on Flickr

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Timing Set rework as usual. This one is in a Milodon box but it is made by SA Gear. I am not a fan of the big slots in font so, I will braze them shut.
IMG_4417 by Rick Jones, on Flickr
IMG_4420 by Rick Jones, on Flickr

Comp Cam. The oil slot is pretty close but, I will move it over to be centered with oil feed hole in the cam.
IMG_4416 by Rick Jones, on Flickr
IMG_4418(1) by Rick Jones, on Flickr
IMG_4421 by Rick Jones, on Flickr
IMG_4419 by Rick Jones, on Flickr

[Gladiator4x4]

Awesome writeup again sc. I read your other writeup on 401 crank in a 360 block but cannot see the pics. Dumb question time can you put stock 401 parts in a overbored 360 block and get a 401 or is the deck height lower on a 360 block?

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Originally Posted by Gladiator4x4

Awesome writeup again sc. I read your other writeup on 401 crank in a 360 block but cannot see the pics. Dumb question time can you put stock 401 parts in a overbored 360 block and get a 401 or is the deck height lower on a 360 block?

The deck height is the same on all the V8's after 1970 so, the 360 and 401 have the same deck height. The stroke is longer and the journals are bigger on the 401 crank so, you have to use the 401 rods. The pistons would be built to order to fit the 401 piston pin size, the bore size tat you specify, the pin height that you specfy, and the compression ratio that you specify.

The short answer is yes you could put the 401 crank, rods and pistons in a 360 block but it would require a bore of 4.165". It has been done before.
- Not recommended unless you sonic check the block to make sure it can handle that big of bore.

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Making a little more progress...
Bultear doesn't sell matching Distributor Gear sets any more so I will be trying a pair from MSD.
camgear by Rick Jones, on Flickr

I chase all of the threads in the entire engine with a tap. This takes a little time but has saved me headaches in the long run. It still amazes me how much crud gets jambed in the tapped holes. This is the timing cover. I would have never gotten a bolt in these two holes without cleaning them out first. Alot of it is old RTV.
tap1 by Rick Jones, on Flickr
tap2 by Rick Jones, on Flickr

[johnsonic]

I love the detail in these writeups SC - keep'em coming & thanks for doing it!

[Ristow]

msd gears are (were?) made by the same company that made the OEM,i was told by randy at PAS years ago.