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AAR project

marksmopars

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Interesting note on engine parts, this engine was prepped before and it appears that the crank and rods were shot peened and balanced. It includes 5 rods with stock 340 rod numbers and 3 rods with 318 stock numbers. Physically the rods look identical except for the number? They were balanced as a set including hand engraved numbers on the rods.
I’m hoping someone out there might know more about this as it’s my nature to want to know. 😊
 

Xcudame

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The factory 340 rods from 68-72 where 2899496 and the pin was bushed by the factory. In 71, the 360 used 3418645 rods that did not have pin bushings. The 318 used the 340 "496" rods, but didn't have pin bushings. In 73 the 318, 340 and 360 used the "645" rods. From what I can tell, there is no significant difference from the "496" rods and "645" rods other than the factory pin bushings in the 340 engines. The "645" rods have enough material to easily and safely install pin bushings.
 

Challenger RTA

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As Xcudame posted. I knew the answers. But I had to look it up to be sure. Just busy. As far as the rods. If you old use rods They can be magnifluxed and reconditioned. I think that is the course of action to take. Thanks Xcudame!
 

marksmopars

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The factory 340 rods from 68-72 where 2899496 and the pin was bushed by the factory. In 71, the 360 used 3418645 rods that did not have pin bushings. The 318 used the 340 "496" rods, but didn't have pin bushings. In 73 the 318, 340 and 360 used the "645" rods. From what I can tell, there is no significant difference from the "496" rods and "645" rods other than the factory pin bushings in the 340 engines. The "645" rods have enough material to easily and safely install pin bushings.
I should be specific that this engine has 5 rods numbered 2899496 and 3 numbered 3418645, should have said this earlier, fyi.
 

Xcudame

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I figured that is what you meant because those are the two that look so much a like. The earlier 318 (and 273) connecting rods are slimmer and there would be no way to balance them the same as a 340 rod.
 

marksmopars

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Just received the rocker arm assemblies for the T/A motor, was not included with the car. Most everything else was and these look awesome! Just what we needed to finish the motor for this beast. 😊

IMG_4600.jpeg
 

marksmopars

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Word from my machinist is couple weeks to completion. I need to ask for thoughts on six pac carberator controls. The factory six pac runs the front and rear totally on vacuum. The set up I received is totally manual with the outboards set to hit full open when the primary is same.

I have the factory set up on my t/a and am very familiar with the vacuum set up. The manual set up for the Aar actually looks sound, but I’ve never run one so I’m hesitant to run as is. I have parts needed to return to factory set up.

Any thoughts on this? If it was yours what would you do? Note that I’ve just gotten the chassis onto a homemade frame jig and ordered needed frame rails and crossmember. I have an opportunity to take the engine frame the machine shop to an engine Dino, after which it will sit until I finish the body.
 

don selleck

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I would try it mechanical, I usually run mechanical secondaries on four barrels, I like the instant response when there tuned right. Vacuum that I've ran seems to have that momentary hesitation. If you don't like how it responds you could always change it back later. would like to see the mechanical set up they did, I thought about making mine mechanical, doesn't seem to look to be much of an effort to change it, to that.
 

fastmark

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It is not intended to run mechanical secondaries. They have no accelerator pumps so they will have a flat spot guaranteed. I restore and tune six packs and have owned and raced one since 1976. All you have to do is get the diaphragm spring kit and you can adjust them to where they come in faster and will not bog. Mopar made a setup that had mechanical secondaries but the outboards had accelerator pumps.
 

marksmopars

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I would try it mechanical, I usually run mechanical secondaries on four barrels, I like the instant response when there tuned right. Vacuum that I've ran seems to have that momentary hesitation. If you don't like how it responds you could always change it back later. would like to see the mechanical set up they did, I thought about making mine mechanical, doesn't seem to look to be much of an effort to change it, to that.

IMG_4637.jpeg
 

don selleck

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It is not intended to run mechanical secondaries. They have no accelerator pumps so they will have a flat spot guaranteed. I restore and tune six packs and have owned and raced one since 1976. All you have to do is get the diaphragm spring kit and you can adjust them to where they come in faster and will not bog. Mopar made a setup that had mechanical secondaries but the outboards had accelerator pumps.
makes sense, would starve for fuel upon kickdown, then catch up as venturi effects kick in. but would like to see how much.
 
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