4G63/G63B parts differences...

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PrimeIsFine
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4G63/G63B parts differences...

Post by PrimeIsFine »

I've looked over the swap info on the site, but I had a couple of questions for clarification.

I have a 1G 4G63 (non-turbo) from a DSM and a wideblock G63B from a D50. The plan is to combine the two for a wideblock DOHC 4G63, which will eventually bolt up to the B2600 bellhousing/tranny that I have collected to go with it.

My main question pertains to the cranks. I'm under the impression that there is no difference between non-turbo/turbo cranks. Is this correct? And if so, the crank is also the same as the one in the truck motor, correct? Trying to figure out which one to use (if it matters) with the aftermarket rods and pistons.

Any other suggestions on parts I should use from one to the other? So far I plan to keep the bridged main caps from the DOHC motor. And I should use the oil pump cover from the DOHC motor, correct?
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Last edited by PrimeIsFine on Fri Feb 11, 2011 4:27 pm, edited 1 time in total.
fuel
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Post by fuel »

There is no difference between a turbo or non-turbo crank, but there is a difference between SOHC and DOHC cranks - the front stub where the cambelt sprocket and crank pulley attaches is longer on the DOHC motor.

So use the D50 wideblock block with the DOHC crank and DOHC front timing cover/oil pump. If you use the bridged main bearing caps from the DOHC motor there's a high chance your D50 sump will no longer fit.
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Post by DJpowerHaus »

I've used SOHC (4G64) cranks in DOHC setups just fine. I really doubt the crank is different in any way.
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PrimeIsFine
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Post by PrimeIsFine »

So regardless of crank, do I need to use the oil pump cover from the DOHC?
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Last edited by PrimeIsFine on Fri Feb 11, 2011 4:27 pm, edited 1 time in total.
PrimeIsFine
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Post by PrimeIsFine »

So, I got productive today and tore into both motors, now I have two giant collections of parts and a couple of bare blocks. In case any one is interested, I got out a set of calipers and measured both cranks, which are identical in all dimensions (including the front stub length).

I did find something that made me scratch my head in regards to the oil pump. As shown in the picture below (the lighting isn't great, but I think it gets the point across), I have both oil pump covers side by side. The DOHC is on the left and the SOHC on the right. On the SOHC cover it has a shaft that spins attached to the oil pump cover, but on the DOHC it does not. In both motors, it has an identical shaft on the other side of the motor, but the shaft slides into the oil pump cover and isn't attached. So the SOHC motor has 2 shafts and the DOHC has one shaft. First off, what are these supposed to be for? They appear to be some sort of pickup shaft, but they aren't even close to the bottom of the motor. I've never seen anything like it. Second, why is there 2 in the SOHC and one in the DOHC? I'm planning to use the SOHC pickup and oil pan, since the motor is going in a truck, but I'm not sure if there is a reason I should use only one shaft with the DOHC head. Thanks for the help in advance.

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Last edited by PrimeIsFine on Fri Feb 11, 2011 4:27 pm, edited 1 time in total.
Gentleman Rogue
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Post by Gentleman Rogue »

thats the balance shaft- it eliminates excess vibrations coming from the motor. it does this simply for comfort and doesnt help the engine at all. many people eliminate this(as i did). your oil pressure will increase slightly, and lots of guys like not having another little belt in the timing cover that can go bad and take everything out in the timing cover. heres a good how-to with pics:

http://www.vfaq.com/mods/balance-shafts.html
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Post by jeffball610 »

It appears that someone has already performed a balance shaft (silent shaft) elimination on your DOHC motor. They likely left the front (exhaust side) shaft in to block the oil holes. This is a lazy way to do it, but it works.

I would be interested to see how the bridged caps transfer over to the SOHC engine. You'll definitely want to line hone the main bearings (obviously) but I would like to see the end result. Depending on your end power goals, there may not be a need to use the bridged caps. I bet you could make a 400hp motor without the caps using stock 1G rods and some 2G pistons. Simple, effective, and cheap.
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PrimeIsFine
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Post by PrimeIsFine »

So what were the purpose of these shafts from the factory? "Balance shaft" would seem rather obvious, but I don't see how they're really attached to anything that they balance. What's the deal?

As for the bridged caps, I've read (on here I believe) that they're not much use until past 600 hp. But, since I'm planning on doing machine work anyways and already have them, I'd just as soon use them. The main concern I have right now is if they fit inside the truck pan. I'll probably start bolting things together tomorrow, do you have anything specific you want to see?

As for the build path of the motor, the current plan is to use the stock crank, Eagle H-beam rods and Wiseco pistons for the bottom end. As for the head, what Slowboy calls Stage III work on the head and Comp Cams (272 duration). Not sure what turbo I'll use yet, but I'm still a ways off on that one. Trying to focus on the motor/tranny basics right now.

I'm going for about 450 hp, which should be pretty easy with the setup I'm planning. I'm really hard on vehicles though, so I like to build pretty bulletproof. Eventually, all of this will go in a Mazda B-series pickup that I've been building for a few years. So far I've built a full mandrel bent frame with adjustable suspension, X-brace, etc. Currently in the process of sectioning the body and chopping the top. Not trying to make a drag (or drift) car out of it, but have something with a little power that I can hammer around corners in. I've had alot of mini trucks and always wanted a V8 in one, but I figured this is much cooler and alot more rare.

My best friend has a 9 second Mustang that we run around in and he always gives me shit about build good looking vehicles, but nothing that is fast (and Mazda trucks had 86 hp from the factory). So, I figured this will be fun to maybe crank the boost up on and get some drag radials and go hand him his ass. Or at least scare him a little.
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Last edited by PrimeIsFine on Fri Feb 11, 2011 4:27 pm, edited 1 time in total.
PrimeIsFine
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Post by PrimeIsFine »

Well, I got it all mocked up and bolted together. I'm going to build a cart for the engine/tranny and then it's ready for the move. After I get a place and settled in, I'll tear back into it and start the actual running version. Thanks for the help guys.

And I have a couple sets of 1G rods/pistons, a 1G crank and a narrow pattern 4G63 block if anyone is interested. Along with some random pulleys and accessories. I guess I'll post an ad in the for sale area, otherwise they are going to the recycler.

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