Jeff's 3.8 and 4.2 Projects.

Here is a few pictures of some of the engine building tools that I have been making for this project.
A connecting rod balancing scale, stroke/height measurement tool, ring squarer, connecting rod vice, rod bolt stretch gauge, magnetic deck bridge and a tdc stop.





 
Machined the block main counter bores today. I used the same endmill and program that I used on the main caps. The tool is a 1/2" endmill with a small radius ground on the bottom edge making it somewhat into a bullnose endmill. I didn't want a sharp edge in the bottom of the counterbore. Since I had the block set up and dialed in on the mill I decided to use a flycutter with a cemented carbide tool to clean up the oil pan rails, they just needed a few thousands taken off of them. After all this was done I re-tapped all of the holes in the block and then used a countersink to break the edges off all the holes. Just need to make the alignment bushings and then make them fit properly.





 
Made the steel bushings for the main caps today. I used either 1030 or 1045 mild steel, not sure of what it was on the shelf. They have 0.080" wall thickness, are 0.400" tall and have a bit of clearance for the studs on the inner diameter.

 
Made the steel bushings for the main caps today. I used either 1030 or 1045 mild steel, not sure of what it was on the shelf. They have 0.080" wall thickness, are 0.400" tall and have a bit of clearance for the studs on the inner diameter.



Are the main bearing caps also counter bored to accept these alignment bushings ?

David
 
I love this. Will you make kits for attaching the blower to a split port?

It might be a possibility down the road if I make some revisions to it. Hard to say at this point.

This evening I trial fitted the bushings to the block and main caps and they all fit perfectly with a just a bit of tapping from the rubber mallet which was intended. All that time using a dial indicator to dial in each hole on both the caps and block was worth it after all. Defiantly a worthwhile yet time consuming upgrade that should pay dividends in the future.
 
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So...Double roller timing chains. Let's have a go at it shall we. I know SCU and Morana both have them available so if you need one get one from them, but I like a challenge and saving money so let's see where this goes.

I did some research and it seems that Morana might be using a 351w timing set as a basis for his kit so I started with that and ordered a timing set from Rock Auto. First thing I did was bore the crank sprocket in the lathe to fit the 3.8/4.3 crank. Not much had to be cut out of it to make it fit. After that it became apparent to me that the fuel pump eccentric hole would be a problem with the overbore to fit the 3.8 camshaft diameter and would need to be plugged before boring. I made a plug for it and then TIG welded it place with a few tack welds and then ground them down a touch.

After the boring I was able to mock it up on the engine to see how it fit up. As was somewhat expected, the overall chain length was too short, by about 2 links. The 351W timing chain has 58 links, I needed 60. I found one available that should fit the 351W sprockets and correct chain length in a GM part number. I ordered it tonight so I guess we will see in about a week how it fits and if I will need the tensioner or not.


Plugged but before welding.


Getting ready to bore it out a small amount.


Dammit, two links short.

Still left to do assuming that the chain fits properly is to cut a 5mm keyway in the camshaft sprocket and machine the sprocket and spacers to fit as well as figure out what Torrington thrust bearing I need to buy and then machine the retaining plate to fit it.
 
My ARP main studs showed up today, they are of the usual Ford 2.3 L4 variety. I was somewhat anxious about receiving them as I had expected that there might be issues with the stud girdle that I made for it ahead of time and sure enough there was. I suppose hindsight is 20/20...rookie mistakes abound.

I made the counterbores too big (was thinking about bolts + socket width at the time) which only really affects the first main cap on the girdle as the counterbores on the other 3 caps are shallow enough for me to cut them to size without any real issue. I am going to weld up the counterbored holes on the girdle for the first main cap and then counterbore all the stud holes to fit the ARP studs and nuts because as you can see, the studs are not long enough to clear the girdle as it currently exists.

I was hoping to avoid milling the main caps but with the current design of the girdle it is apparent that it is inevitable so I am going to cut around 0.300" off of them while maintaining a raised center section (the factory step in the middle) as the girdle is already machined to accept it and I like the idea of the girdle locking into the main caps with it. Also, I am about 0.200" of clearance short between the oil pan and the top of the front studs short and these changes should remedy it. I will cut the studs slightly if needed if the above mods do not give enough clearance.

I suspect that I will end up fabricating a custom oil pan for it eventually because why not at this point, but that is not for the near future.

I would prefer to have the studs bolted down with the girdle on top with more bolts but it is not to be, the girdle will be on top of the caps with the nuts on the studs torqued down. I like the idea of having steel main cap bushings for the caps/block for alignment and strength while the aluminum girdle adds to it and absorbs harmonics and vibrations. I suppose time will tell if this combo works out long term or not....

 
I milled the tops of the main caps for clearance today as well as deepen the counterbores in the main cap girdle.
I also did some work to the double roller timing set camshaft sprocket. I broached a new keyway, faced off the excess "snout" material to size and recut the oil channels in it.

Hopefully the bottom end all fits together nicely now. Will find out later today.











EDIT: The shorter main caps gave me the extra clearance I was looking for and the slots lock into the girdle firmly however I will need to clearance the girdle for the rod bolts further now, at least the crank still clears. I also need to remove about 0.200" from the front 2 studs so the oil pan will seal. I will do that in the lathe rather than a grinder.
 
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Some interesting concepts. I like the idea of a double roller but $300 US per is $500 CAD landed or more and pretty painful to the wallet.
 
Some interesting concepts. I like the idea of a double roller but $300 US per is $500 CAD landed or more and pretty painful to the wallet.

I agree. If this works out I will probably have less than $100 CAD total spent in parts so it was worth a chance. I can't justify it paying for one of those either however considering the amount of R&D work, parts and the considerable labour time it takes the prices are actually quite fair for them but there are better places to spend your money inside the engine and the stock replacements seem to be very reliable. If I can't make this one work I will just grab a stock one like I was originally planning to.
 
I think that you are using the wrong chain to start with bud. I bought one of Morana's first chains from a member here and it was not a 351 chain. It appeared to be an 82-87 3.8 chain with a hub that he machined and attached to the cam gear with 4 bolts.
 
I think that you are using the wrong chain to start with bud. I bought one of Morana's first chains from a member here and it was not a 351 chain. It appeared to be an 82-87 3.8 chain with a hub that he machined and attached to the cam gear with 4 bolts.

Might be, I will find out Friday when the new chain arrives. He is at least using the crank gear from a Summit set so he is likely using the cam gear as well. The part numbers match on the crank gears. SUM-G6620R-B

https://bit.ly/2YjrEOJ https://www.summitracing.com/int/parts/sum-g6620r-b/overview/

This is why I ended up buying a cheap 351W set to modify as a test. I think my setup is basically done expect for the missing chain which I think will be 60 links. I don't yet know if I need the tensioner yet or not. If the chain works I will add a roller thrust bearing as well.

Thank you for the photo. I might try that method next if things go sideways on this version. I can see why he did it that way. It eliminates the problem of the fuel pump eccentric hole. It needs to be filled/plugged before boring the hole to fit the correct cam size.
 
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Hmm. He may have changed what he is using because the one I bought (pictured) had a large hole with no key way slot and a round machined hub that was bolted to the gear. It also didn't have multiple crank slots either.
 
After modifying the main caps as mentioned above I ran into the problem of the rods hitting the girdle so I did a bit of clearancing on that.

My test/replacement timing chain came today for the roller setup, a day early at that which was nice. Kudos to Rock Auto.

and....it fits! It seems just snug enough when installing. There is very minimal play w/o the tensioner and absolutely none with the tensioner installed but coiled (not even actuated yet, the pin is still in it). It may not even need the tensioner but as I had bought a new one I tested it with it anyway.





Note: It came with that black link from the factory, I did nothing to the chain other that taking out of the box.

I ordered the roller thrust bearing today from McMaster-Carr. Just a small bit of machining involved on the spacer to make that fit. It should be in next week.

I am still a very long way from actually testing this combo but all signs point to it working out so far for minimal $ spent not counting my time machining it to fit.

On the downside today, I decided to fix up a couple of welds on my oil pan as their was a couple of questionable ones that I wanted to be 100% sure of. Long story short, I applied too much heat to too cool of an oil pan and induced thermal stress/cracks in a couple of places. Re-welded it somewhat but I don't trust it. It's relegated to mock-up duty now. It's not worth the risk of using it so I will either get a factory replacement or fabricate one of higher capacity with baffles etc later on or maybe I will cut it off just below the flange and build and weld up a new one from there. It's around $175 CAD or so to buy a new replacement and considerably cheaper just to buy some aluminum and then have me cut and weld a better one up so I guess my decision is probably already made for me I suppose.
 
Made up another tool today. Not sure if I will ever use it but I had a piece of scrap aluminum around of the correct size so I figured why not? It is for adding radial gas ports in the top piston rings on a 3.8/4.2. Of course the tiny drill bit broke but I can deal with that when back at work on Monday and finish drilling it then.

The groove locks into the second piston ring groove for positioning. I can also use it as a piston holding fixture in a vice.


 
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