DuPuis Family Cobra Build

[EppyGA]

Good idea, gonna pick a nit though. It will be align bored.

 

[Ted]

Good idea, gonna pick a nit though. It will be align bored.

Fair enough, but when I tell the machine shop "Line bored" they know what I mean.

Assuming the machine shop says the block looks good, I'm figuring pretty standard fare for it:

- Overbore (will have to buy the pistons first, of course)
- Align/line bored
- Deck the block
- New freeze plugs
- Let the machine shop install the cam bearings
- Hot tanked (that'll probably be part of the inspection anyway, along with probably a magnaflux)

What to do with the main caps, that's the real question I think. They're a known weak area, so I think that ARP bolts/studs are a bare minimum requirement. If I reuse the aft sump (which I'm thinking I will) I'll need to make sure the bolts/studs I use have provisions for the support on the #3 main cap.

When I read up on splayed caps, it seems that those who use them have great things to say about their ability to improve the durability of stock blocks. Those who haven't used them say they don't think they help. I'll see what the machine shop has to say, and then also get an idea of what it costs to add them.

 

[Ted]

Well, I called up the machine shop I used before and the phone number has been disconnected. The building was in bad shape, the owner had died a bit under a year ago (I actually never saw the owner), and the guy who was always there when I went by was also old and didn't seem in the best of health, although he'd hired a kid towards the end of when I picked up the 9N motor. It wouldn't surprise me if the estate decided to just close down the shop. I imagine that the property was worth something. Sad to see a machine shop that did good work shut down.

There's another machine shop a lot closer to my office that looks to have a similar decrepit building and the guy who answer the phone seemed similarly challenged with talking to people. Those seem to be the marks of a shop that does decent work and the Google reviews mostly say good work, just slow. So I'll probably bring this block by and see what he says.

 

[PaulS]

Well, I called up the machine shop I used before and the phone number has been disconnected. The building was in bad shape, the owner had died a bit under a year ago (I actually never saw the owner), and the guy who was always there when I went by was also old and didn't seem in the best of health, although he'd hired a kid towards the end of when I picked up the 9N motor. It wouldn't surprise me if the estate decided to just close down the shop. I imagine that the property was worth something. Sad to see a machine shop that did good work shut down.

There's another machine shop a lot closer to my office that looks to have a similar decrepit building and the guy who answer the phone seemed similarly challenged with talking to people. Those seem to be the marks of a shop that does decent work and the Google reviews mostly say good work, just slow. So I'll probably bring this block by and see what he says.

Machinists can be a cantankerous lot. My suggestion is to just tell him what you want, listen to what he has to say and decide if it will work. Most are usually busy and spend a lot of time being told how to do stuff by people who have no clue, that's what makes them cantankerous, mostly.

 

[Ted]

Machinists can be a cantankerous lot. My suggestion is to just tell him what you want, listen to what he has to say and decide if it will work. Most are usually busy and spend a lot of time being told how to do stuff by people who have no clue, that's what makes them cantankerous, mostly.

Yeah, that's essentially my plan. Take him the block, say what I want to do, ask his opinion on whether the block is worth doing or some of the items I'm thinking about with it and get his opinion on those. Then I'll decide if I want to push forward or if I want to go with a short block.

Doing the math, I do think I can still save some money by going this route. Of course it's not worth it if I have a result that will grenade, hence why I want to make sure this does seem like a good candidate and get the machinist's opinion on it.

Transmission wise, I ordered this book:

http://www.5speeds.com/cart/index.php?route=product/product&path=25_28&product_id=33

This guy has some really good videos on YouTube and has been doing these transmissions since around the time I was born.

One thing I've determined is that I will be going with bronze shifter fork bushings and a bronze shifter cup. These items are normally nylon. The nylon bushings work just fine, but because I specifically like to feel what the transmission is doing, the bronze will be more to my liking. Yes they will transmit more vibrations and noises - that's the point.

I also think I'll want to go with bronze synchros. The alternate is carbon fiber, and sort of similarly, the bronze is a bit tougher and from what I can figure makes the transmission a bit notchier. I'll be interested in seeing what he has in the book specifically for other ideas.

I've been saying for a while now that what I ought to do is pull the rear end and get started working on that, and that remains true. But it's probably a good thing I waited since I've now decided that I want 3.55s instead of 3.73s to match the T-5 I'll be doing (with different ratios than the TKO I was originally planning). So maybe over the weekend I'll pull the rear end, but really I've got other stuff to keep pushing forward on. I could argue that I should build up the T5 first since if I have some issue there that makes me go another route, I could end back up at 3.73s.

 

[Ted]

Few positive things this evening.

First one is that I pulled the starter off and, as I had thought, it's a lightweight unit. The thing weighs in at under 8 lbs (at least according to my bathroom scale). So, that's one thing I don't have to buy! I'll just use it.

Other one is that while browsing Summit Racing I found this closeout deal on Ford Performance aluminum flywheels. At 25% off I figured that was a deal worth snagging:

https://www.summitracing.com/parts/FMS-M6375A302AB

I had a bit of reservations on the fact that it's the 28 oz external balance flywheel and I don't have a rotating assembly yet, but after looking at the various rotating assembly and short block options, I'm confident that won't be an issue - I'll probably end up with 28 oz anyway. So now that just makes that decision.

I've found some lightweight balancers as well and need to look into those, maybe look for a deal there.

 

[Ted]

Just dropped off the block. The machine shop seems to have the right qualities. Guy is quirky, shop is a hole in the wall with the building in disrepair, engines, cranks, components, all over the place. We chatted a bit and I like the guy, so hopefully this works out.

His general thought is he wouldn't be scared of the block, but obviously needs a line bore and needs to get checked. So the first step is just checking the block to make sure it's good, then we go from there. He said it'd take a good 3-4 weeks, so it sounds like they work on the same timeline as the other machine shop I used previously. If it goes well, then I'll order the rotating assembly bits.

I also asked about the main caps and if he thought I should do anything with those. He said no, just check those along with the block, and some ARP bolts/studs would be a good idea but that's as far as he'd go.

He confirmed he has torque plates for 302s for the bore/hone, and he can do all of that in-house. The line bore he has to send it out for is all. So, good progress there.

 

[Zeldman]

The machine shop seems to have the right qualities. Guy is quirky, shop is a hole in the wall with the building in disrepair, engines, cranks, components, all over the place.

I haven't seen a good machine shop look any different.!!

 

[Ted]

I haven't seen a good machine shop look any different.!!

Exactly. If a machine shop looks like a shiny building with shiny new machines and everything neatly organized, then I probably don't want to go there.

 

[Zeldman]

A friend of mine, his FIL has a machine shop that has the newest machines in it. All computer controlled, all isolated and in air conditioned and air tight in their little inside buildings which everything is just obscenely clean.

And he has all girls working for him. There really isn't anything to running it. Just plug in the program, put the material in, close the door and hit the run switch.

If I remember right, his shop builds some certain little parts for the giant sea going oil tankers, which is the major part of his business. He does mostly contract work and doesn't do cranks or blocks.

 

[Ted]

It's important to know the difference between a machine shop and an automotive machine shop. In this case I'm referring to an automotive machine shop.

When talking about a machine shop not for engines but for making widgets and things, that's a different story entirely and I am much more interested in seeing those shops cleaner.

I'm not an HR person by any stretch, but there are certain personality types that lend themselves to particular jobs. Once you learn those you learn what to look for.

 

[-KLB-]

Actually, in some markets, finding a machine shop to do one off work, and not production runs is getting tougher. A relative actually takes some of his small, precision machining jobs to a ratty place in a worn out historical building that looks like it might have been an Art Deco car dealership back in the day, with lots of engine blocks that can be be seen through the front window, and they have about a 15 foot long crankshaft mounted out front as their signage.

Says they take on jobs, including single part count CNC that other shops won’t touch.

 

[-KLB-]

I'm not an HR person by any stretch, but there are certain personality types that lend themselves to particular jobs. Once you learn those you learn what to look for.

Try hiring for a position where you want one particular silo of deep technical IT knowledge and strong ability to communicate with upper management. These just don’t seem to exist together, and when they do, they are outside the rate we are looking to pay. So guessing which compromise between the two skill sets is going to work best just sux.

 

[Ted]

Try hiring for a position where you want one particular silo of deep technical IT knowledge and strong ability to communicate with upper management. These just don’t seem to exist together, and when they do, they are outside the rate we are looking to pay. So guessing which compromise between the two skill sets is going to work best just sux.

My group is in a similar predicament. We look for engineers who are also able to be customer facing with both engineering counterparts and management within our company and at our customers.

For me it's a fantastic fit, but finding people who have that right blend is a challenge.

 

[Zeldman]

Actually, in some markets, finding a machine shop to do one off work, and not production runs is getting tougher. A relative actually takes some of his small, precision machining jobs to a ratty place in a worn out historical building that looks like it might have been an Art Deco car dealership back in the day, with lots of engine blocks that can be be seen through the front window, and they have about a 15 foot long crankshaft mounted out front as their signage.

Says they take on jobs, including single part count CNC that other shops won’t touch.

Sounds like the machine shop in my home town in Texas, including the long crank out front. If memory serves me right, the building was once a Studebaker dealership.

 

[-KLB-]

Sounds like the machine shop in my home town in Texas, including the long crank out front. If memory serves me right, the building was once a Studebaker dealership.

In Bryan?

 

[NealRomeoGolf]

Exactly. If a machine shop looks like a shiny building with shiny new machines and everything neatly organized, then I probably don't want to go there.

Then don’t visit the machine shop that makes current D4 parts.

 

[Zeldman]

In Bryan?

Yep, In Bryan.

 

[Ted]

Didn't end up making any progress on the Cobra this weekend. Aside from having fun with the family I chopped down about 4 acres worth of brush, made some trips to get various necessities for the homestead, and then fired up the dozer to clear some tree stumps from the runway.

My 25% off aluminum flywheel showed up yesterday, and as advertised it's <12 lbs. Very light weight - exactly what I wanted. I'm looking forward to having that in the engine!

I'm debating whether I want to wait on rebuilding the rear end until after the transmission or not. I'm generally figuring that if I stick with the stock T-5 gears, I'll want to go with 3.55s. If I upgrade the main gear set in the transmission, then I'll want the 3.73s I have now (although I might get different physical gears anyway, not knowing the brand of these). However either way the 5th gear will remain the asme at 0.68. That would lend itself better to 3.55s than 3.73s. The real difference is the 1st gear - 3.35 for stock T-5 gears and 2.95 (roughly) for upgraded gears. So I haven't ordered any parts there, but I also haven't pulled that rear end.

With my book showing up tomorrow I figure I'll read it, tear the T-5 the rest of the way apart, and see what there is to determine there before ordering the parts I need, and deciding what exactly those parts will be. So now more of a research phase again.

The steering rack is en route and should be arriving on Thursday according to the USPS. That'll be a full week en route from Pennsylvania to here - insanely slow delivery time (they don't call it snail mail for nothing) but it's a good enough deal and it's not like I'm in a rush.

So really, the next steps I need to work on are finishing disassembling the transmission, pulling the rear end at some point and disassembling it, and then ordering some parts for those. Additionally I can pull the pedalbox and the emergency brake handle from the parts car anytime I want. I might try to get those out next weekend.

 

[Craig]

A friend of mine, his FIL has a machine shop that has the newest machines in it. All computer controlled, all isolated and in air conditioned and air tight in their little inside buildings which everything is just obscenely clean.

And he has all girls working for him. There really isn't anything to running it. Just plug in the program, put the material in, close the door and hit the run switch.

His shop would’nt happen to be in Casper, Wyoming?

 

[Zeldman]

His shop would’nt happen to be in Casper, Wyoming?

Somewhere in the Houston metroplex area. That is why everything I air conditioned....

 

[Craig]

Somewhere in the Houston metroplex area. That is why everything I air conditioned....

Kinda funny, as I have an online acquaintance that has an all CNC shop, with almost all female employees, but he's in Casper.

Was in and out of several of the oilfield machine shops down there when I was growing up.

 

[Ted]

For those who haven't seen it, the Ford v. Ferrari trailer has been released:

Now this gives me motivation to get the car driving by November 15th. It's an achievable goal...

 

[Ted]

Today I picked up the parts I need for converting the rear axle to appropriate spec for the Cobra. The biggest thing this does is gets me the correct length 5-lug axles, but it also gets me the "Cobra" brakes which are a larger diameter and will make the brakes look more right and also give better braking than the stock SN95 brakes would by a hair. I'm actually just putting in standard rotors for now that aren't slotted or cross-drilled. That's what I have, they're brand new.

I started reading through the transmission rebuild book last night and it is a good book with some useful information that will at least help with disassembly. I need to go buy a few new tools at Harbor Freight, which I'll do either later today or tomorrow - probably tomorrow. Not likely to get things disassembled further tonight anyway.

My goal for now through the end of the weekend is to get the rear end and transmission fully apart and determine what I need to order so I can then get parts coming. The limited slip seems to work, but there is a question as to whether or not it actually meets spec, and then I also want to see the condition of everything before ordering the full kit. My plan is to go with Ford Performance parts for the rear end.

Depending on how progress goes, I might also pull some of the remaining parts out of the parts car that I need - specifically pedal box and hand brake handle.

For the T5, I will probably order the rebuild kit from the same guy who wrote the book since he sells kits. But I do want to order the bronze shift fork bushings as well as the bronze shifter cup bushing since those will help to improve the "feel", which is a big thing for me.

I also ordered the vacuum power brake kit for the car. This uses a stock power brake booster and master cylinder, with some relocated master cylinder reservoirs and includes a cut-out for the frame to make it all fit. Most people go with hydroboost, but since I'm not using a power steering pump, I think this is a better way to go.

 

[Sac Arrow]

Ted's famous words as a violent snap sends his shift lever through the windshield.

"*#&%$ Harbor Freight transmission tools!"

 

[Ted]

Ted's famous words as a violent snap sends his shift lever through the windshield.

"*#&%$ Harbor Freight transmission tools!"

Yeah, maybe I should buy a better torque wrench...

Actually the only parts I'm looking at buying from them for this are bearing splitters and race drivers. I've been driving races for years with a punch and a brass hammer just fine, but I figured I'm old enough to start doing it the "right" way.

 

[SoonerAviator]

Amazingly, I went to HF to buy a cheap 1/2” rice torque wrench and they were sold out. Lowe’s actually had one of their electronic versions for less money as it turned out. I was working on automotive stuff that wasn’t particularly sensitive, so being within 5ft-lbs was good enough as opposed to getting expensive torque wrenches.

 

[gkainz]

Amazingly, I went to HF to buy a cheap 1/2” rice torque wrench and they were sold out. Lowe’s actually had one of their electronic versions for less money as it turned out. I was working on automotive stuff that wasn’t particularly sensitive, so being within 5ft-lbs was good enough as opposed to getting expensive torque wrenches.

HF torque wrenches aren’t all that bad. When my craftsman that I had from the late 70s died, a HF replaces it and does ok.

 

[Ted]

Amazingly, I went to HF to buy a cheap 1/2” rice torque wrench and they were sold out. Lowe’s actually had one of their electronic versions for less money as it turned out. I was working on automotive stuff that wasn’t particularly sensitive, so being within 5ft-lbs was good enough as opposed to getting expensive torque wrenches.

I spent a large portion of my wrenching career nary touching a torque wrench, and never having an issue where it actually mattered.

Harbor Freight has come up in quality a lot, and is quickly replacing what Craftsman used to be. Someone who came by to buy things off of the parts car is a mechanic at a local Chevy dealer. His toolbox contained HF tools. When I was wrenching, it was all Snap-On or Mac.

 

[PaulS]

The tough part about those trannies and rear ends is making sure everything is shimmed and aligned correctly. Depending on who made them, a subscription to a factory manual service might be worth the price.

 

[Ted]

Oh, and since we all like pictures...

My replacement steering rack arrived today. This is the manual rack by design, and this one has a chromed center section. It supposedly has about 1,000 miles on it and I believe it. It's very tight.

It seems to have standard length tie rods and no extenders on it (note, this is where I ran into trouble before). So my plan is to try to learn more about the specific need for the extenders before I do anything there. I got the polyurethane rack bushings out of the other rack and into this one, though. So now I just need to get the proper steering knuckle.

 

[Ted]

The tough part about those trannies and rear ends is making sure everything is shimmed and aligned correctly. Depending on who made them, a subscription to a factory manual service might be worth the price.

Very good point. In this case, it seems the required information from Borg Warner and Ford (for the T5 and 8.8 rear end, respectively) are available free online:

http://www.tremec.com/anexos/TRSM-T5-0510-R1_173.pdf

https://performanceparts.ford.com/download/instructionsheets/FORDINSTSHTM-4209-8.PDF

I may print out both of those just for good measure, though...

 

[asicer]

For those who haven't seen it, the Ford v. Ferrari trailer has been released:

Now this gives me motivation to get the car driving by November 15th. It's an achievable goal...

I saw that during game 2 of the NBA finals. I may have to get me a Cobra now. Or maybe not if the movie tanks.

 

[SoonerAviator]

I spent a large portion of my wrenching career nary touching a torque wrench, and never having an issue where it actually mattered.

Harbor Freight has come up in quality a lot, and is quickly replacing what Craftsman used to be. Someone who came by to buy things off of the parts car is a mechanic at a local Chevy dealer. His toolbox contained HF tools. When I was wrenching, it was all Snap-On or Mac.

Agreed, I’ve got a few HF tools in my chest as well. Mostly impact sockets from their Pittsburgh Professional line and a few air tools that rarely get used but were dirt cheap for a one-off project. They’re pretty reasonable for tarps as well. I’ll be picking up their US General 41” tool chest top/bottom boxes before year end too. Those boxes are still the best value out there, built solid and good bearing slides.

 

[Ted]

I saw that during game 2 of the NBA finals. I may have to get me a Cobra now. Or maybe not if the movie tanks.

A friend of mine suggested that Factory Five will be selling a lot of cars based on the previews of this movie alone. He may be right. Of course the movie is about the GT40 not the Cobra, but both being iconic Carroll Shelby cars and GT40 replicas costing significantly more, I think the Cobra will be more popular.

Agreed, I’ve got a few HF tools in my chest as well. Mostly impact sockets from their Pittsburgh Professional line and a few air tools that rarely get used but were dirt cheap for a one-off project. They’re pretty reasonable for tarps as well. I’ll be picking up their US General 41” tool chest top/bottom boxes before year end too. Those boxes are still the best value out there, built solid and good bearing slides.

I haven't bought any HF air tools but pretty much all power tools I've bought from them have been garbage, so I've been reluctant to buy any air tools from them. For air I tend to go high quality - my air ratchets are Ingersoll, so is my 60 gallon air compressor. I figure those are buy once, buy for life things. But a lot of their sockets and ratchets I find are respectable quality.

 

[Ted]

Got a response back from the person I bought the rack from. He said that it shouldn't require the spacers as it should be the correct width for the car. Once I get it installed I'll confirm that, but that'll make things easier if so. I need to get that knuckle so it'll probably be a week or two before I get the rack actually installed.

 

[SoonerAviator]

A friend of mine suggested that Factory Five will be selling a lot of cars based on the previews of this movie alone. He may be right. Of course the movie is about the GT40 not the Cobra, but both being iconic Carroll Shelby cars and GT40 replicas costing significantly more, I think the Cobra will be more popular.



I haven't bought any HF air tools but pretty much all power tools I've bought from them have been garbage, so I've been reluctant to buy any air tools from them. For air I tend to go high quality - my air ratchets are Ingersoll, so is my 60 gallon air compressor. I figure those are buy once, buy for life things. But a lot of their sockets and ratchets I find are respectable quality.

I think the air tools I had were a HPLV paint gun (works great), cutoff wheel, and a die grinder, nothing too technical. I have heard great things about their 1/2” Earthquake impact driver, but I have a nice AirCat impact already. I wouldn’t buy their larger air compressors, but they’re probably okay for occasional use.

 

[Ted]

I think the air tools I had were a HPLV paint gun (works great), cutoff wheel, and a die grinder, nothing too technical. I have heard great things about their 1/2” Earthquake impact driver, but I have a nice AirCat impact already. I wouldn’t buy their larger air compressors, but they’re probably okay for occasional use.

After I typed that I realized I had to take that back. I have their air rivet gun (for pop rivets). So far I'd say it works ok. Not great, but does the job. I have herd good things about their HVLP spray gun and intend to buy that when it comes time to paint the thing.

Something that has occurred to me is that if I feel like it I could also start on some of the body work, at least getting the seams sanded down. But it's not like I'm hurting for things to do on the car at the moment.

 

[SCCutler]

...keep 'em coming.

Seems to me (FWIW) that you're going to have a crap-ton of torque per the weight of the car, so I'd go for the taller gear ratio. It's not like 3.55 is a long-legged highway gear, anyway.

 

[Ted]

...keep 'em coming.

Seems to me (FWIW) that you're going to have a crap-ton of torque per the weight of the car, so I'd go for the taller gear ratio. It's not like 3.55 is a long-legged highway gear, anyway.

Something to remember is that I'm building the engine in a manner that cruising/running at under 2k RPM might not work too great. I don't want 5th gear to be effectively unusable at the speeds I'll actually be driving the car. Around here, highway is 65-85 MPH. Also if I do end up tracking the car, 3.73s or 3.55s will be much better all around for speeds. The Isky cam that I'm currently eyeing for this build is advertised as a 2,000-6,000 RPM cam, and my guess is that the idle will lope a good bit such that 2,000 RPM will be where the engine will start to run right, and 3,000 RPM is where it'll start coming into its own.