2.0L Duratec Rebuild

[JohnCh]

The Raceco silencer has steadily increased in volume over the years and was clearly due for a rebuild. Disassembly showed the packing in the back 2/3 was in near perfect shape, but grew progressively worse towards the inlet end, with a several inch long section completely burned away. Raceco covers the core tube with a very fine mesh which adds life to the packing material, but which also burns away over time. Replacing the packing,but not the core tube when needed, simply ensures that the replacement packing won't have a long life. In the case of my silencer, the core tube was shot and replacement was mandatory.

 

 

 

As long as everything was apart, a minor cosmetic restoration was undertaken to clean away grunge from years of exhaust leaks and to sand down the road rash from the grit and gravel sprayed from the right front tire. As you can see from the before and after photos, it still won't pass for new, but looks far more presentable.

 

 

 

 

 

Thanks to very tight tolerances, reassembly was a bit fiddly, but it's back together and ready to go on the car once the engine and exhaust manifold are reinstalled. Unfortunately I'm still a few months away from those events and even further from hearing how it sounds.

 

-John

[JohnCh]

The head was dropped off at the shop about 3 weeks ago with a target of mid-December completion. This timing would allow me to reassemble and install the engine over my break the last half of December, but delays with the different machine shop doing the short block work have thrown that timetable out the window. The good news is that my spot there finally opened up last week and yesterday I learned they can address the damage in #1 mentioned earlier with a minor overbore. Although they said 0.25mm would do it, the Omega pistons come in a 0.5mm overbore, which means I'm going big and increasing displacement by a whopping 22.9cc.

 

Raceline is pulling together the package of parts that includes the pistons, rings, o-rings/intake seals for the Jenvey throttle bodies, and the various replacement items needed to rebuild the wet sump. Hopefully pistons aren't held up in customs and I can have the car back on the road by late January/early February. That's a perfect time of year in the PNW to break in a new engine in a se7en and do road mapping (note to those who are sarcastically challenged: yes, that was sarcasm).

 

Also an update on the journal damage pictured in post #2. Before dropping the short block off at the machine shop, I took a closer look at those specific bearings and noted a very subtle matching stain on the bottom shell which I missed during my initial inspection. The theory is that this staining resulted from the engine sitting for an indeterminate length of time before purchase. The machine shop said it's uncommon, but they've seen it before and don't have concerns, although to be fair they still haven't measured it to be 100% certain. I've asked them to do this before keying the crank.

 

-John

[JohnCh]

Not much progress lately thanks to delays at the machine shop followed by even longer delays waiting for Raceline to ship the pistons. I like Raceline and appreciate the advice they offer via phone, but as long as I've been ordering from them (since 2003) getting things shipped has always been an exercise in frustration. Once the machine shop confirmed the piston size needed on 12/5, I called Raceline the next morning to place the order. Before taking my credit card number, they wanted to put together the package to establish an accurate shipping weight. This process took them until the 11th. Based on conversations, I expected it to go out within a couple of days, however, it didn’t ship until the 23rd. Fortunately there were no issues in customs and the pistons are now in the hands of the machine shop.

 

Both SBD and Raceline sell the Omeg pistons, with SBD being a little cheaper (458 GBP vs. 475 GBP). However, I opted to go with Raceline since their tech support was a known quantity and there were a few minor maintenance items I still needed to order from them that would effectively ship for free if added to the order. Upon opening the box of pistons, I was a bit surprised to find a spec sheet from SBD included, and even more surprised to see the tops of the pistons stamped with both Omega and SBD branding. I guess there is no mystery about who provided Omega with the specs.

 

 

 

I've been unmotivated to so some of the remaining small jobs, so decided to address something unrelated that has bothered me for a while. The standard Westfield boot box is a small item that drops down through the boot opening and is removable to assist working on the back end of the car. The problem with this design is that its dimensions are dictated by the size of that opening rather than by the space available in the tub. That space flares out as it approaches the fuel tank, mirroring the rake of the bulkhead in front, and the body to the rear. Wanting to take advantage of that space, I fabricated a custom boot box out of aluminum sheet that has a removable floor for maintenance, but holds roughly double the volume.

 

It looked fine when new as shown in the photo, but over the years, that nasty, hard to clean, black oxidation that afflicts bare aluminum had firmly taken hold and would transfer onto anything left in the boot that slid against the sides. Given how I drive that car, anything in the boot is subject to a lot of sliding and thus a lot of black streaks. Sucking up the weight hit (~0.5 lb) I added some carpet normally used to cover subwoofer boxes. It looks good, is unbacked and much lighter than normal carpet, and it sticks to velcro meaning I could use that as the attachment method. We'll see how it holds up.

 

 

 

-John

[xcarguy]

The carpet looks very nice...and that’s a mighty fine looking piston.

[JohnCh]

Yes they are. In fact if they had shown up when expected, I would have been tempted to hang them from the tree BTW I meant to include weight measurements before. I haven't bothered to disassemble a factory piston/rod assembly, but the combined weight is 942 grams. A K1 rod with fasteners comes in at 518 grams and an Omega piston with rings and pin comes in at 410 grams for a total assembled weight of 928 grams.

 

-John

[JohnCh]

The engine rebuild gods have been messing with me lately and I need to vent. This will be long post with no photos to hold your interest, so I’m breaking it into two posts.

 

After doing some research on bearings used in the UK for hot Duratecs and their US availability, I settled on Daido bearings sourced through Mountune USA. They had the various sizes (std, +1, -1) in stock and although not cheap, it seemed a painless option. My machine shop, however, uses the high performance lines from Clevite and ACL in their race builds (not Duratecs – and yes, this parenthetical comment is meant as foreshadowing) and was suspect of Daido since they had zero experience with the brand. They preferred to source the bearings from their suppliers. Given I didn’t want any finger pointing if a bearing-related problem arose down the road, I agreed.

 

Fast forward to the start of this month when the shop called me to say their suppliers can’t get the bearings. We agreed to revert back to my original plan, and I placed an order with Mountune. The bearings arrived at the machine shop last week. On Tuesday they called to say (1) the main bearings are too tight and we need the smaller size, and (2) the rod bearings are wrong. They have a tang, but the rods have no provision for that locating mechanism.

 

The size issue wasn’t a surprise. It seems that Ford has reasonably wide specs on the Duratec which can require fiddling with bearings at time of rebuild, hence the reason it’s important to go with a bearing that comes in various sizes. After investigating the rod bearing issue I realized either my reading comprehension or my attention to details is poor. As Croc will point out, it’s probably a combination of both. The Daido main bearings fit both the Duratec and the Ecoboost derivative. The rod bearings, however, are Ecoboost only. They don’t make the tang-less version for the Duratec.

 

End Part 1

 

-John

[JohnCh]

Begin Part 2

 

This is where things really turned south and my propensity for swearing hit overdrive. Given I am building an engine that is safe to 8500 rpm, I don’t want to use OE replacement quality bearings. Yes, they might be fine, but after all the trouble and expense, this isn’t an area where I want to take chances. Looking at race/high performance/really special -- or however else you want to characterize them – rod bearings available in the US, I hit road blocks. Clevite makes them, but only in the standard size. If, like the main bearings, my engine needs under/over sized then I’d be stuck. ACL makes them in various sizes, but the standard size is out of stock and it is at least 2-3 weeks to get them. Longer if the factory needs to make another run. Apparently demand is low.

 

King Bearings make the rod bearings in the XP range and they are in stock in the US. I spoke with both SBD and Raceline in the UK this morning. SBD sells King and said they’re fine, but added the Mahle Motorsport bearings at twice the price are the best quality. Ordering the Mahles from them is about $230 with shipping. Because they are in a blister pack, they are unreturnable if a different size is required. That would mean more cost and more international shipping delays. Peter at Raceline also uses the Mahle Motorsport bearings, but said he knows a lot of people who use the King bearings and has never heard of an issue, so thinks they’re fine. He only sticks with the Mahle because that’s what he knows.

 

I then went through the runaround of finding a King Bearing supplier who would sell me a set. Some of the places I called only sell to shops. Others don’t deal with Duratecs and don’t want to special order, and finally some just don’t seem to answer their phone. I finally found a shop that was happy to take my money, but they are not allowed to ship to a location other than the billing address. That means more delays getting the bearings to the shop and more delays getting the car back on the road.

 

I hope there isn't a part 3 to this story...

 

-John

[Anker]

Hmmmm. At some point maybe sooner rather than later I will have to rebuild my Xflow 1700 Superspeed. I am going to spend this winter catching up on maintenance and replacing simple things like ignition, carb caskets, installing a catch can for the oil breather, etc.. Then drive for a season, mostly autocrossing, and then decide whether it is time for a rebuild and whether it will be just the head or the whole engine. Sounds like sourcing parts is the biggest issue. I don't like the idea of having to order several sizes of oversize bearings and using one.

 

One of the reasons whuy I like the Ford Kent is because it is used for Formula Ford, but there are so many Caterham-specific parts in my engine (the entire head, cam shaft, pistons, ...) that I suspect I'll end up with the same issues. Not something to look forward to.

 

Good luck, and please keep up with documenting the story!

[xcarguy]

........now I know WHY it costs soooooo much money to build these engines.

 

John, allow me to help you out......:cuss:@#$^% :banghead: #$%@@*& :cuss:

[Croc]

After investigating the rod bearing issue I realized either my reading comprehension or my attention to details is poor. As Croc will point out, it’s probably a combination of both.

 

No I would not point that out. I just would point out that it is past 12pm where you are and there some very nice vineyards within 10 minute drive of your home that would sell you a lovely delicious bottle of red or white to pour a glass or three and breathe...

 

 

SBD sells King and said they’re fine, but added the Mahle Motorsport bearings at twice the price are the best quality.

 

For the record, I think you are worth it. Your Westfield demands the best. Think of your Westfield as your high maintenance trophy wife. She demands the most expensive everytime - shoes, kitchen, renovations, clothes, dogs, minions, etc.

 

Well it works for me, which is probably why I live in a small 1 bedroom hovel in a flood zone.

 

 

 

 

Being serious for a moment - bit surprising that it is so difficult to get the right size bearings with quality suppliers. I mean, how hard could it be.

[JohnCh]

Anker, I wouldn't worry about the crossflow. The SuperSprint spec is a well known formula for those engines and unlike the Duratec, the crossflow was designed to be rebuilt rather than thrown away when old and tired.

 

Yeah, I was really surprised by the difficulty. Initially I assumed the machine shop was being lazy, but after multiple Internet searches (I have the blisters on my fingertips to prove it), calls to Clevite/Mahle, ACL, King, and various Focus tuning shops, I realized that wasn't the case. Duratec tuning in the US seems to focus on forced induction rather than spinning at high rpms, and people seem happy with the OE spec. It just seems to me that bearings aren't an area where you should hope they're good enough.

 

The excursion to a winery sounds like a good idea, but a side trip to a place where they sell something stronger sounds better

 

-John

[JohnCh]

I'm still waiting for the rod bearings to arrive. I'll ping the dealer again to see if they can get an update from King, but I had expected them to be here by now after placing the order with Priority Mail shipping on the 23rd.

 

One area I've been kicking around for the build is intake length. Longer pushes the torque peak down, shorter pushes it higher in the rev range, and at some length you hit the sweet spot. That perfect compromise which smooths out the torque curve and maximizes the area beneath it. The default for Duratecs with Jenvey TBs seems to be 90mm, but I've been curious what would happen to the shape of the curve when going longer or shorter, particularly given the other work done to my engine. There are rumors that longer than 90mm produces better results, but I've yet to see actual numbers to back that up. Given longer runners require the air filter to stick further out of the bonnet, which in turn requires a larger hole in said bonnet, I'd rather some hard data before pulling out the saw.

 

Although Emerald makes adjustable velocity stacks with a range of 60-130mm (more info here) that are perfect for my needs, the 45mm size required for my TBs have been shown as out of stock for a very, very long time. After speaking with Dave I learned that unless they can find a new supplier willing to do them for a reasonable price, they won't do another run. It sounds like the original shop underestimated the effort, and at the new production cost the retail price becomes, in Dave's words, "silly." Luckily for me, he was able to find a lightly used set in their inventory, so the order was placed this morning.

 

 

-John

[Sean]

[ATTACH=CONFIG]16546[/ATTACH]

 

Good golly. Within a year or so, if not now, one could have a simple shape such as intake trumpets 3D-printed in any number of materials, with cost being the only limiting factor. And cost is dropping rapidly. I have recently seen 3D-printed parts in titanium, aluminum, and inconel that had a drop-dead gorgeous finish and were dimensionally accurate for all but the most demanding applications. Maybe you could just get some made? For trial sets, all you'd need is a fuel-resistant material. Or maybe this would end up being more costly - I don't know. Just throwing it out there...

[JohnCh]

Hi Sean, I think you missed the part where I wrote that Dave found a lightly used set on the shelves that I bought this morning They were only 100GBP, so not expensive. Although even at the new price of 135GBP for the set, they are a good deal if you want to experiment.

 

-John

[Croc]

Inconel is an austenitic nickel-chromium-based superalloy

 

 

I had to ask someone over breakfast this morning! :seeya:

[fastg]

The most common use of Inconel is turbo mounting bolts, it has crazy heat properties and turbo mounting bolts live in a very inhospitable place. I have user then on a couple of turbo cars with success. I think in the F1 world they 3D print exhaust system using it.

 

https://www.extreme-bolt.com/products-inconel-bolts.html

Graham

[Anker]

They could easily be made on my 3D printer in ABS or Nylon, both of which are fuel resistant and heat resistant enough for trumpets. I can't print in metal (yet).

 

Anker

[JohnCh]

The rod bearings turned up yesterday. However, thanks to flooding and mudslides impacting my commute, I'm working from home this week and probably won't have an opportunity to drop them off at the shop until early next week. Yes, it's wet. Even for Seattle.

 

More good news; the head arrived a couple of hours ago. Steve said it was in great shape and he didn't see the need to do further porting than his original job 13 years ago. However, he did re-profile the backside of the valves this time, which in his experience can help airflow as much as blending the seats. The laundry list of work included:

 

Clean head and valves

Surface head

Machine seats and reface valves

Modify valves with performance upgrades

Valve seal set

Install new cams, set valve lash to provided specs, assemble

 

-John

[xcarguy]

John, I’ll be very interested to see what numbers you come with using those adjustable stacks.

[JohnCh]

Given Murphy seems to rule my life with his eponymous Law, 90mm will probably prove to be the optimal length, but I still want to see the numbers.

 

-John