Tear Down and Rebuild of My R400 Duratec Engine

[aerobod - near CYYC]

I will check all the chambers for consistency when I remove the camshafts before the valve removal for the port work, I haven't rotated the cams on the refurbished head yet, so just picked the only chamber with all valves closed for the quick check. I may use the conventional pipette and perspex plate method, but the putty method seemed to be an easier and less messy method with good results that I think can be better than 0.5cc variance and is also the only practical method for the piston dome volume measurements without fully fitting and torquing down the head.

I wanted to do the quick check to determine what my compression ratio and needed head gasket was going to be before finalising the order with Raceline, so that I could calculate the dynamic compression ratio when I know the cam specs for either the RLD250M or RLD270M cams that Chris was going to get for me.

At the moment I have calculated the dynamic compression ratio at 1000m altitude for the D-TEC35 cams as 9.0:1 (68 degree ABDC inlet closing) and the D-TEC45 cams as 8.4:1 (75 degrees). With wanting to set the rev limit to 8,200RPM for engine longevity, I'm tending towards the earlier closing profile with slightly better low-end torque and more optimum 9.0:1 CR that the RLD250M should have in supposedly being close to the D-TEC35, but will see what Chris has to say.

[aerobod - near CYYC]

I spent an hour with Chris at Raceline going through all my spec, he is certainly a top chap in terms of getting to the right build spec and making sure all the details are covered.

We went through the cam details for the RLD250M, RLD270M and RLD280M specs and decided that the RLD250M is a better fit to both my altitude and rev limit, making peak power at close to 8000RPM. The other cams are more peaky and surprisingly have lower lift at TDC with a slightly higher ultimate lift, but they also really need oversized valves and a rev limit beyond my expected 8200RPM to get the most from them. By staying with the RLD250M cams I will have a balanced and known engine config and although they use 11.7:1 CR pistons in that build, my 12.5:1 CR pistons will almost match the same dynamic CR due to my altitude.

Chris also recommended using the Ford OEM (not aftermarket) main and head bolts, especially with an over-bored engine. They have seen liner distortion with the ARP bolts due to the very high torque specs and the Ford bolts are good on engines up to 300bhp and 9000RPM. My re-bore was also done with the main bearing cradle bolts bolts torqued to the Ford spec. They do recommend ARP connecting rod bolts, though, which I already have.

They will also send me the base fueling maps for their engine builds, so I can scale and pre-load my MBE maps to be close to final spec, but allow initial piston ring break-in before putting the car on the dynamometer. They will also supply port-matched (to standard 2.0 head ports) 48mm DTH throttle bodies, which will reduce my fettling on the intake side.

The clutch components I will use will be Helix, combined with the Raceline 8 1/2" lightweight flywheel, which was specifically designed to avoid the Caterham steel billet flywheel warpage that they had seen on a supercharged Caterham driveline they built some years ago.

Overall I'm ready to order the config now, around CAD$6,600 (£4,000) with shipping and duty for the Raceline parts that when added to my existing block machining, head, pistons and connecting rods costs of $3,281 (£1,970) should give me a nicely upgraded engine that is both reliable and capable of 250bhp at sea-level.

[aerobod - near CYYC]

After a bit of research Raceline had to do to ensure the correct Helix clutch friction plate is obtained, the parts order from the UK is now complete and hopefully should be shipped next week.

The big palaver this week was trying to source the main bearings. I wanted to go with the upgraded Mahle Clevite "H" series bearings, but couldn't find a supplier with them in stock until a company in Illinois showed them as available. Unfortunately after placing my order, they messaged me yesterday to say their last set had already been sold and Mahle is not manufacturing them any more. I looked at King bearings, but have read too much about them not being as dimensionally accurate as the Clevite bearings.

A bit more research shows that quite a few Mazda MZR turbo engines have been built to 500bhp using the standard Clevite main bearings (MS2245A), so I decided to order them. I did manage to source the upgraded big-end Clevite CB1840H bearings, though. Supposedly the upgraded big-ends and standard main bearings are a common and suitable combination for higher power Duratecs.

[7 wonders of the world]

I run stock Ford OE mains with ACL race big ends... never seen any issues with the mains when stripped.

 

 

 

[aerobod - near CYYC]

1 hour ago, 7 wonders of the world said:

I run stock Ford OE mains with ACL race big ends... never seen any issues with the mains when stripped.

 

 

 

Thanks for that info Neil, it aligns with what I was finding from other builds, too. Puts my mind at rest that upgraded mains are not needed, perhaps the reason Mahle have discontinued them due to lack of demand.

[aerobod - near CYYC]

The bulk of my parts shipped from Raceline are now almost here - just paid the customs clearance and GST (Canadian VAT) charges of $397 (£232). With the whole package weighing 28kg, it cost £275 to ship from Shropshire to Calgary, but I saved £780 in VAT, that more than covered the shipping and import charges. Just need them to release it for pickup now, don't want them leaving it on the doorstep if I'm not in......

[7 wonders of the world]

Christmas has come early then....... 

[aerobod - near CYYC]

All parts now ready to go, next step is to get the crank, flywheel and clutch cover balanced.

[Seabea23]

Thanks for posting your engine rebuild story, really interesting. 

[John Vine]

14 hours ago, aerobod - near CYYC said:

All parts now ready to go...

A veritable cornucopia, James!   Fascinating story.  I'm looking forward to the next episode.

JV

[aerobod - near CYYC]

I did a careful measurement of all the piston and connecting rod weights today, triple checking results and matching the parts to give the closest total mass per cylinder and matching the opposing cylinders (1&3, 2&4) to give the closest balance weights when rotational mass and 50% of the reciprocating mass is added together. Quite pleased that everything is within a few tenths of a gram:

Edited December 7, 2023 by aerobod - near CYYC

[StevehS3]

Wonderful attention to detail, James. It will be a superb engine.

[Seabea23]

This is why I am a club member, a superb article.

[aerobod - near CYYC]

While I'm still waiting for my parts that are out for balance and not wanting to do battle at the shops with the hordes today (Christmas Eve afternoon works for my Christmas shopping), I thought I would make a start on remapping the ECU parameters that need to change.

First off is to ensure I've updated the relevant comments in the ECU file to ensure I don't mix then up. With the MBE ECU files and Easimap, there is a good comparison function. I've decided to call my maps R500A maps, as the car is meant to be close to an R500, fettled by Aerobod (the 'A" bit 🙂 ), also using my latest R400 map as a comparison:

The next thing to do is adjust the limiters to make use of the new forged internals, the 'A' listings are for the R500A, the 'B' listing are for the R400:

Then I need to adjust for the new injectors and airflow changes. There are several factors that I need to consider:

- Increased airflow, especially at the top end due to Jenvey throttle bodies and higher lift and duration cams. My estimate is that air flows and power outputs will be similar up to 4500RPM or so (as reviewed on various R400 and R500 dyno plots), so I will assume similar air mass flow from 1000-4500RPM. After 4500RPM both the volumetric efficiency and torque curve move up for the R500. Analysing my old R400 logs for fuel flow, I think VE peaks at 93% with a lower peak BMEP at my 1250m altitude compared with sea level, I think the new engine will peak at about 105% VE at just over 7000RPM. I therefore will add 1% fuel at every 250RPM from 4500-7000RPM until it reaches 12% additional fuel, then keep that amount until the red line.

- Scaling due to the swap from "Blue" Bosch 0280156162 injectors with a 172.4g/min flow rate to "Green" Bosch injectors with a 310.0g/min flow rate. This means a 0.556 scaling factor, plus additional latency (that is handled as an add-on by the ECU).

- A different offset / latency parameter for the Green injector opening.

The best parameters I have found for the injectors is in this chart:

Using this chart, I can update the voltage vs injector opening latency values:

The fuel maps are now scaled with the 0.556 factor applied everywhere, followed by the ramp up to 12% additional fuel above 4500RPM due to better VE:

After the main 3D fuel map has been modified, the only other maps that need to be altered are for starting purposes, as other parameters such as baro pressure, air and coolant temps, etc are all used as percentage modifiers, as opposed to absolute millisecond values:

This now gives me a reasonable map that is relevant to the new engine, although I still have to adjust the TPS parameters once the engine is back in the car and everything is connected, before I can start the engine. I'm also going to do a lot of other cross referancing to any other maps I can find to further validate the values I have entered into the fuel maps so far. At this point I'm not going to modify the ignition maps until I can get the car on to the dyno in the spring.

 

Edited December 24, 2023 by aerobod - near CYYC

[aerobod - near CYYC]

From an injector change perspective from ‘Blue’ to ‘Green’, the injector plug also changes from Uscar to Jetronic. I decided to use an adapter at the moment instead of cutting off the plug and replacing with a new one. Unfortunately Jetronic plugs are a step backwards from a sealing perspective, as they don’t have one whereas the Uscar plugs do.

I ordered these:

[aerobod - near CYYC]

I have also assembled a set of tools (besides the normal spanners, sockets, torque wrenches, feeler gauges, etc) that will be needed for engine assembly:

- Cam Timing Disk - for basic cam advance and retard reference

- Duratec Crankshaft and Cam Timing Tool - used for basic timing to ensure cranshaft and cams are in the reference position

- Metric Dial Gauge with Magnetic Stand - for precise cam and TDC measurement

- Metric Vernier Calipers - for parts sizing confirmation

- Valve Spring Compressor set

- Die Grinder and Burr set - for head port fettling

- Harmonic Balancer Holding Tool - to enable easy torquing of the crankshaft bolt to 400Nm or so, without needing the flywheel and a lock in place

- Spigot Bearing Fitting Tool - a turned down piece of aluminium to allow tapping the input shaft spigot bearing in to place

- Piston Ring Grinding Tool - for ring gap sizing

- Piston Ring Compressor - a machined ring to gently fit the rings

- Plasti Gauge - for big-end and main bearing clearance confirmation

- Digital Scale to weight match reciprocating parts

- Throttle Body Synchrometer - for air flow balance matching

- Angle Torquing Gauge - for precise torquing of bolts that require a jointing torque plus angle

- Portable Assembly Table

- Magnetic Parts Holder - keep those unruly nuts and bolts in a known place

- Last but not least, an Engine Stand sanctioned by SWMBO to be brought inside the nice warm, bright and clean utility room, so I have a temperature controlled environment to do the assembly.

Edited December 24, 2023 by aerobod - near CYYC

[John Vine]

Fascinating stuff, James!  Keep the updates coming (even if I don't understand everything -- especially the mapping bit).

JV

[PhilT]

Really enjoying following this! Thanks for documenting and sharing.

[aerobod - near CYYC]

My "Man in a Shed" came through with the balancing today. The crankshaft on it's own was already balanced to within 25g.mm, as was the flywheel and harmonic balancer. The Clutch cover plate was about 120g.mm out, so had about 1g of material removed from the outer edge. Total rotating assembly first order balance is now within 25g.mm, which makes it accurate to an ISO G 1 level for the 27kg assembly:

The drilled area for clutch cover plate balancing:

[aerobod - near CYYC]

I have created a sub-assembly preparation list for items to be carried out on the components before the full assembly can take place, which is well documented in the relevant Ford and Cosworth assembly documents:

Edited December 28, 2023 by aerobod - near CYYC

[aerobod - near CYYC]

While disassembling my dry sump for cleaning, one worrying issue is that 2 of the button head baffle screws were only finger tight, not backed out by more than a fraction of a thread, but no torque left on them at all. Definitely will add some blue thread locker on them when they are put back in:

[aerobod - near CYYC]

Today I disassembled the refurbished head after measuring valve clearances. Some of the tappets are sizes that are no longer available (there used to be steps down to 0.02mm, but current part numbers are generally 0.04mm). Here are the current clearances with 0.25mm inlet and 0.30mm exhaust spec, the new clearances and tappet sizes needed for the 18 current Ford part numbers are then derived (with an aim of 0.25 +0.02/-0.01mm, with the tolerance spec being +/-0.03mm):

It doesn’t look like many of the tappets can be reused and Kent recommend new tappets anyway, so I will test fit the new cams with the closest tappets I have and re-measure before buying the new tappets, but the head needs to be fitted and fully torqued to determine the clearances accurately.

I have also realized that although the head casting number of the refurbished head is the same as the old one, the new head has the single inlet VVT fitting, so the #1 bearing cap has the VVT solenoid/valve fitting. Without the VVT valve in place, there is no lubrication to the bearing cap, so a plug with a relief turned in it has to be fitted to channel oil in place of the valve oil channels. Instead of buying a $50 kit, I will just machine one from some 25mm aluminium rod:

The valve spring tool I purchased worked nicely on this head:

Although the 3-digit tappet number is etched on the inside, I confirmed the thickness with a micrometer, in case of any wear:

To avoid scratching the metal cone the valve seal is attached to and to also grip it for removal, a rubber glove between the long nosed pliers and seal cone, works well. All the seals I removed had a pink seal on them (perhaps due to supplier or different requirements for the head being mainly used on a Ford Ranger 2.3). I was expecting green inlet and grey exhaust seals, so will buy a new set to ensure they are correct:

All the parts removed, sorted and labelled as necessary for reassembly:

Edited December 31, 2023 by aerobod - near CYYC

[aerobod - near CYYC]

I ran in to a bit of an issue today, luckily I caught it now, it will be disastrous if I don't sort the issue before engine start. Due to the fact I have a S-VVT (inlet-only variable valve timing) 2.3 replacement head, I thought I just needed to put a blanking plug in place of the VVT solenoid, which would still feed the front inlet cam bearing which uses the same oil feed. That would be the case if I also had a VVT timing cover and block. Unfortunately the 2.0 non-VVT in my R400 has a different timing cover and block.

Here is a photo of a 2.3 S-VVT cover, showing the oil feed that extends from a boss in the block on the oil feed to the end of the head:

My cover has neither of these features, neither does the block have the oil feed boss with a hole in it to match, but the oil feed channel is in the same place in the block casting:

I spent a few hours this afternoon checking for different parts online, measuring the head in various places, tracing all the oil galleries, etc. I think I have a solution, but anyone should feel free to chime in with suggestions, too.

The solution I'm thinking of would entail drilling a hole through the main front horizontal oil gallery and continuing on until the hole goes through into the vertical VVT oil feed gallery behind it. I would then plug both the VVT oil feed where it would otherwise mate with the timing cover and the outside of the main oil gallery. The VVT oil feed hole would need an M10 bolt in it, the new hole would be either M5 or M6, most likely filled with a grub screw held in place with red Loctite.

Here is the entrance to the oil gallery, I will insert suitable material to shield the existing feeds while drilling and tapping the new hole, to avoid debris staying in the galleries.

Edited January 4 by aerobod - near CYYC

[aerobod - near CYYC]

I did manage to prep the head for porting and overall smoothing of the inlet tract into the combustion chamber. All oil and coolant channels have been taped over to keep debris out:

The inlet ports will just need a small amount removed in the lower corners to match the 48mm Jenvey throttle bodies:

The exhaust ports are currently only 37mm diameter, they will be opened up to 42mm diameter to match the exhaust header pipes:

Edited January 4 by aerobod - near CYYC

[rgrigsby]

Incredible attention to detail, it's really interesting to read and see how you are getting on. Feels like you could turn this into a guide and publish it once done!