Tear Down and Rebuild of My R400 Duratec Engine

[7 wonders of the world]

I would say yours is easily equal if not better than a R500D James, Taking into account the approximate run down calc and assuming the altitude correction,

I have yet to see a dyno print of a R500D giving the claimed 263 in 'factory trim',  probably leaving myself open here... lets see if anyone can post one....

[Shortshift]

261 @ 8400rpm, using gloopy 10W-60 oil, so probably hitting 263 on the head with Caterham Cars' recommended (thinner) oil. 

Standard R500 spec and build, but mapped by the brilliant Steve Greenald.

If you're limiting to 8200rpm, James, that will be a relevant factor too.

James

Edited May 4 by Shortshift

[7 wonders of the world]

Thanks James,

I've heard of many getting the numbers after investing in a mapping session, what were you numbers on the first dyno run before Steve got to work rounding up the stray ponies..?

[Shortshift]

I'm not sure, Neil - I haven't got any curves and I can't remember.  What I do know, though, is that the driveability was transformed by Steve's mapping session. 

It's well known that, ex-factory, R500s had appalling torque curves with huge dips and holes around the 5000 and 6000rpm regions, leading to dreadful driveability whether on road or track.  Now, my car just pulls and pulls and is a pleasure to drive.  It also has a rock-steady idle too (well, it does now - again - since Stu Cresswell diagnosed and fixed no fewer than four dreaded failed valve springs, back in autumn last year when his wonderful Premier power was still a thing).

James

Edited May 4 by Shortshift

[aerobod - near CYYC]

On 25/03/2024 at 01:52, Colin_T said:

Sharing of experiences with jenvey return spring setup and the R clip they use:

i had the R clip come off on one of my race cars causing the return mechanism to fly off and of course throttle return became interesting to say the least….
  ever since then on either mine and any customers cars I always swapped the R clip out for a split pin. 
 

Colin 

I had been a bit slack in putting a split pin in place of the 'R' clip as I didn't have the right size in my parts box, until last night when I accidentally popped the 'R' pin out when turning the throttle quadrant by hand to confirm the maximum TPS voltage hadn't change since before the rolling road session.

.......First task this morning was to go to Canadian Tire when they opened and buy a pack of 1.6mm split pins, now no risk of the pin coming out and potentially jamming the throttle with disastrous results.

[7 wonders of the world]

Good reminder on that little R clip, 

whilst your in the area, its also worth replacing the R clip in the clutch pedal clevis pin too 

[aerobod - near CYYC]

The engine performed very well for my first track day of the year, today. Best described as an “angry bee” from a noise and responsiveness perspective.

Only one problem I have to solve is that I need more oil cooling. With the old 210bhp Duratec with plenum, track use would typically see coolant at 80C, 5w50 oil at 5.5bar at higher RPMs and just over 2 bar at idle after coming off the track. Bulk oil temperature in the oil tank would be 80C (likely about 20C below dry sump temp).

With the new engine after several flat-out laps, oil temp would quickly rise to 90C in the oil tank and pressure would drop to about 4bar at higher revs, I briefly saw 100C in the oil tank and an idle pressure of 1.8bar after coming into the paddock. Coolant temp would also be 90C or so at high speed.

I ended up running flat out for the beginning of each session, then keeping it to 6000RPM or so and using 4/5th gears instead of 3/4/5, but my speeds and lap times together with oil and coolant temps were than back to the same as with the old engine.

I had put a 12% lower speed water pump pulley in to avoid cavitation at high revs, but may put the standard pulley back in. I think in addition to that, both a larger oil cooler and 10w60 oil may be needed.

[7 wonders of the world]

Glad it all went well James.. 

For comparison my. Previous engine with Raceline DS and no cooler could see 130 degrees peak temperature measured in the trough in the finger filter I could lower this pretty quickly by using 5th on the Bentley straight instead of 4th and all the revs. 

I run a TTV under drive front pulley and have no coolant temp issues at all. 

I was taking mine to 8500rpm.

 

I have added a 19 row cooler and oilstat now though because of my rad it's mounted behind not in the ideal place but I am not expecting any issues... We will. See on the track 

[aerobod - near CYYC]

Hi Neil,

I think I will go with a 19-row Setrab oil cooler and oil thermostat as the next fix, although mounting the thermostat will require some re-plumbing of the oil lines. For the next track day in 2 weeks, I will take along the old pulley and see what swapping to it does. I want to try and keep the oil pressure at 5.0bar and above at high revs in all temperature conditions.

When is your first track day with the new engine?

[7 wonders of the world]

Hi James,

 

No that was the previous engine  last year, my first track day for this one is in July at Oulton Park..... and I can us 9K this time too..... 😜

[aerobod - near CYYC]

I ordered a Setrab 19-row Series-6 oil cooler with -12 fittings, the Mocal 19-row -12 ones seem to be back ordered in general. It is interesting that most of the Mocal and Setrab coolers are interchangeable with dimensions and rows being the same down to the millimetre, so the feed hoses will fit exactly the same as the current cooler. With it being taller than the 10-row one and the top needing to be higher, I will probably make some mounting blocks that locate on the existing Caterham brackets, to support both the top and bottom flanges.

I have decided that I won't put in a thermostat for now, as that will mean 4 new feed hoses. If it over cools for road use, I will just blank off part or the whole of the cooler.

[aerobod - near CYYC]

I now have a 19-row Setrab oil cooler fitted, but also did a few other cooling relating modifications.

To use the existing oil cooler mounting brackets, I machined 8 spacers (4 threaded, 4 with through holes) that allowed a long bolt to pick up on the threaded spacer at one end and a short bolt at the other end:

The oil cooler could then be mounted in the optimum position:

I then cut some holes in the radiator cowling to allow a top rubber flap to be installed (to complement the existing 3 on each side at the rear of the cowling):

 

The flap was made from a piece of 2mm rubber sheet used for lining tool box drawers, the idea is that it will open at speed to let air escape above the cowling, but will be sucked closed when the car is stationary and idling to maintain the fan efficiency. The mounting strip was partially bent upwards to make the cowling top edge more rigid due to the large amount of material removed from it.

A partial rubber air dam was also fitted:

Then finally an R500-style hole was cut in the nose cone to allow air to escape, using a picture of an R500 nosecone from the Caterham Parts website to scale the dimensions of the hole as accurately as possible:

The finished nosecone in place with some edge trim around the hole, but I will probably get some black mesh to cover the hole to hide the coolant bottle a bit better:

 

[KnifeySpoony]

Wow that's a big cooler. I'm curious to see how your temps respond. Also maybe I missed it, but do you drive it on the street as well? With my little stock cooler on my newer 420R, temps in the tank are scary low on the street, but that's without a Tstat. Will be interesting to see how you get on. 

 

To add some data points to the thread - my oil temps on track usually run about 80C after fully up to temp. Highest I've seen was 88C. Water temp around 95C peak. Oil pressure never drops below about 4.2bar even at its hottest. I'm running the Motul 5/50.

[aerobod - near CYYC]

7 minutes ago, KnifeySpoony said:

Wow that's a big cooler. I'm curious to see how your temps respond. Also maybe I missed it, but do you drive it on the street as well? With my little stock cooler on my newer 420R, temps in the tank are scary low on the street, but that's without a Tstat. Will be interesting to see how you get on. 

 

To add some data points to the thread - my oil temps on track usually run about 80C after fully up to temp. Highest I've seen was 88C. Water temp around 95C peak. Oil pressure never drops below about 4.2bar even at its hottest. I'm running the Motul 5/50.

I do drive the car on the street and have always had slow oil temp increase. I was planning to put in an oil thermostat, but it is a bit more complicated with a dry sump and will require a lot of extra plumbing, as you can’t simply use an oil filter sandwich thermostat. The “Plan B” is just to put a piece of plastic over part or all of the oil cooler, as needed.

My temps on the old R400 engine were similar to yours, but with the extra 50bhp or so, the original cooling isn’t adequate now. I saw dry sump tank oil temperatures as high as 100C, likely 120-130C at the bearings. I saw oil pressure drop to 3 bar at higher RPM with Castrol Syntec 5w50 at the last track day when running flat out, with temps rising and pressure dropping compared with the old engine within a couple of laps as the cooling system seemed to be overwhelmed, returning to normal again after a couple of laps of keeping the revs below 6500RPM.

[KnifeySpoony]

I know many people would say there's nothing wrong with those oil temps with modern good oils. But having some headroom is surely a good idea. You can always block it off for cooler days. Unfortunately with my pusher fan, it's not easy to block my cooler, so i just block the lower air inlet on my race style nosecone, which only helps a little to keep temps up while street driving. Cold morning drives to the track on the freeway have me fearing for my engine. 

[rgrigsby]

Not quite the same engine but with my 2.3l Duratec running around 250bhp (7500rpm rev limit) I typically see oil temps just under 100c after a track session. I'm not running an oil cooler but do have the large Brise kidney shape oil tank in front of the engine.

I've been seeing those sorts of temperatures since the engine was installed in 2005 and never had any issues.

FWIW I'm running Fuchs Titan Race Pro S 5W-40, recommended by Ammo who built the engine.

[AlastairA]

On 20/05/2024 at 03:16, KnifeySpoony said:

To add some data points to the thread - my oil temps on track usually run about 80C after fully up to temp. Highest I've seen was 88C. Water temp around 95C peak. Oil pressure never drops below about 4.2bar even at its hottest. I'm running the Motul 5/50.

Mind if I ask where you're measuring the oil temp - using the sender at the bottom of the tank, or elsewhere?

[aerobod - near CYYC]

8 minutes ago, AlastairA said:

Mind if I ask where you're measuring the oil temp - using the sender at the bottom of the tank, or elsewhere?

Hi Alastair,

I use the sensor in the bottom of the dry sump oil tank, so it is 20 to 30C less than at the scavenge pump due to passing through the oil cooler first. It reflects the temperature of the oil entering the engine as opposed to exiting it.

[AlastairA]

Thanks James - so a temperature of around 80C at that point would be good? I'm planning on wiring up the sender at the bottom of the tank and trying to get a feel for what a sensible oil temp should be for road use, and therefore decide whether to block the airflow over the oil cooler.

[aerobod - near CYYC]

8 minutes ago, AlastairA said:

Thanks James - so a temperature of around 80C at that point would be good? I'm planning on wiring up the sender at the bottom of the tank and trying to get a feel for what a sensible oil temp should be for road use, and therefore decide whether to block the airflow over the oil cooler.

For road use I like to see 70 to 80C in the tank on my engine, which would put the bearing oil temp at around 80 to 110C. For track use I'm trying to get the oil tank temp in the 80 to 90C range, with bearing oil temps likely around 100 to 120C.

[7 wonders of the world]

Mines measured from the trough (peak temp) in the dry sump pan the sender is mounted in the finger filter retainer. 

[aerobod - near CYYC]

1 hour ago, 7 wonders of the world said:

Mines measured from the trough (peak temp) in the dry sump pan the sender is mounted in the finger filter retainer. 

I was thinking about moving the sensor to the finger filter, Neil, but I've decided that the minimum oil temp is given with the oil tank sensor (so I know when I can give the engine the full beans) and I'm more concerned about oil pressure being high enough with the hot oil, which I get with the current oil filter housing pressure sensor. Ideally a second sensor in the finger filter and a 3-way instead of 2-way switch on the temp gauge would be the ideal solution.

[KnifeySpoony]

My sender is in the oil tank, which is after the cooler (coldest point). I have seen various numbers thrown around re: the delta between tank temp and sump temp - does anyone actually have any hard data on this as measured on their car? I know it will depend on the cooler and tank/plumbing setup, as well as ambient temp, speed etc, but I have wondered how much hotter it really is in the bearings, head, and sump while underway.

[7 wonders of the world]

I much prefer to accurately measure my peak temperatures and approximate the tank temp, as opposed to the other way around this way you know what numbers your oil and bearings are actually seeing under the most arduous conditions on track,  a simple dual sensor switch would be the ideal.

 

[7 wonders of the world]

My dash will record max oil pressure oil temp and water temps etc which I can check after each track session,  admittedly the OP is no real use as this will likely as not see its highest value on the out lap

The Caterham 420 race teams are now fitting a softer oil pressure relief spring in order to gain a little more power....