Cosworth CSR260 Duratec rebuild/swap into S3

[vstryker]

I finally have some time to start on my long awaited Cosworth 2.3L Duratec rebuild. I bought an engine that came from a CSR260 which had spun a rod bearing on #2 cylinder. It looks like low oil was the cause. For reference, it's a base CSR260 engine, consisting of:

Cosworth 12.0 CR forged pistons
Cosworth rings
Cosworth/Carillo rods
Cosworth HD oil pump
Cosworth/Titan internal 2 stage dry sump
Modine oil cooler, High flow fuel injectors and rail
Cosworth CNC head (not the race extruded full CNC head)
Cosworth 2nd stage cams, race valve springs
Cosworth light weight flywheel
Cosworth/Caterham 2 piece roller barrels

Some pics to start



I started disassembly right away to see what else was damaged and needs replacing



Here is the big end of #2, you can see it scored the journals on the crankshaft:


The other rod bearings were about to fail as well


Took the head apart:


Quite a bit of carbon deposit for 9000 miles, although probably 50% of it were hard track miles:


Pistons were a bit dirty with some debris on it, but not bad overall:

[vstryker]

After close inspection, I'm replacing:

Cosworth rod
Cosworth rings
New 2.3 ranger crankshaft
All new main and rod bearings
ARP main, rod, head studs
New friction washers and bolts
All gaskets and seals

I'm also sending off everything to be cleaned including head, block, dry sump pan. The other 3 rods and pistons will be fluxed and checked for cracks. The same machine shop is also honing the cylinder walls. Once I receive the crankshaft, I'll have the whole rotating assembly balanced.

As far as swap parts go I need:

Engine mounts/brackets
Duratec headers (will reuse my existing Titanium ammo can)
Dry sump tank
Modify the hard oil lines on existing dry sump pan
Duratec bell housing with slave/release bearing
New clutch/pressure plate
New water rail
Caterham engine harness
MBE 9A4 ECU
Uprated fuel pump
Oil catch can
Throttle cable... and probably lots of other little things I can't think of right now

[tipridr]

I still have that water rail if you need one

Hayden

[TurboWood]

Very cool to see one of these apart. Good luck with your build.

If you have any need/desire for the Caterham dry sump bell housing setup let me know. I have all the parts that come with the CSR chassis kit (no oil pan). I also have a full CSR exhaust system (head to muffler, w/cat). I was intending on using some of it for my build, but let me know what you might be able to use.

Daniel

[vstryker]

Some parts have arrived:

Cosworth rod & piston rings
Clevite H rod & main bearings
ARP fasteners all around
New 2.3 Ranger crankshaft
Intake, exhaust seals along with other gaskets, seals
Cam bolts, crank pulley bolt & friction washers







I sent off the new crank, flywheel, clutch cover, and pulley to have it balanced. Also, the rods, pistons, rings, wrist pins will be balanced as well. The pistons and rods set were about 1-2 grams off from another which is within cosworth tolerances but Im expecting them to be within less than a gram once done.

I'll pick up the cleaned block & head this weekend. Then the bell housing & dry sump tank should be arriving next week. Still trying to see if there's an easy button for the engine loom, I don't think I have the time and patience to rewire & repin.

I thought about having my 6speed rebuilt since it will be out with the engine. 2nd & 3rd can be stiff and I sometimes grind 3rd when shifting too fast. Anyone local can do it? if not, I'll do it myself but where to get the syncros & stuff for the caterham 6speed?

[vstryker]

Very interested, I sent you a pm. Hopefully you have the elusive black swirl tower that goes on top of the csr bell housing

Very cool to see one of these apart. Good luck with your build.

If you have any need/desire for the Caterham dry sump bell housing setup let me know. I have all the parts that come with the CSR chassis kit (no oil pan). I also have a full CSR exhaust system (head to muffler, w/cat). I was intending on using some of it for my build, but let me know what you might be able to use.

Daniel

[Doug Liedblad]

Van

You do know about what moose calls the 'jesus' bolt that holds the cam gear onto the crank?

Tighten to some high value, and 1/4 turn more if I recall.

The bolt is a one time use.

Doug

[vstryker]

Yes, I got that crank bolt/washer. I spoke with Kevin, "Papak" on the boards & he said they it was fairly easy to tighten it up. He mentioned he used the timing bolt to secure the crank at TDC, tightened to 75ftlbs & another 90 degrees... All pushing against the timing bolt. Hopefully it's as easy as it sounds because I've read that it sometimes require 2 ppl with a special 3 ft extension tool.

Van

You do know about what moose calls the 'jesus' bolt that holds the cam gear onto the crank?

Tighten to some high value, and 1/4 turn more if I recall.

The bolt is a one time use.

Doug

[Doug Liedblad]

I would not use the timing bolt method.

I have done this a couple of times, always with two people. One holding the crank by the flywheel, the other on the wrench.

It is not difficult doing it this way.

I will come down and help if you need it.

Doug

[slomove]

I am with Doug here. I read posts from several people who bent the timing pin even when tightening the cam bolts not the crank bolt (which has much higher torque). If you bend it really good you may have to cut it off from the inside to get out again. That is for a Zetec but I guess the same applies to a Duratec. For my engine I blocked the flywheel with a clamp while tightening that bolt.

[vstryker]

I might take you up on your offer Doug, thanks. You guys are right, I had doubts about the timing bolt being strong enough & ill block the flywheel as well.

I would not use the timing bolt method.

I have done this a couple of times, always with two people. One holding the crank by the flywheel, the other on the wrench.

It is not difficult doing it this way.

I will come down and help if you need it.

Doug

[vstryker]

Got the block, head and rotating assembly back today. Everything was cleaned and cylinders freshly honed





New crank balanced and journals micro polished:


The pistons, rings, wrist pins were all balanced to within +-0.25 grams!!! That's right, a 1/4 of a gram. I weighed them all and according to my scale they were exactly the same


Same story with the rods, both the big end and wrist pin end were balanced separately to keep it perfectly balanced, and all weigh exactly the same:


Check out the flywheel after being balanced, I thought it was around 9 pounds but the scale says otherwise


I fitted the new rings onto the recently cleaned pistons with reference to the orientation of each ring as set by the Cosworth manual


They did an amazing job of cleaning the old valves. I was surprised they got it this clean as it looked brand new



Here is how they looked before, more on why I think it was so full of carbon deposits later.

[vstryker]

Hayden, I was gone take it off your hands but after seeing how Magnus had to cut a few tabs off of the head, I hesitated and decided to go the CSR route instead.

I still have that water rail if you need one

Hayden

[tipridr]

Yes- its a bit of a challenge to fit that part- definitely not plug and play

[vstryker]

Taking a close look at the intake and exhaust ports on the head, I noticed that the casting isn't as clean as it should be. I know the only machine work Cosworth did was CNC the combustion cambers and maybe a slight port. After all, this is not the full on CNC extruded race head that they offer, where everything is CNC ported. So I took the dremel out and started to work. I was extremely careful not to enlarge or change the shape on any of the ports as this will affect the flow. I basically ground down and smoothed out the casting by polishing it slightly, I would say maybe equivalent of a mild stage 1 port and polish. I tried my best to make sure whatever I did on one port, that it was even all the way across. Even if it didn't make a difference in the flow, it sure as hell looked much nicer after a few hours of elbow grease.

Before and after:






Finished exhaust ports


Close up of CNC combustion camber