Cosworth CSR260 Duratec rebuild/swap in S3

[vstryker]

I posted this on the other forum but thought maybe others were interested. And perhaps for those who have done this, please feel free to come in with tips and experiences as this will be my first duratec.

 

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:

 

[vstryker]

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

[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 & re-pin.

 

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]

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

 

 

 

New crank balanced and journals micro polished:

 

 

[vstryker]

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

 

[vstryker]

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.

 

[Off Road SHO]

Wow! That is nice. My guess is that something failed in the fuel delivery system and flooded the chambers with too much fuel. Washed down the cylinders and thinned out the oil?

 

What do you think you will have in that engine when it's all said and done?

 

Tom

[James A]

You are doing things the right way, nice job!

[vstryker]

I don't even want to think about it hah! Although was it about $18k new?

 

 

Wow! That is nice. My guess is that something failed in the fuel delivery system and flooded the chambers with too much fuel. Washed down the cylinders and thinned out the oil?

 

What do you think you will have in that engine when it's all said and done?

 

Tom

[yellowss7]

Can you tell me where you ordered your parts from? I am getting ready to pull the head on mine to see if I can find the source of my coolant pressurization. Thanks Tom

[vstryker]

I bought all the Cosworth stuff such as the rod, rings, seals, and a few gaskets at burton power. The other smaller items I got either from ebay, Amazon or members on the forum.

[yellowss7]

Thanks, I tried calling Cosworth in Indiana today and was sent to a voice mail and got no return call. Really poor service. One Item I have to order are the valve stem oil seals, do happen to know if the stock ford items would fit? or are the seals specific to the cosworth valves? Thanks again. Tom

[vstryker]

Ever since Cosworth closed its California branch, there has been no support at all from my experience. I bought my valve stem oil seals from burton too and it arrived in a Ford package. They look & fit the same as stock ones.

 

Thanks, I tried calling Cosworth in Indiana today and was sent to a voice mail and got no return call. Really poor service. One Item I have to order are the valve stem oil seals, do happen to know if the stock ford items would fit? or are the seals specific to the cosworth valves? Thanks again. Tom

[yellowss7]

Thanks, I'll get them from Ford then. I picked up an ARP crank bolt and have the Cosworth Head gasket. Hopefully I can source the cam cover gasket and front crank seal locally as well. Good luck with the rebuild. Tom

[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:

 

 

 

[vstryker]

Finished exhaust ports

 

 

Close up of CNC combustion camber

 

 

[vstryker]

Next up was assembling the head. Installed new valve stem oil seals on both intake and exhaust. Reinstalled oversized 31mm exhaust and 36mm intake valves. I heard Cosworth says you don't really need to lap new valves onto their seat. But since this is a rebuild, it was an easy decision to grind and lap the valves onto the seat to ensure a good tight seal. Perhaps that is why there were so much carbon deposits on top of the valves when I first took the head apart, maybe it wasn't sealing as tightly as it should be from the factory.

 

 

A bit of grinding and rolling the lapping tool. Didn't take me long, maybe 5 minutes per valve.

 

 

 

 

Continued with head assembly, this tool makes it so easy. After the valve stem oil seals went in, then it was the valves, valve springs, retainers and their locks. Oh yea, I used graphite moly assembly lube for the head.

 

 

 

 

After a few hours, the head was complete minus the cams. When I took the head apart, I made sure I put the same tappets in the same exact place as I did not change the cams or ground new seats so the lash should be the same. A quick lash check on a few and I called it a day.

[John B]

Nice work!!

You just beat me to that engine, I contacted the guy and he said he just sold it.

 

If you have any more questions re parts etc, contact Steve Knapp at Elite Engines. He builds 2.3L Duratecs in very high spec for Swift 016 Formula Atlantic open wheel race cars. They have done a lot of development work and are getting over 300HP plus in unrestricted race trim, but I think a nice streetable 270HP is doable. Had I purchased the engine it would have gone straight to Steve. He's working on a race engine for me at the moment.

 

Steve Knapp

Elite Engines

w 262 306 1977

c 920 918 4531

http://www.eliteengines.com/

[vstryker]

Ok, time for a little update:

 

 

After completing the head, I started working on the bottom end. Installed pistons with new rings:

 

 

 

New mains and thrust bearings installed into block, along with crankshaft. I did not use the plastigauge to measure the tolerances between the mains and and journals, I just used a micrometer instead since they were both new and each was well within the middle of the specs. Torqued in sequence of 20, 40, then 60 ftlbs with arp studs. Reading up on other builds, I know that a lot of people have trouble with the studs getting in the way of the dry sump windage tray. To solve this, you have to make sure the studs and nuts are flush as in the picture. I did a dry mounting of the dry sump pan and all is good.

 

 

 

 

When it came to installing the pistons and rods to the crank, all was smooth until I came across this:

 

 

 

 

I had ordered 4 sets of Clevite CB1838H and 3 of them were the correct ones, the other was something totally different, even though the box says CB1838H on all of them. It was wider by a few millimetres and had a notch in it, needless to say, I sent them right back and Amazon had the correct ones sent out in 3 days. With the correct big end shells, again arp bolts on the connecting rods, the piston assembly was complete.