Escort Sigma 1600 Race Car

[Roadsport]

Re: Escort Sigma 1600 Race Car

I was thinking of maybe buying it back to wait quitly in the corner for alloy block throttlebodies and a serious roller cam set up...

[Roadsport]

Re: Escort Sigma 1600 Race Car

bloody hell a snapped pinto crank! what the hell happened to it, did they do a 20 lap race with no oil in it or drop it off the top of the iffel tower!!!!!!!!!!

It experienced a severe outing. They drove off the road and held the ankle straight. Not sure wheter it rolled and overreved or hit sonmething.
We'll see if it only needs a new crank or a bunch of new parts. Would be a great opportunity to upgrade to a cossie crank.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Right so did something on the engine for a long time.
Dismanteled the bottom end to see the state of the shells and see what caused the marks in the cylinder walls.
Well the high end teflon coating is all but gone from the piston skirts. And there are similar marks in the pistons. So I believe it's piston slap that is causing these gazes.
Propapbly due to having the wrist pin in the middle of the piston.

Is there a way to avoid these markings? Or do I just need to live with it.
Obviously the teflon did not do the trick. Would imroving the bore lubrication work?

[Roadsport]

Re: Escort Sigma 1600 Race Car

Right. It's been a while but some baby steps toward the evo II have been taken.

The engine block has been honed and is good for more action. Hopefully I'll avoid the markings this time.
No obvious reason what caused them was not found. But talking to some people convinced me its not due to oil starvation.
Some say they could've been caused in the original start up due to engine beeing cold some say overheating... I say I don't know. It has not overheated that I know of. So we'll see. The machine shop fella said it could even be the teflon coating that chipped away that did it. So no drastic changes are done to the bottom end. Even the bearings are good to go.
Only the ARP3.5 super con bolts are new. Safe up to 9200rpm's and only 5/16". Not bad but costs 260€ per set of eight
Cheaper than new rods with 5/8" bolts though.


Here are the pistons after only two dyno sessions and one race weekend. You can chip the coating with a nail.




Another new thing is a lighter flywheel. The old one was 4,5kg's and this one is 3,3kg's so so hopefully I'll see more revs at the end of the main straights. Also I'll need to order a new prop shaft. I needed to use a 40mm thick mild steel spacer and it is rather heavy.
Replacing that with the correct lenght prop I reckon I'll save a good 0,5-1 kg there. So propably 2 kgs off the power train weight.







I'm still waiting the head back. Meanwhile I guess I could do a mock up build using empty block and a spare head to start building an alternative exhaust manifold.

And still need to save up for

[Tristan]

Re: Escort Sigma 1600 Race Car

Why the LSD change?

[Graham]

Re: Escort Sigma 1600 Race Car

the piston just looks to me like its just picked up grit from honing

[Roadsport]

Re: Escort Sigma 1600 Race Car

You posted the fifth hudreth post on my thread.

May well be. The slight similar markings in the big end and main bearings suggest the same. Hopefully I've seen the last of this kind of markins.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Why the LSD change?

I've wanted to try the Torsen type LSD for ages now. With my current rear axle the Eaton True Trac LSD is more affordable than Quaife units.
I'm hoping to achieve even better turning in and faster corner speeds. I now have the Ford Trac lok which has the down sides of the truetrack but only some of the benefits.
Plus the torsen is supposed to have less power loss than conventional friction LSD's

[Roadsport]

Re: Escort Sigma 1600 Race Car

Did some tinkering today. I really enjoy doing little things like this while waiting for the bigger parts to arrive. As I am changing the alternators position I need to install an idler pulley in the face of the engine.
This means I need to get rid of the engines original engine mount.

M-sport to rescue.


Offering the bracket to an "customer" engine


Now with the belt cover on


And with the pulley



Seems to work fine, only now I have a huge gap for debree and stones to violate my cam belt
I need to modify the Bracket a bit. Deed to mill the upper bolt hole partially bigger to get the bolt head flush with the bracket. Do you think it can be done or are the walls too thin?



Once the bolt is flush with the bracket its quite straight forward to fill in the gaps.
Just need to replace the cardboard with a carbon sheet left from the airbox project to get the nice look I value so much





Tomorrow I should get my ARP bolts and the bolt strech gauge. As I pick them up I'll drop the bottom end parts for re-ballancing due to new lighter flywheel.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Picked up the ARP 3.5 con rod bolt today. Also got my bolt strech gauge, or a measurement gauge as my daughter called it, today. While I was on a move I dropped of the bottom end parts to be re-ballanced with the new flywheel.




I also went over my head and ordered the True Trac today

[Roadsport]

Re: Escort Sigma 1600 Race Car

Can you tell I'm just a tad exited to try out the new LSD.

[Graham]

Re: Escort Sigma 1600 Race Car

i see! its a torsen or torque biasing diff, like a quaife ATB, i wonder how this one performs which only one wheel firmly on the ground?

[Roadsport]

Re: Escort Sigma 1600 Race Car

It doesen't.

[Tristan]

Re: Escort Sigma 1600 Race Car

so , with less aggresive biting , you're hoping it'll not try to push the nose forward?
What are M-Sport like to deal with? do they have a catalogue of parts , or how did you know they sold them units?

[Roadsport]

Re: Escort Sigma 1600 Race Car

The true trac converts the torque to the wheel with best grip. At a race trac it means it wil apply the force to the outer wheel rather than try and spin the lighter inner wheel.
This alone will help the turn in. And as the LSD is not solid or tight it should not push the nose out.
M-sport supplys Formula Ford parts I bought this of an FF outlet.