Escort Sigma 1600 Race Car

[Roadsport]

Re: Escort Sigma 1600 Race Car

Thats good to know Roger. I've seen some nice improvements earlier with this Truetrac diff so thats why I bought it. And this is what I'll run and try out.
Doubt the Titan locker will fit the US 7.5" rear anyways.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Started rebuilding the bottom end today.
The shells were in good enough condition to be reused. So were the piston rings. After all they've only been trough one race weekend.
The same can't be said about the clutch though. It seems I've managed to distort the plate between the cover and friction plate. Thus the friction plate looked a bit too worn too. I guess its due excessive slipping of the clutch. It heats up and... So I needed to order new ones. It's a three week wait though.
I need to learn how not to slip the clutch at ALL.








Put the pistons in. This time with no coating on the sleeves. The coating on the crowns has held up nicely.
Now was the time to try out the bolt strech method to tightend down the big end bolts. I got the bolts measured prior to assembly. In order to reuse them I need to check that they are the exact lenght they were going in. If theres a 0.0005" strech they should not be used again. Re-measuring with that accurasy may well be pretty darn impossible. I guess with those tolerances even the room temperature plays a role. We'll see.
The bolt strech method it seems to be a good and relatively simple way of torquing down the con rod bolts. Only, I need to do it some other time since I just could not find a 3/8" box wrench strong enough for the strech needed.







Also test fitted the new pulley. It fits nicely but looks huuuge.




Now I need to find me a stronger box wrench to get on with the build.

[Tristan]

Re: Escort Sigma 1600 Race Car

a box wrench?

[Roadsport]

Re: Escort Sigma 1600 Race Car

Is that not the correct term for it? Spanner with a 3/8" "loop" end.
Mine was too tiny and I ended up snapping it.

[Roadsport]

Re: Escort Sigma 1600 Race Car

I had a chat today with the Barracu fellas about bending the rear axle. I've done a liitle bit to get some toe in but was soon dishearted due to the violent nature of the process
Now the plan is to give it another go and try to achieve as much negative camber as possible. I have a clean 2cm's of virgin clean unused rubber in the inside of the rear tires. I hope some negative cabber could get than rubber to use. I'll be sure to take some photosof the process. It's somethin you don't see every day. Burning the axle with a blow torch.

[Tristan]

Re: Escort Sigma 1600 Race Car

I remember the legend that is Dave Walker talking about running beads of weld on these type of axles , around half of the tube , and when the weld cooled , shrinkage changed the camber . And there was reports back from people he suggested it to , whotried it and who it worked for!

[Roadsport]

Re: Escort Sigma 1600 Race Car

Yes it works allright. Welds are more work though if you grind them off. The Group A Volvo 240 race car had 1.5 degrees of negative camber. Not welded nor blow torched though.
Helpfull with the A048 tyres but will put some heavy strain for the splines in the diff and the wheel bearings. I did not have this problem back when the regs only allowed regular street tires.

[Tristan]

Re: Escort Sigma 1600 Race Car

how does the other process work ?

[Roadsport]

Re: Escort Sigma 1600 Race Car

I am not 100% sure yet. But heat is the key here too. Thay attach some tracking gauges to the axle and start heating the axle while monitoring the bending.
I'm not sure where exactly the axle needs to be heated in order to bend it to the desired direction.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Took the scavenge pipes out of the sump to check if the mesh filter would have any of those piston coating flakes stuck to them
. No. They looked good other than the rear one seemed like it had some corrosion on it. Almost like it had been on contact with water for a while. The engine is tilted back a bit and water is heavier than oil so that's where the whe water would be.



The front filter looks allright


As the rear one seems to be more corroted.


And so is the pipe work


Again the fron pipe looks fine


Its certainly was not loosing any coolant so I guess It could have just condenced in the engine during the long quiet era
Anyway they are good to go back in once I replace the O- rings.


Also decided to take the extra bits out of the OE oil pump. After all its only function now is to house the front crank seal. Then I istalled the oil pump and rear seal.






No luck finding a heavy duty 3/8" spanner yet. May need a build one from a socket...

[Tristan]

Re: Escort Sigma 1600 Race Car

what do you need the spanner for ?

[Roadsport]

Re: Escort Sigma 1600 Race Car

Hence I decided to use the bolt strect method to torque down the big end bolts theres no other tool for it.
Both ends of the bolt need to be open to allow the gauge to be mounted. Only these bolts are 5/16" and the head 3/8" and they don't make big spanners for tiny bolts.
But I believe cutting a socket and welding it to a rod of some sort would do the trick

[jimmy8v]

Re: Escort Sigma 1600 Race Car

I apologise, I'm a bit of a forum lurker. Thought this might be helpful though. I use an extra long snap on box wrench, have two for different size ARP's. 0 degrees too, so the turning moment is perpendicular around the thread. Unfortunately as always with snap on, not exactly cheap. Other tool manufacturers might make something similar.

http://buy1.snapon.com/catalog/item.asp?P65=&tool=hand&item_ID=68004&group_ID=17469&store=&dir=catalog

[RWD fords rule]

Re: Escort Sigma 1600 Race Car

As I understand it the best way to torque the bolts it to torque them in a vice with soft jaws holding the conrod, place the torque gausge on the, zero the dial, take the gauge off the rod bolt, then get your torque wrench and set it to a low level, now torque the bolt, check how much the bolt has stretched and keep adjusting your torque wrench until you get it up to the correct setting to get the right torque for each bolt, which should be very similar if not the same for each bolt.

Then fit that piston and rod into the engine, nip up the bolts and bring them up to the required torque figure on your torque wrench in one movement instead of progressively torquing them to say 20, 25, 30 etc, ARP say one movement is best aqnd always use ARP lube

Torquing the bolts that way you will know if any bolts are soft, they would get to the required stretch figure with less torque than the rest of them, if that happens bin it.

Another point is that if you get to a torque figure you are happy with and the bolt stretch is a little bit shy of the recommended figure then that is fine also, just make sure you do not over stretch the bolts.

Check the bolt length again after you loosen them at the bench before they go into the engine, if the bolt is .0005" or more longer than it was before you torqueed them in the vice then they have stretched and should be replaced.

Lastly it is best to measure the bolt length with the conrod small end facing straight upwards, holding the rod up in the air with one hand and letting the bolt stretch gauge hang on the bolt with the dial at the bottom, that way you are taking all of the weight off the dial plunger so it will read 100% accurate every time

[RWD fords rule]

Re: Escort Sigma 1600 Race Car

Like this,