Escort Sigma 1600 Race Car

[Roadsport]

Re: Escort Sigma 1600 Race Car

Also offered the new trumpets to the TB's . Their shorter than the ones I allready have, not with full rounded lip and they open wider. Wheter they're any good remains to be seen. Thay are alot lighter than the ones I had earlier.
These are basic jenvey stuff seen on many suped up Fiestas

[Roadsport]

Re: Escort Sigma 1600 Race Car

Cams in and crank bolt tightened down. Replaced four cap bolts with the bolt/ stud bolts from the older Zetecs. The cam cover woll be bolted to these studs. Undoing four nuts instead of 17(counting the coil nuts) really makes removing the cover easier. Don't even need to undo the coill bolts the coils come up with the cover.
The black gunk in the head is one filled up bolt hole I needed to seal due to the older style cam cover.



I hate doing those cap bolts.Its one thing in a STD engine but the stiff springs and hooge lobes makes it feel like the cap you are tightening could give at any minute. Makes tightening them really slow and nerve wrecking. And theres 20 of them.



Also thought of using tougher bolts and a hefty washer for more clamping force to the cam pulleys. I do have locking pins but a little extra safety would not hurt.
Only I'm not sure how tight to torque them. Their 10mm 10.9 bolts. I found a universal chart of recommended torques to different bolts that stated they should be torqued to 74Nm. Does that sound right? The OE bolts are 8.8 and torqued to 60Nm.



oh yeah and the tensioner now has new bearings.

[DH2]

Re: Escort Sigma 1600 Race Car

Nice work - look forward to the next instalment...

Dave

[Graham]

Re: Escort Sigma 1600 Race Car

74nm sounds rather a lot, i think i'd put that setting in a torque wrench but do them up by feel, either stopping when it felt right or the wrench clicked off

[Roadsport]

Re: Escort Sigma 1600 Race Car

74nm sounds rather a lot, i think i'd put that setting in a torque wrench but do them up by feel, either stopping when it felt right or the wrench clicked off

I decided not to change bolt material in such a critical place. After all had no issues with the OE bolts. I believe wiser men than me have decided the torque spec and material.
And after all I have locking pins to stop any pulley slipping in the cam.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Busy busy busy...

Drilled a new hole (actually two, the first one was no good) in the inlet cam pulley for better locking pin location. The pin was originally located wrong taking all of the pulleys movement to one side when timing the cam. Meaning I could only advance the cam on the rollers.
Also dialled in the cams. Then I measured and marked the limits for retarding and advancing the cams. This will make adjusting the timing on rollers a lot easier,safer and faster.

Starting to look good for the weekend. Only needs the clutch, throttlebodies, a bit shorter aux belt and a oil pump belt and its all ready to slip back in the engine bay. The exhaust manifold will be next on the to do list.
Also calculated that I've shed 3kg of rotating weight in the powertrain and 4,2kg over all. Not bad.

Dialing


Tried on all the covers and pulleys to see if they'd actually sit right...well after a little tweeking and fitting they all found their place.

[Tristan]

Re: Escort Sigma 1600 Race Car

Also dialled in the cams. Then I measured and marked the limits for retarding and advancing the cams. This will make adjusting the timing on rollers a lot easier,safer and faster.

Also calculated that I've shed 3kg of rotating weight in the powertrain and 4,2kg over all. Not bad.

Thats a fair bit of rotating weight!
ood thinking on the limits of the cams . What clearance have you at the closest point?

[ShawSpeed]

Re: Escort Sigma 1600 Race Car

Looking good Markus.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Thats a fair bit of rotating weight!
ood thinking on the limits of the cams . What clearance have you at the closest point?

According to my calculations and measurements I should have 2mm clearance at the closest point. I do not dare to drop the clearance no closer than 1,5mm. On the exhaust side that is bit on the tight side. So a whopping 0,5mm of room to open the valves at the TDC.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Looking good Markus.

Thank you Jon.

[Roadsport]

Re: Escort Sigma 1600 Race Car

Few meaningles poses before installation.
Needs only the clutch now. I like them new trumpets.

[Tristan]

Re: Escort Sigma 1600 Race Car

According to my calculations and measurements I should have 2mm clearance at the closest point. I do not dare to drop the clearance no closer than 1,5mm. On the exhaust side that is bit on the tight side. So a whopping 0,5mm of room to open the valves at the TDC.

eeek , thats more than I have! I really need to pocket my pistons.

[Roadsport]

Re: Escort Sigma 1600 Race Car

How much do you have? On the exhaust side in particular

[Tristan]

Re: Escort Sigma 1600 Race Car

only about 1mm . Standard flat top pistons .

[Roadsport]

Re: Escort Sigma 1600 Race Car

Have you allready read trough this one

http://www.turbosport.co.uk/showthread.php?164063-How-to-cut-valve-reliefs-in-a-pinto-engine-with-basic-tools

0,5mm of more clearance would not hurt. I believe the risk lays in engine brakes and gear changes with high revs and hot engine where you may get some stretch or play in the belt between them pulleys. This will retard the exhaust cam and may cause the the valves to hit. But at the end of the day who will ever know if such a thing will ever happen or would the belt give even if it would. And you're limiter was at 7500? So you may be off the hook.