As Graham says that is one big pulley on the alternator, Brise and all the other alternator use much smaller pulleys than that, I would argue that this is for a good reason
As Graham says that is one big pulley on the alternator, Brise and all the other alternator use much smaller pulleys than that, I would argue that this is for a good reason
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Yes thats usually the case. The alternator pulley is the smallest one since it needs to spin fast to generate charge.
The alternators revs depend on the ratio between the crankc pulley and alternator pulley. The smaller the cranck pulley the slower the alternator spins. Same Effect ofcourse works counterwise. Usually on a racing engine both (all) pulleys are modified.
Underdrive and dampened crank pulley is not available for the Zetec SE so therefor I need to use the rediculously large pulley. Its the same diameter as the crank pulley so the alternator spins the same speed as the engine In this case 5000-9000rpm while racing. I believe it is enough. I hope its enough. But if not its easy to install smaller pulley.
And Brise had even larger pulleys only not 6 grooved ones.
They had 133mm diameter as mine is 125mm. And think if that alternato pulley is mated with underdrive crank pulley.
Anyway I'm not at all 100% sure will it work I only think it will and sure am gonna try. Not a big deal to improve if I've gone wrong with this one.
And I do agree it looks goofy large.
Bracket number two in the making. The material chosen is 15mm strong Zinced iron.Weights like shit compared to the earlyer one. But I hope this one can take the beating.
Have to find a proper drill to make holes in this one.
Those small holes was on the material when I got it from the scrapheap.
Tiny notch had to be made to fit even with the shapes of the FWD engine mount.
Welded the two pieces together and cleaned up the seams a bit.
High reving engines .. plastic tension arm ... plastic arm flexes under fast rev increases and lets the belt slip momentarily, also damps the vibration...
Gartrac sell them
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The bracket looks stronger, but the bolt will be the weak point now. The alternator will try to oscillate under load, particularly when you go over a kerb. The flywheel effect of that pulley isn't going to help much either. You'll probably still sheer bolts off.
Ideally, at least one of the alternator lugs needs to be supported on both sides. Both my brackets (untested) now pinch the lugs, which should prevent oscillation/vibration, and ultimately, the bolts from shearing.
Bottom bracket
Top bracket
Your new one certainly looks better, more substantial than before, but I guess you need to try it now, and see if the fix has worked, before making further modifications.
I think I'll try it with this one unless I get another lecture again from co racers
I'll have to check into those plastic tension arms and perhaps invest to a hd 12,9 grade bolts.
The huge pulley however will reduce vibrations since the alternator spins a halluva lot slower than with original pulley.
Would a thick washer under the bolt end help any ?
Last edited by Roadsport; 21-08-2009 at 10:40.
I think I'll invest in some Nord lock washers.
They really are the best way to prevent the bolt from coming loose under heavy vibration. And bolts seldom brake if they're snug and tight. But if they get to resonate they'll more likely break.
Finally got some good news from the machine shop. The head should be finished soon.
I sent the vernier pulleys to the shop today to have them fitted to the cams and to have the cams drilled for the locking pins.
Finally I feel like the project is moving along.
Coor. What coating is that? Nickel plated? Chrome plated?
Decided to leave the cabin heater out from the water circulation. Thats why I nedded to plug the thormostat housing. The new RWD water outlet in the cylinder head does not have a outlet for the heater.
Removing the heater from the cabin should take some weight off the front end. And It is simple job to do the plumbing now.
Hey Marcus....it's looking good.
On our plumbing we also got rid of the heater. We used the small outlet on the black plastic thermostat hosuing as the inlet connected to the top of the header tank....it allows for expansion then......could you not have done this rather than blanking it? or do you not have a seperate expansion/header tank.
On the back of the head we connected the small 8mm bleed up to the header tank also so no air gets trapped in the head. The swirl pot also has a bleed in the top which goes to the expansion/header tank.....as does the bleed in teh top of the radiator which in our car is at the front (engine is mid mounted).
we have no overheating, expansion or trapped air problems. Although the Samco bill was crippling!
I was planning to keep it as simple as possible.
I was planning on putting in the Focus coolant tank / header tank (not sure is that the right word?) on my Sierra radiator to keep the pressure high enough and thus prevent overheating.
On the older Zetec S's the header tank is connected directly to the radiator. As I now have. But on the modern Sigmas the header tank is connected to the heater inlet in the thermostat housing via T - piece. I'm going with the older, more simpler way. It may still need to change the radiator tough. And I'd like a shorter one to leave room for the cold air intake for the engine.
So I can plug the heater inlet and spare myself from the trouble of putting in another hose. Coolant can expand to the header tank via radiator. I still need to pull the de-air hose. We'll see wheter these plans of mine work.
Jon has a single inlet thermostat housing for sale. But it had no groove for the O ring and I'm not a big fan of glue sealants. And its quite a task to order stuff from Jon to Finland. So I decided to do one myself from the OE housing.
Some pics to illustrate what I mean.
The pic below is the modern Sigma.
And the plumbing in the pdf file is the my choise. The simple mans choice.
SEE THE PDF FOR THE OLDER PLUMMING
img-904185536-0001.pdf
The cylinder head is finaly ready !!!
Cant wait to pick it up and to start to measure the true compression ratio. The 10 month wait is over.
Last edited by Roadsport; 09-09-2009 at 12:32.
Nice to finally see what this engine is going in Markus.
Dan
Hi Dan !
It's even nicer to see the engine coming together. I'll pick the head up Friday. Its an 8 hour drive there and back but I want to collect it personally.
You cant even imagine how glad I am to FINALLY get the head back.
Now all i need is the wiring, the ecu, the oil tank, oil plumbing, waterplumbing and the exhaust manifold. I think it will be a creation of your truly. Almost there then
Yep! Unfortunately mine is being split as we speak! Need the cash for university. Will come back bigger and better with a duratec in a year or two I think!
Dan
Oh, too bad. But thats the way it goes.
You really should stick with the Zetec SE's arent you kind of obligated to ?
But I guess Duratec is allowed. How much is Shawspeed involved with the Duratecs? You allways hear the talk about sigmas but Duratecs aren't so commonly
linked to Shawspeed are they?
They've done quite a few a few years back when there were kit cars being built.
Dan
good work. keep it up
Hmm - seen what sort of cash I get from this braeking of the fiesta. I wouldn't mind a 1600 Sigma Mk2.
Most of the expensive is in the dry sump really I guess, and management, oh, and bodies.
Christ. This could all start over again.
Dan
Started working on the engine mounting issues today . Got a tip from Moggy to extend the oil pump connect plate to attach the engine mount to it.
And thats what I plan to do. Quite tight squeese tough.
Made a model from card board and the plan is to have the plate lazer cut from high grade aluminium. And for the bling factor maybe have it anodized.
Drew the outlines of the engine mount flange with a marker.
Very nice!
did you change the valve sizes? we run standard inlet and larger exhaust.
Some pics of the test build. Measuring the clearence between piston and valve with very scientific blue tack method
Job had to be left unfinished. I had to attend to a house warming party.
But I did some masurements and it seems the clearance is onugh for now. Still have to measure the compression. Ill have to skim the head and check the clearance again.
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