Supercharging Through Bike Carbs

[Guest ianjenn]

but to get the best from the vvt it needs controling ,dinger prob has the best set up . the controle is even on tickover .

 

dad

 

so how does that work then? You either open the switch or close it what can you vary via the ECU within the VVT? It isn't variable via current only oil pressure?

[Longboarder]

It isn't off/on, neither is it controlled by oil pressure. It is continuously variable, controlled using a PWM output referencing a map of load against revs by the ECU and collating sender input of cam position and crank position to determine degree of advance. Here is one ST170 users DTA S60 map of cam timing/advance for his install.

When you think about it, using a simple on off switch clunks the cam 30 degrees or 60 crank degrees. Now how likely is that to be right? It seems to me that as I currently run with this system on the omex 600 then my cam timing is probably wrong at all engine revs and load but maybe only 20 crank degrees over advanced at high revs.

 

Nigel

 

I could be the only soldier in the squad in step. Maybe I've got it all wrong.

[Guest ianjenn]

I haven't tested the actuator personally but have researched this topic in detail and whilst your view may be valid the overall weight of opinion from my research is that the st170 is a very basic actuator of the on/off variety. Electronically controlled vvt is used by ford but not in this engine. If your st170 is stripped at present perhaps you could test your actuator on the bench and find out for sure?

[Longboarder]

Yes, my spare engine is in bits. However I wouldn't have a clue how to test it. The solenoid powered control valve that sits in the oil supply to the advance and retard chambers in the inlet cam wheel clicks on/off when powered by hand much like an idle bypass valve does. I understood that those were pwm controlled in Fords(IBPV). The power to move the cam timing is obviously oil pressure but as I understand it the pressure being proportionally varied between the advance/retard chambers in the cam wheel is ecu controlled, 0 advance being 0% duty cycle and 30 cam degrees being 100% duty cycle. (Well it certainly could work that way even if it doesn't!)

I have searched internet references and come up with a variety of how it works scenarios. Ford are a bit reluctant to give ECU details apart from describing how the cam chambers are laid out and the structure/plumbing of the valve and its oilway are easily visible.

 

Currently I'm looking at locking the variable cam wheel (cheaply) and having a look at setting the existing cam at about 20 degrees of advance to see what effect that has and experimenting on the rolling road with swinging the cam from there. So the VVT may not be relevant to me whatever way it works!

 

Nigel

[Guest Robin Allison]

Last weekend i was talking to a lad from the West of Scotland RSOC group. He has an ST170 engine in his Fiesta, although it looks like a black top it is an ST that has had the VVT removed. He said it involved a lot of machine work as the cams have also been changed for standad zetec cams. I dont have the full details apart from the £1000 price tag for doing the work.

But it is a very fast car. I'll try to find his build post and link it up.

[Guest ianjenn]

apart from the £1000 price tag for doing the work.

 

I supercharged for around the £300 mark

[Guest old_timbo]

How did you machine the grooves in your pulley? Do you have a tool that has the correct profile? If so where did you get it. I'm just at the planning stage in putting an M62 on my Pinto and sorting out a suitable crank and water pump pulley is probably going to be the most difficult issue. I have a Myford ML7 lathe so fancy a go at modifying a standard pulley. How did you lock the new outer to the original pulley?

I've looked at pulleys that are available from belt drive distributors, but they don't stock automotive PK spec. poly-v pulleys. The other option is to see what I can find down the breakers.

 

Tim

[Guest ianjenn]

How did you machine the grooves in your pulley? Do you have a tool that has the correct profile? If so where did you get it. I'm just at the planning stage in putting an M62 on my Pinto and sorting out a suitable crank and water pump pulley is probably going to be the most difficult issue. I have a Myford ML7 lathe so fancy a go at modifying a standard pulley. How did you lock the new outer to the original pulley?

I've looked at pulleys that are available from belt drive distributors, but they don't stock automotive PK spec. poly-v pulleys. The other option is to see what I can find down the breakers.

 

Tim

 

Good man a fellow charger!! I ground a profile into an old parting off tool (see additional picture in the charger album)Took about 10mins. I then used the dimensions in this link to machine the new ribs at the correct depth and spacing.belt dimensions micro v belt k section. The new outer ring is 4-5thou smaller than the machined crank (using the 1thou per inch for interference fit rule). I then put the outer ring in the oven and the old crank pulley in the freezer. It slipped on nicely...phew!! and I then drilled on the joint at 180degrees, tapped and put in some grub screws for good measure. One tip the original crank pulley is cast and you will need a tipped tool to remove the ribs.

[Guest old_timbo]

Thanks, thats really useful. I think I'll have a bash at using the later Pinto double V crankshaft pulley (I've got a spare) and machine-off the outer V (I've got tipped tools) so have a hub to shrink the new ribbed drive onto. That way I can keep the inner V to drive the water pump and alternator. Did you use steel or aluminum for the drive? Of-course this could be a case where my ambition exceeds my machining ability.......

 

I've been doing a lot of calculations as in the Corky Bell Supercharger book, and a decent intercooler really is the sercret. For 180 bhp at the crank with no intercooler I would have to run the charger at up to 11,700 rpm, generate 16 psi boost, and a lot of heat. With standard guts a Pinto wouldn't last 5 mins. However with a conservative 50% efficient intercooler I can run at up to 9570 rpm and 10 psi and get the same power. Shouldn't be a problem for a standard Pinto judging by the boosts that the Scandinavian turbo nuts run at. Having fully mapable fuel injection (Megasquirt) with wideband Lambda sensor will give me good control of fuel and ignition timing. Seems to be plenty of room in the 2B nose for an intercooler too.

 

 

 

Tim

[Guest ianjenn]

I just used aluminium. if it wears out, I can always make another outer ring. Using the double pulley sounds like a great idea.

 

I plan on fitting an intercooler over winter, but I have to get a smaller radiator first. Suitable intercoolers in terms of size could be from an MR2 or mazda Bongo.

[Guest ianjenn]

anyone interested in having ago, this one looks like the M62 with electric clutch (auction is nothing to do with me)ebay

[Guest old_timbo]

Just about finished rebuilding my M62. They are almost worthless if the clutch is knackered or missing as you can't change the clutch for a fixed pulley. The clutch is prone to slipping, then the bearing inside the clutch over-heats collapses and wipes out the coil! If allowed to continue too long the bearing spins on the casing and then its game over. Mine will end up with a bolted soild clutch, I managed to recover the casing and got hold of the special bearing from Ebay USA. Hope it lasts!

 

By the way, when the supercharger is switched-off I assume the engine can just suck through it, correct?

[Guest ianjenn]

Just about finished rebuilding my M62. They are almost worthless if the clutch is knackered or missing as you can't change the clutch for a fixed pulley. The clutch is prone to slipping, then the bearing inside the clutch over-heats collapses and wipes out the coil! If allowed to continue too long the bearing spins on the casing and then its game over. Mine will end up with a bolted soild clutch, I managed to recover the casing and got hold of the special bearing from Ebay USA. Hope it lasts!

 

By the way, when the supercharger is switched-off I assume the engine can just suck through it, correct?

 

yes, when the charger is switched off it just moves freely to let air through. The clutch gap is set using some small washer shims same as an aircon pump. You just need to check the gap. As for the bearing, in the pulley, it is a standard Sealed bearing 30BG04s13dst2 ID 30mm OD 47mm length 22mm available from any bearing supplier in UK. The bearings behind the drive pulleys are pig to get to. The drive pulleys are a press fit and the tolerance is extremely tight. Only remove these if you have to.

 

I have seen pictures of the M62 with a welded on smaller pulley and you can bolt up the pulley although then you can't turn off and in a kit car it is nice for general crusing to have switched off.

[Guest old_timbo]

I searched high and low for that bearing. I found 1 in the UK through a bearing broker and they wanted £120 I could have used 2 single row bearings with a spacer which are cheap and easy to get hold of, but found the right one in the US for £24. The coil in my clutch was a molten blob hence the need to bolt it up solid. I thought about putting a pulley direct on the input shaft, but as it is only 1/2" in dia. with no supporting bearing I didn't think it was man enough for the job. I think there are M62's used in the US which don't have a clutch and would be better, but they seem to go for quite a lot.

[Guest ianjenn]

I searched high and low for that bearing. I found 1 in the UK through a bearing broker and they wanted £120 I could have used 2 single row bearings with a spacer which are cheap and easy to get hold of, but found the right one in the US for £24. The coil in my clutch was a molten blob hence the need to bolt it up solid. I thought about putting a pulley direct on the input shaft, but as it is only 1/2" in dia. with no supporting bearing I didn't think it was man enough for the job. I think there are M62's used in the US which don't have a clutch and would be better, but they seem to go for quite a lot.

 

I use a small bearing supplier near where I live and he got one no problem. I don't know if he does mail order but someone to keep for tricky bearings compass bearing Its worth keepin an eye on german ebay as I have seen a few clutches come up on there quite cheap.