Another OHV M90 build

[Dono]

Here's a bit of a write up on the M90 generations.
http://rivperformance.editboard.com/t7823-faq-m90-supercharger-info

89-93 M90's had no coating on the rotors.

 

[jd4242]

Here's a bit of a write up on the M90 generations.
http://rivperformance.editboard.com/t7823-faq-m90-supercharger-info

89-93 M90's had no coating on the rotors.

Aww interesting. I knew the gm m90 was more efficient and made more power but never really knew why.i knew the inlet was larger and could be made larger more easy but didnt know about the coating.i knew the 3800 had two or three different coating and know the gen 5 is the best but some say the gen 3 was more reliable because i think they have changed or went back to that coating lately. So really your be fine just wont be as efficient or boost as much as low.

 

[Dono]

Well, a Friends uncle has a press. Im in luck. I still don't have my rebuild kit though.
It shipped Monday of last week.

I tapped the shaft out, snout bearing and seal, and case needle bearings with sockets, extensions, and a hammer. They came out pretty easy, I was surprised.

Now, I can tke the case and snout in for an estimate on powdercoating.
Also, I can take the shaft around to try to find a piece of pipe that will work for removing the shaft bearing. That will need a press for sure.

I'll be using the press for sure when inserting the new bearings. I have to say, Im really amazed how easily the shaft, snout bearing, and needle bearings came out.

Im thinking gun metal grey also on the color. Hate to be a copycat, but the ford grey paint just looked not nice.

 

[Dono]

I mounted my boost/vac gauge. Pretty easy, really. I'll see how it works out.
Still no bearings for the M90. Stuck in customs.
I found a guy that will powdercoat the casing, but I have to wait till he has another job he can piggy back it with. Good guy, and the price is right. If I want it returned fast, it would cost a couple hundred bucks. I can wait.

 

[rocket 5979]

I mounted my boost/vac gauge. Pretty easy, really. I'll see how it works out.
Still no bearings for the M90. Stuck in customs.
I found a guy that will powdercoat the casing, but I have to wait till he has another job he can piggy back it with. Good guy, and the price is right. If I want it returned fast, it would cost a couple hundred bucks. I can wait.

Depending on if he is stripping the old grey epoxy coating off it should only cost in the $50 range for powdercoat and $25-$40 for the stripping. That is USD so maybe the USD to CAN conversion is getting me here. But a few hundred for coating such a small item is high, even for expedited service.

 

[Dono]

I agree. Ive gone all over the city.


it seems no one wants to bother with a small item.

 

[rocket 5979]

I agree. Ive gone all over the city.


it seems no one wants to bother with a small item.

That's crazy. I usually go to the local powder coating guys who have small operations because they are more hungry for business and do a good job because they want you to keep coming back. For that much I would think about just buying my own PC equipment and doing it myself. Of course the garage might not like having even less room.

 

[jd4242]

That's crazy. I usually go to the local powder coating guys who have small operations because they are more hungry for business and do a good job because they want you to keep coming back. For that much I would think about just buying my own PC equipment and doing it myself. Of course the garage might not like having even less room.

If i had room for an oven i wouod buy my own stuff too.would love to be able to coat many parts!

 

[jd4242]

I agree. Ive gone all over the city.


it seems no one wants to bother with a small item.

Thats the same around here,noone will touch anything under a $100. They are pretty busy around here,think it was like $150-200 just for my valve covers,why i opted for paint!!its was in the $200+ for them to do my charger.i would ship my stuff to turtle before i would ever pay that much!!

 

[jd4242]

I mounted my boost/vac gauge. Pretty easy, really. I'll see how it works out.
Still no bearings for the M90. Stuck in customs.
I found a guy that will powdercoat the casing, but I have to wait till he has another job he can piggy back it with. Good guy, and the price is right. If I want it returned fast, it would cost a couple hundred bucks. I can wait.

What gauge is that?

 

[Dono]

What gauge is that?

http://www.glowshiftdirect.com/elite-10-color-30psi-electronic-boost-vacuum-gauge.aspx

I thought about trying to powder coat myself also. But, surface prep (Sandblasting?), oven (Family wouldn't be happy with me setting stuff in our oven at home), and powder coat equipment. Then supplies.

 

[jd4242]

your hooking it up after blower right?witch leads me to the next question or point,how are you hooking up you fuel pressure regulator?i think it needs to be after the sc also.from what i understand when there is vac it lessens the pressure and when there is no vac it increases fuel pressure.so only place that happens is after the blower right?before the blower it should be creating vac ALL the time now

 

[rocket 5979]

your hooking it up after blower right?witch leads me to the next question or point,how are you hooking up you fuel pressure regulator?i think it needs to be after the sc also.from what i understand when there is vac it lessens the pressure and when there is no vac it increases fuel pressure.so only place that happens is after the blower right?before the blower it should be creating vac ALL the time now

On a roots type of supercharger setup when you place vac lines pre-blower and TB you will see neither vacuum or boost. Post TB and pre-blower you will only get vacuum but no boost. Post TB and blower and you will get vacuum and boost.

You have a few choices when it comes to hooking up an aftermarket fuel pressure regulator (FPR). You can either boost reference or not boost reference it. Doing the boost reference is all about keeping the same injector delta (pressure drop across the fuel injectors) at all times during idle and accel. The reason for this is because how the pressure or vacuum acts on the fuel trying to come out of the orifices in the fuel injectors. When in boost the extra pressure pushes back against fuel pressure in the fuel system and less fuel will come out. When sitting at idle with 20in/hg vacuum (roughly -10psi vacuum) then the vacuum in the intake manifold will tend to suck fuel from the injectors.

In a non-boost referenced FPR in a supercharged vehicle your overall fuel pressure read by a FP gauge will remain at a constant psi. But the actual psi making it out of the injectors in relation to the pressure/vacuum in the intake manifold will vary. So if I set my FP to 43 psi without the car running then when I crank it and it sits at idle my gauge is reading 43 while I am actually injecting in about 53 psi worth of fuel because of the -10psi vacuum in the intake. When I get into boost this situation reverses and I will get proportionally less fuel into the intake manifold because of the boost pressure pushing against the fuel in the rails.

A boost ref FPR will ensure that whether you are in boost or vac that your pressure drop measure across the injectors (aka inside the rail before the injectors and post injector inside the intake manifold) stays the same. Your read FP on the gauge will increase or decrease of course since FP in the system is raised or lowered to compensate in a 1:1 ratio for the boost or vac the FPR sees.

As long as you know your overall FP will not exceed any internal pressure bypasses that your fuel pump might have then I recommend to boost reference your FPR if it has the capability. That way it will prevent you from running out of fuel on the top end or just putting your fuel injectors under a duty cycle that may be too demanding for them.

Hope I made at least some sense here because I typed it pretty quickly.

 

[jd4242]

On a roots type of supercharger setup when you place vac lines pre-blower and TB you will see neither vacuum or boost. Post TB and pre-blower you will only get vacuum but no boost. Post TB and blower and you will get vacuum and boost.

You have a few choices when it comes to hooking up an aftermarket fuel pressure regulator (FPR). You can either boost reference or not boost reference it. Doing the boost reference is all about keeping the same injector delta (pressure drop across the fuel injectors) at all times during idle and accel. The reason for this is because how the pressure or vacuum acts on the fuel trying to come out of the orifices in the fuel injectors. When in boost the extra pressure pushes back against fuel pressure in the fuel system and less fuel will come out. When sitting at idle with 20in/hg vacuum (roughly -10psi vacuum) then the vacuum in the intake manifold will tend to suck fuel from the injectors.

In a non-boost referenced FPR in a supercharged vehicle your overall fuel pressure read by a FP gauge will remain at a constant psi. But the actual psi making it out of the injectors in relation to the pressure/vacuum in the intake manifold will vary. So if I set my FP to 43 psi without the car running then when I crank it and it sits at idle my gauge is reading 43 while I am actually injecting in about 53 psi worth of fuel because of the -10psi vacuum in the intake. When I get into boost this situation reverses and I will get proportionally less fuel into the intake manifold because of the boost pressure pushing against the fuel in the rails.

A boost ref FPR will ensure that whether you are in boost or vac that your pressure drop measure across the injectors (aka inside the rail before the injectors and post injector inside the intake manifold) stays the same. Your read FP on the gauge will increase or decrease of course since FP in the system is raised or lowered to compensate in a 1:1 ratio for the boost or vac the FPR sees.

As long as you know your overall FP will not exceed any internal pressure bypasses that your fuel pump might have then I recommend to boost reference your FPR if it has the capability. That way it will prevent you from running out of fuel on the top end or just putting your fuel injectors under a duty cycle that may be too demanding for them.

Hope I made at least some sense here because I typed it pretty quickly.

yea you lost mewe are using a stock fpr.i works by vac,high vac it opens and lowers fuel pressure,low vac or no vac it closes and increases fuel pressure.i didnt understand the pre blower or pre tb stuff either.after the charger where it mounts to the lower intake manifold should see vac and boost right?i would think everything on the other side(the intake side for the blades) would see nothing but vac.i would think at low rpm the air bypass would cause vac and when in high rpms the sc would be causing ALOT of vac.where does the boost gauge mount?i think this is where the stock fpr needs to mount,it needs vac and no vac(boost)

 

[jd4242]

On a roots type of supercharger setup when you place vac lines pre-blower and TB you will see neither vacuum or boost. Post TB and pre-blower you will only get vacuum but no boost. Post TB and blower and you will get vacuum and boost.

You have a few choices when it comes to hooking up an aftermarket fuel pressure regulator (FPR). You can either boost reference or not boost reference it. Doing the boost reference is all about keeping the same injector delta (pressure drop across the fuel injectors) at all times during idle and accel. The reason for this is because how the pressure or vacuum acts on the fuel trying to come out of the orifices in the fuel injectors. When in boost the extra pressure pushes back against fuel pressure in the fuel system and less fuel will come out. When sitting at idle with 20in/hg vacuum (roughly -10psi vacuum) then the vacuum in the intake manifold will tend to suck fuel from the injectors.

In a non-boost referenced FPR in a supercharged vehicle your overall fuel pressure read by a FP gauge will remain at a constant psi. But the actual psi making it out of the injectors in relation to the pressure/vacuum in the intake manifold will vary. So if I set my FP to 43 psi without the car running then when I crank it and it sits at idle my gauge is reading 43 while I am actually injecting in about 53 psi worth of fuel because of the -10psi vacuum in the intake. When I get into boost this situation reverses and I will get proportionally less fuel into the intake manifold because of the boost pressure pushing against the fuel in the rails.

A boost ref FPR will ensure that whether you are in boost or vac that your pressure drop measure across the injectors (aka inside the rail before the injectors and post injector inside the intake manifold) stays the same. Your read FP on the gauge will increase or decrease of course since FP in the system is raised or lowered to compensate in a 1:1 ratio for the boost or vac the FPR sees.

As long as you know your overall FP will not exceed any internal pressure bypasses that your fuel pump might have then I recommend to boost reference your FPR if it has the capability. That way it will prevent you from running out of fuel on the top end or just putting your fuel injectors under a duty cycle that may be too demanding for them.

Hope I made at least some sense here because I typed it pretty quickly.

ok understand this a little better.i would think pre tb would see a little vac at idle and full vac at acceleration?sounds like a stock fpr works like a boost ref fpr,just increases fp in the rail when under boost(no vac) or acceleration

 

[Dono]

Wow. Tons more info.
My boost/vag gauge is pulling from post SC. I have a nipple already installed. Ron at RPCaster had drilled and tapped a line for me.

Im not planning on running an external fuel pressure regulator. High volume fuel pump, and larger injectors. Factory fuel pressure regulator in the tank.

 

[jd4242]

Wow. Tons more info.
My boost/vag gauge is pulling from post SC. I have a nipple already installed. Ron at RPCaster had drilled and tapped a line for me.

Im not planning on running an external fuel pressure regulator. High volume fuel pump, and larger injectors. Factory fuel pressure regulator in the tank.

Do you have a returnless line?does it not use a fpr on the fuel rail?

 

[Dono]

Yup, returnless. The fpr is in the gas tank, and on the rail there is some kind of pulse smoothing unit. I've read quite a bit about the returnless system. Lots of confusion around it.

 

[jd4242]

Yup, returnless. The fpr is in the gas tank, and on the rail there is some kind of pulse smoothing unit. I've read quite a bit about the returnless system. Lots of confusion around it.

O gotca.i still dont understand them so you dont even have to worry about this then,only asked it here instead of my thread because thought it might apply to you also.i uave one on the rail so it needs to have a nipple on my lower intake manifold;(

 

[Dono]

Ya, I spent time reading on he forum. Some conflicting info, but I hope I got it. I also hope fuel will be fine, with no pain. I don't have a vac line from my little pulse corrector thingy to my manifold.
Today, I popped a hole thru my firewall and ran the wideband o2 line, and vac-boost line. I will tap my fuel rail for fuel pressure gauge when I take it off for the new injectors. I sure hope I don't mess up the threading part.

I'd like to get that wideband o2 gauge working just out of curiosity to see what my trucks currently doing for air-fuel ratio.