Stroker/M90 Supercharger;)

[seanyb505]

I've decided on building my stroker. I just bought connecting rods from ebay, and I'm thinking about whether I should wait until I have all the parts to buy a crap car until the new engine is road ready, or buy a junkyard engine to build while I drive the Jeep. So while combing my local U-Pulls, I found several candidate 4.0 engines. One place said 303 for an engine, and the place next to it said about 250. When I got my answers, I went rumaging cause you never know what cool stuff you'll find. Like and M90 supercharger off a 94 Tbird SC. SWEET!!!!!!!!!!!!!!!!!! I ran up to ask the price, it was nice, so i ran back to get it. about 20 minutes and 66 dollars later minus some piping, I owned a nicely rotating supercharger. Now I have some questions- I would want to get a 99 engine, but it's at the expensive place. Would a 91-96 lack anything I would want in a stroker? I have a 99 intake so it's not an issue. Second, how tall should the tent I'm pitching be over this SC? Would I be better off selling it or should I keep it and fab up some stuff for the stroker in the future. I love the wealth of information on this site, so I'll be asking questions and keeping you guys updated on my progress over the next 2 years or so


Im crapping my pants thinking there's a supercharger in my living room ready to do what ever I want it to!!!!!!!:laugh3:

[Beatjeep]

I've decided on building my stroker. I just bought connecting rods from ebay, and I'm thinking about whether I should wait until I have all the parts to buy a crap car until the new engine is road ready, or buy a junkyard engine to build while I drive the Jeep. So while combing my local U-Pulls, I found several candidate 4.0 engines. One place said 303 for an engine, and the place next to it said about 250. When I got my answers, I went rumaging cause you never know what cool stuff you'll find. Like and M90 supercharger off a 94 Tbird SC. SWEET!!!!!!!!!!!!!!!!!! I ran up to ask the price, it was nice, so i ran back to get it. about 20 minutes and 66 dollars later minus some piping, I owned a nicely rotating supercharger. Now I have some questions- I would want to get a 99 engine, but it's at the expensive place. Would a 91-96 lack anything I would want in a stroker? I have a 99 intake so it's not an issue. Second, how tall should the tent I'm pitching be over this SC? Would I be better off selling it or should I keep it and fab up some stuff for the stroker in the future. I love the wealth of information on this site, so I'll be asking questions and keeping you guys updated on my progress over the next 2 years or so


Im crapping my pants thinking there's a supercharger in my living room ready to do what ever I want it to!!!!!!!:laugh3:


IN terms of the superhcarger the M90 unit is a direct mount unit as it mounts in place of the intake plenum. You will need some pretty slick fab work to fit it I would imagine. Not sure how much boost it will put out if you need to think about fuel delivery issues and tunability. You also cant intercool it and its going to get MIIIIIGHTY hot under the hood of your xj.

[seanyb505]

As of now Im thinking it will take the place of my AC unit. I havent used it in the last two years and I think i could make some sacrifices for some more fun. So for location and bracket fabbing Im not that concerned. An intercooler is something I would have to think about, and Im coming to the realization there is going to be a lot of piping. A new fuel pump would definately be necessary, and since it will be a stroker new injectors will be needed anyway, it's just a question of which ones. Is it necessary to mount the throttle body before the supercharger? XJ Armor has the SC in place of the AC and it looks like the TB stays on the intake manifold. No matter what happens, Im still stoked at this moment to even be building a stroker let alone have a SC involved.

I believe nothing is impossible at this point.

[tealcherokee]

As of now Im thinking it will take the place of my AC unit. I havent used it in the last two years and I think i could make some sacrifices for some more fun. So for location and bracket fabbing Im not that concerned. An intercooler is something I would have to think about, and Im coming to the realization there is going to be a lot of piping. A new fuel pump would definately be necessary, and since it will be a stroker new injectors will be needed anyway, it's just a question of which ones. Is it necessary to mount the throttle body before the supercharger? XJ Armor has the SC in place of the AC and it looks like the TB stays on the intake manifold. No matter what happens, Im still stoked at this moment to even be building a stroker let alone have a SC involved.

I believe nothing is impossible at this point.

start researching.... your in over your head if you go at it now.

now only do you need new injectors, you need some sort of fuel management that understands boost, you also need something to pull timing as you boost. and OHHH so much more :D

(i have a turbo stroker in the works :))

[seanyb505]

That's why it's still sitting on my living room floor. If I didn'dt think I was in over my head I would have put it on already. I knew different higher flowing injectors would be necessary. I have no clue on where to even start looking for control of this system. The M90 has a bypass valve, to equalize pressure during non-boost times(I think? Correct me if I'm wrong). I am by no means educated on this topic. My roomates want me to put it on tonight with duct tape, I at least know this isn't a good idea and more work needs to be done. Which is why I would like to build a stroker that would accept pressure. If anyone wants to school me on this, I'm all ears to new info.

[Pro Stock John]

I dug around looking for some pics before I made any comments:

http://www.bluegt.com/blower_03.jpg
http://www.pfyc.com/mm5/graphics/new/wb3038.jpg
http://www.britishv8.org/MG/JimBlackwood/EFIpassfront.jpg
http://www.britishv8.org/MG/JimBlackwood/EFIpassrear.jpg

[Pro Stock John]

So I don't have any experiences with those kinds of superchargers, but it looks to me like you need a base of some type since you will be mounting the supercharger + base instead of the factory intake manifold? Is that correct.

Issue 2 and 3 are the pulley setup + tensioner, and then the air intake setup.

It can be done but someone is going to need make some brackets and work on the pulley setup. I think the fuel side of it would be the easiest part.

I had a custom centrifrugal supercharger setup on my 98 turbo'd formula, pics on page three of my car site:

http://psj.ls1tech.com/gallery/main.php?g2_view=core.ShowItem&g2_itemId=10&g2_page=3

So the big things I think you need to figure out, before you start screwing around, is where the blower needs to sit in order for the blower pulley to line up with whatever belt will be driving the supercharger. Phase 2 will be figuring out where the tensioner pulley will sit.

What you might want to do (assuming my comments about the intake manifold are right), is take a 94 t-bird intake and a stock jeep intake, and look at how you can weld the parts together.

[seanyb505]

As of now my plans are extemely preliminary. I know better than to try to put it randomly somewhere. I think the best place would be where the AC is, and i know a bracket will have to be built.
http://rides.webshots.com/album/325277378UlfWEd?start=12
Someone on here started to mount one, but I guess they ended up selling everything. I think I'm going to try to go off of what I see from the pictures. This isn't being built next month, or probably within this year. I need to research and find out everything I can to make this work.

Im not to worried about physical location of the blower, but more about the computer, and fuel system delivery. I have no idea what kinda of demands are going to be created. New injectors, FPR and higher pressure fuel pump are a must, Im just not sure where or what to start looking for.
Also I need to figure out how to either A.) Find a way to mount the 4.0 TB to the setup (bored, obviously) or B.) Find a way to make all the Jeep computer sensors fit the Tbird TB which mounts to the piping I have. Donor Tbird was a 93 btw.

Also it looks like all the electrical components will need to be moved from the passenger side of the engine bay, probably to the driver side, since the air intake(not manifold) will be moved to the passenger side.

Right now I know Im too far in over my head to start. The only way to fix that is to learn more. I dont see how this cant be possible with time, money and knowledge. I currently have more time than money and knowledge combined and Im in no hurry.

First things first though, the supercharger will not be put on my current 4.0 engine. I will be buying a junkyard engine and building it to a 4.7. Im hoping.

Any and all input is desired!

[seanyb505]

I know my compression will need to be lowered to make the engine more boost ready, will I need to plan ahead for lower compression pistons? If so, what characteristics will I need to look for. And does anyone know why Summit lists pistons as the same company but one with standard measurements and one with metric and the standard measurement cost 11 dollars more? Whats a good place for overbore piston rings? Ill be looking to go .030 or .060 depending on condition of the block. Will I need to take boost into account when purchasing piston rings?

Thank you in advance!

[cnidy1230]

check ou this thread will help with some important specs you will need. My supercharger is getting close to complete and will post pics asap. my supercharger will be right on top of my intake since i hae a costum 5 inch cal induction hood. good luck!!! http://www.naxja.org/forum/showthread.php?t=103942

[seanyb505]

It's very encouraging to finally see people trying this with the M90. I had looked but it seemed that people didnt care or were going with turbos. I would, but I dont have a turbo I have a supercharger, and a Jeep. I work with what I have.
Keep me posted on any further info!

[seanyb505]

Ok so I'm looking at rod and main bearings. Not sure what to look for, I've read on here to get ARP 112-6001 rod bots, but what about bearings? Do I need rod bearings even if the rods have been reconditioned? If I do is there a specific brand/ part number I should be looking for? Ive seen Clevite part MS-1947P thrown around threads about building strokers, but are these for a specific year of block, or will they fit any 258 crank in any 4.0 block? I fully acknowledge my lack of intelligence or common sense on this subject and have come looking for help.

[seanyb505]

check ou this thread will help with some important specs you will need. My supercharger is getting close to complete and will post pics asap. my supercharger will be right on top of my intake since i hae a costum 5 inch cal induction hood. good luck!!! http://www.naxja.org/forum/showthread.php?t=103942

I actually remember reading that thread a couple months ago, do you know if the clockwise rotation of the 4.0 serp belt drives the pulley in the right direction? I have not been able to confirm the nessecary spinning direction of the pulley on the blower. Im starting to draw up some designs to mount the M90 in place of the AC based on what Ive seen around. Also did you ever come up with a solution to an intercooler? And how wide is the highest part of the cowl induction hood? I know im going to need more room even if I swap the AC.

[Pro Stock John]

If the stock compression is 8.x:1 like I have read, that is already pretty boost friendly. I'd get something running with the stock engine and build a stroker on the side. With the stock engine I would run new valve springs since you'll need more spring pressure for the supercharged or turbocharged setup.

[seanyb505]

I thought about that, but I have too many miles on my stock engine for me to feel comfortable about supercharging it. I may do that if I get impatient with the stroker build, but I just figure Ill build the stroker with the blower in mind. I drew up some rough belt diagrams and a bracket to replace the AC.

[seanyb505]

Does anyone know if 30# Ford injectors will physically fit a 4.0? I chose 30# because thats what comes stock on the Super Coupe that I got the SC from. Is that too high or should I stick with just the 24# for the stroker?

[jeepinwi]

Yes, 30# injectors will fit perfect on the Jeep 4.0 They will even use the same connector as pre-1999 4.0's I think 30# would be a good injector to run with Forced Induction. 24's are theoretically only practical for about 230hp. 30's are good for about 290 hp.

[Pro Stock John]

I think 30's are good to 400hp (at the crank) at the right fuel pressure actually.

[seanyb505]

How high of fuel pressure should I be running and is there a fuel pump for this application or would it have to be made custom or something?

[seanyb505]

Does anyone know the forumla to calcute boost or to calculate a supercharger rpm given the engine speed and crankshaft pulley diameter? I know my SC make around 11 psi on the 3.8 V6 it came from, but I think since it was smaller and probly turning higher rpm I wont be getting near that. Id like to know what to plan for.
Thanks in advance!

[gbaronetXCR]

That was my bracket you refered to... Sold the blower and bracket a member here.

Just think about how you will feed the intake.
Watch the pulleys, for blet wrap on the blower and clearing the waterpump tube, that's why I used the two pullies on the drop down.
The Xk, is tight under the hood, YJ would be much easier.

Use the main head bolt locations the AC units uses as well.
I might have been overkill on the steel, but did not want the torque to flex it around.
good luck

[seanyb505]

yeah I spent a couple night looking at your designs, I dont have a problem using steel, it makes me feel better about the security of the system. Do you know what direction the pulley spins? The belts on the 4.0 go from left to right on top(clockwise), will this turn the blower in the right direction? Ive asked around and researched it but everyone just kinda ignores it. I dont have a problem cutting the hood or buying a hood scoop to make it fit.

[fitbmxseries1]

http://www.thirdgen.org/techboard/power-adder/277250-eaton-m90-finally-blowing.htm
not sure if you need to sign up to view that page but this guy put an m90 on an TPI engine and just made some plates and brackets and mounted the supercharger off to the side of the engine.it might help with some ideas. he ahs another page and a video of him drivng it but i cant find any of it.

[tealcherokee]

youre going to need 65ish lb injectors to run any decent amount of boost into a stroker at a normal (39psi) amount of fuel pressure, youre also going to need a high volume fuel pump

[seanyb505]

A new fuel pump would definately be necessary...


Yes I know I will need a higher volume fuel pump. 65# injectors seems waay to high; the Tbird only runs 30#s. I know my application will be larger by .8 liters, but I dont see how that should double the rate of the injectors. Define decent amount of boost, because I know you're bent on running 15 psi with a turbo. Im not. Ill be happy with 6-7psi.

[tealcherokee]

Yes I know I will need a higher volume fuel pump. 65# injectors seems waay to high; the Tbird only runs 30#s. I know my application will be larger by .8 liters, but I dont see how that should double the rate of the injectors. Define decent amount of boost, because I know you're bent on running 15 psi with a turbo. Im not. Ill be happy with 6-7psi.

for the 15psi into my 4.5L im going to need 70lb injectors @39psi.

4.6L stroker 6-7psi atleastt 45lb injectors

[Pharaoh XJ]

Does anyone know the forumla to calcute boost or to calculate a supercharger rpm given the engine speed and crankshaft pulley diameter? I know my SC make around 11 psi on the 3.8 V6 it came from, but I think since it was smaller and probly turning higher rpm I wont be getting near that. Id like to know what to plan for.
Thanks in advance!

boost = (pulley ratio x 14.7 x SC displacement / half engine displacement ) - 14.7

in case of an M90 on a stock motor and 6 psi
(ratio x14.7 x 1,484 / 2000) - 14.7 = 6
then ratio of SC pulley to crank pulley = 1.89:1

[gbaronetXCR]

The M90's on the 3.8's run 6-8 psi., that's where I grabbed my pulled from, an old Bonni ssei.
The blower producing air spins clockwise.

Using the ford Sc TB intake for the blower. Planned to use the bypass valve by feed it from the boosted side pipe. It would pump boosted air back into the blower reducing belt drag. Search around it's well documented.
The other nice element of this setup, it not needing to run a blow off valve because the TB is on the low pressure side and not running a blow through style, like external SC or turbo's. Keeps it simple.
I talked with a local hotrod shop about injectors. You should look in to a rising rate fuel regulator that would use boost refferance. (4:1) You would be ok with your stroker and larger injectors, but add boost you need to manage the fuel some how. With 6-8 psi the fmu was a decent bandaid. More than that you need serious engine management that would deal with timing, and would want more indicators.
Considering an intercooler when planning your boost exit even with the low boost levels. You might loose up to 1 psi across your intercooler, but increase your Hp by dropping 100-150 degrees in intake tempurture.

My refferance is a friend that put on a vortec SC from a 5.7 TA onto his 928.
http://norcal928.org/DIYSC/
Stock the 928 was seeing a 13.3 at the track at 118, yeah bad 60ft.
After the blower a 12.6, add intercooler 12.1 in mid july.
Have a GTP now, first change this year will be an intercooler.

[Pro Stock John]

I'm running 96lb injectors at 45 base fuel pressure to make 867rwhp at 24psi in my 98 Formula turbocharged setup: www.psj.ls1tech.com (http://www.psj.ls1tech.com)

I've made 470rwhp with a 422ci + 38 lb injectors at the LS1 base fuel pressure of 57psi.

I don't see why you would need more than 30 - 36 lb injectors to make 350-400 hp.

[seanyb505]

boost = (pulley ratio x 14.7 x SC displacement / half engine displacement ) - 14.7

in case of an M90 on a stock motor and 6 psi
(ratio x14.7 x 1,484 / 2000) - 14.7 = 6
then ratio of SC pulley to crank pulley = 1.89:1

I know there are several formulas to calculate boost and other variables. I cant piece together right now the base figures i need to work those formulas. That one works if you know the psi the blower will put out. I was looking for something more along the lines of using engine speed the diameter of various pulleys (crank and blower in particular) to determine how much psi it will run. I know for a fact that Supercoupe owners with boost gauges record about 10-12psi. Smaller engine, higher RPMs. The formula gives a different pulley ratio when you change the boost, is there a way to use the pulley ratio to determine boost? If I could do that I would be able to determine the projected HP and then find out the right size injectors.

[tealcherokee]

I'm running 96lb injectors at 45 base fuel pressure to make 867rwhp at 24psi in my 98 Formula turbocharged setup: www.psj.ls1tech.com (http://www.psj.ls1tech.com)

I've made 470rwhp with a 422ci + 38 lb injectors at the LS1 base fuel pressure of 57psi.

I don't see why you would need more than 30 - 36 lb injectors to make 350-400 hp.
first of all, can you plug your pics a couple more times, i dont think everyone has seen them.

also, you have 8 injectors, we have 6

[Flash]

He is vary proud of his accomplishment just as you will be when you have finish your, and will want to share with any one how would want to.....click and see.

I haven't added any thing to this thread............well because this is over my head, mostly, but vary interesting just the same.

As far as the question that you have ask many time, and every one has avoided........this is my take!

Almost all (all that i now of)of the automotive eng, turn counter clock wise(sitting in the drivers seat.) and the jeep in no exception to the rule!

Now if the SC pulley has groves in the pulley, it will turn in the same direction and the crank. If the SC pulley is smooth(driven by the back side of the belt, it will turn in the opposite direction!

Flash.

[seanyb505]

THANK YOU! I have having concerns about how i was going to run the belt around the pulley. I cant actually make brackets for it yet, but Im getting some designs down.

[Flash]

THANK YOU! I have having concerns about how i was going to run the belt around the pulley. I cant actually make brackets for it yet, but Im getting some designs down.

:thumbup:

[seanyb505]

Ive made some modifications and purchases for my project this week. First off I replaced my 3.07 8.25 with a 3.55 8.25. Best performance result of any mod yet. Today I cut one coil off the front springs, lowering the front about an inch to match the sag in back. While I was at the junkyard getting a new cluster and speedo sensor for the new rear end, I saw the head sitting on the ground, all the dirty work done and ready for the picking. Ive heard that the HO heads have better flow rates though and this one was from a 97. Can anyone verify this, and would it even matter considering any head I get will be ported and polished?

[seanyb505]

I haven't added any thing to this thread............well because this is over my head, mostly, but vary interesting just the same.
Flash. lol Same here! Ive been trying to get my research on and gathering parts before I attempt to put anything together.

[Flash]

Ive made some modifications and purchases for my project this week. First off I replaced my 3.07 8.25 with a 3.55 8.25. Best performance result of any mod yet. Today I cut one coil off the front springs, lowering the front about an inch to match the sag in back. While I was at the junkyard getting a new cluster and speedo sensor for the new rear end, I saw the head sitting on the ground, all the dirty work done and ready for the picking. Ive heard that the HO heads have better flow rates though and this one was from a 97. Can anyone verify this, and would it even matter considering any head I get will be ported and polished?


what year of xj is this 97 head going to be on?

Flash.

[seanyb505]

Both of the jeep are 97s. It was basically my jeeps twin in the junkyard down to the color.

[Flash]

Both of the jeep are 97s. It was basically my jeeps twin in the junkyard down to the color.

sooo you didn't just buy the rear. You bought the hole jeep?


Flash.

[seanyb505]

lol no I pulled the rear end, some front body work, gauge cluster, and the speedo sensor gear and the head from it. So basically I bought a lot of it

[Flash]

sounds like you should have bought the hole thing:D

Renix go up to 91.... and 92+ are HO's so i would say that a 97 on a 97 had out to work just fine.;)

[BBeach]

Renix is 87-90, 91+ is high output.

[BBeach]

Look on Dyno's site, he's got a lot of info about the different years and heads. http://www.jeep4.0performance.4mg.com/tech_specs.html
Year............Casting No
1987-90......2686
1991-95......7120
1996-99......0630
2000-01......0331
Different heads for Renix and H.O., then OBDII xjs from 96-99 then the notorious 0331 head.

[Flash]

Renix is 87-90, 91+ is high output.
^
. .



Yes, you are correct! sorry about that,:twak: my bad:worship:


Flash;)

[seanyb505]

Look on Dyno's site, he's got a lot of info about the different years and heads. http://www.jeep4.0performance.4mg.com/tech_specs.html
Year............Casting No
1987-90......2686
1991-95......7120
1996-99......0630
2000-01......0331
Different heads for Renix and H.O., then OBDII xjs from 96-99 then the notorious 0331 head.Yeah I was cheaking that out this morning, it seems all that changed was a water temp port on the corner. Cant wait to start working on this thing!