2.1L Big Bore Kenne Bell Twin Screw in a 3.8SC powered XR4Ti

Ghost

Registered User
You guys are not familiar with my project. About a year ago Jeramie (92Bird) convinced me to swap an SC motor into my Merkur XR4Ti. I was originally going to use Dr. Fred stage 1 heads along with the 520 cam and an MPX. After searching the forums and getting a ride in Todd Jelle's car I decided that I wanted a twin screw blower for my car. I initially bought a Whipple blower which turned out to be a 1.33L unit, which would obviously have been too small. I finally lucked out and got my hands on one of the new 2.1L "Big Bore" Kenne Bell blowers for a decent price. Now the motor build will be changing significantly. I'm planning on a 4.2 crank with the 351W h-beam rods, forged pistons, SuperSix stage 3+ superheads, 75 lb injectors and a good size front mount IC. A stud girdle will probably be a good idea as well. This is being mated to a built T56 transmission with an SC rear end complemented by a Detroit TrueTrac and 3.55 gears (those have already been in the car for the last 6K miles or so and working beautifully). I also have a Universal AEM EMS standalone for this, so tuning should not be an issue. The car should be pretty insane at about 3200 lbs.
From preliminary research the blower is capable of 20+ lbs of boost on the DOHC 4.6 motor, so it should be fun on a 4.2. I'll probably need to underdrive the blower a little bit to keep the boost levels manageable, which should (hopefully) decrease issues as far as the extreme crank snout loads being placed on the crank by a PD blower. I have a buddy with a machine shop and also have a lot of tools myself, including a Tig welder, so fabrication should not be an issue.
Anyway, here are some preliminary pics of the blower sitting on the intake. It's actually pretty compact at about 8"Wx10"Lx5.5"H:

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Have you posted this somewhere else a few months ago? I can swear that I have seen this before.
 
You've probably seen the 1.33L Autorotor thread right here:
http://www.sccoa.com/forums/showthread.php?t=101150

Amazing thing is that the 2.1L blower is not much bigger than the 1.33L unit.

BTW, does anyone know of a good source for billet fuel rails? I'm thinking that 1/2" bore fuel rails should be enough, if not I guess I'll have to step up to the 5/8" rail stock, which would be kind of close to the blower sides. I already have a 255lph FI walbro pump in the tank, hopefully that will be large enough as well.
 
It looks similar because the snout he used for the pic is off of the 1.33L blower pictured in the other thread (flaking paint). Apparently it fits for mock up purposes.

That merkur is gonna be nasty.

Only thing that would bother me is the "kenne bell" is upside down. :p

Jeramie
 
i think im confused y the bigger blower are you aiming for more boost?

The 1.33l would not have been sufficent blower for a 3.8l engine.
This is more then adequate.

I was going to bid on that blower if that was the one on ebay few last week. ;) Looks like it fits well. Why are you going with billet fuel rails. Are you having problems with the stock ones? you are supposed to cut the bypass tube and make a longer hose to connect the rails toghether.
 
Yup, that be the same blower from ebay :)
I was going to re-work the stock rail, but honestly just looking at the kinked bends in it makes me cringe. I'd rather not worry whether or not I have enough volume of fuel in the rail. I don't want the small rail coupled with high demand for fuel to cause large pressure pulses and the associated fuel pressure variations. I'll have a hard time getting the tune built from scratch as it is, I don't need to add yet another variable into the equation. Also, the XR4 has the fuel lines by the drivers side rail (they'll probably get upgraded to a larger line as well), so I would've had to run long lines and cross over somewhere behind the motor.
Billet fuel rail extrusion is only about $11 per foot and a good adjustable remote mount regulator is around $100, plus misc. fittings and hoses. It's just a cleaner solution overall. The only bad thing is that if my buddy can't mill the injector openings precisely enough, I'll need to buy the proper $130 drill bit.
Yes, I'm anal-retentive about the details, you can ask Jeramie about that one :) I'd rather spend more time and money, but have everything buttoned up top notch. There's a reason I've spent over $3K on the transmission alone.

Next question to ponder: should I cut the roof off the stock intake manifold and raise it to create a larger plenum? Seems like that will become the next restriction (judging from all of the posts about modified intakes).
 
No hood clearance to run the blower on it's side, plus the newer blowers (like mine) are vented through the snout bolt, so that may be a concern. The fuel rail clearance is not bad at all. The blower would fit with the stock rails, but like I said, I just cringe looking at them...

I called Kenne Bell about the snout - it's not bad at $299. They weren't all that helpful with regards to snout length and what their various offerings are, but when I mentioned that I needed a snout for the 96-98 Cobra kit (was just a wild guess from looking at the pics on their site) he gave me the measurement of 141mm flange to pulley shoulder, which is exactly what I'll need :)

Now I need to figure out the mounting provisions. I'm thinking of making the inlet plenum and the return plenum as one piece for mounting purposes. As far as the front, maybe I can make an A-arm like Dave's kit (unless he can sell one separately) or maybe figure something out as far as attaching the base of the snout to the intake manifold.

BTW Manny, were you the one that was modifying the intakes and raising the roof to create a bigger plenum? I might be interested in one depending on price.
 
The big bore 2.1 blower is taller then the old 2.2l it replaced. I wonder how bad it affects hood clearence. Although you dont have and SC so it doenst matter anyhow it should fit under yours. Post pics of the build as you go. I am sure others would love to see them including myself.
 
Honestly, I haven't had much time & motivation to work on the car - it's amazing what a divorce does to best laid car plans (I knew my old weird Ford was a better investment than the redhead!).

Last month I finally bought the correct snout from Kenne Bell (part# 141-12, 141mm length application is a 96-98 cobra), bought a 3.75" pulley, pulley tool etc (to the tune of $500 total or so). At first KB did not feel like selling the parts, until I gave them a guilt trip about me buying their product and expecting at least some support with replacing damaged parts and that I found it weird that they would turn away money in this economy etc.
I also got big chunks of aluminum to machine into a plenum and blower top as well as pieces to build the snout support.

I just got all of my T56 rebuild/upgrade parts, I scored 72lb injectors, bought the fuel rail extrusion and the correct injector port tool, bought a 4.2 crank, got some big valve ported heads & big cam and a whole bunch of misc. stuff. The block is currently at the machine shop getting checked over, measured and having the decks milled as well as getting line honed. Next up will be the rods/pistons, I'll be getting those from XR7Dave (as soon as I know exactly what I need).

I am hoping to have it running sometime late this year now that the project is back to life! Even after it's back together I'll have a whole lotta fun building a tune from scratch...
In other words, it's coming, slowly but slowly :) Keep your fingers crossed!
 
Just wondering why you think an EEC from an SC with all the wiring would not have been up to the task? Personally I would have went with an EEC from a 5spd 94/95 SC and you would have been 85% there with a few tweaks to the tune to match injectors etc to get started.

It would be alot easier to do that than start with something that has to be built from scratch.

Fraser
 
Last month I finally bought the correct snout from Kenne Bell (part# 141-12, 141mm length application is a 96-98 cobra), bought a 3.75" pulley, pulley tool etc (to the tune of $500 total or so). At first KB did not feel like selling the parts, until I gave them a guilt trip about me buying their product and expecting at least some support with replacing damaged parts and that I found it weird that they would turn away money in this economy etc.
I also got big chunks of aluminum to machine into a plenum and blower top as well as pieces to build the snout support.

It is one of the reasons I gave up on Kenne Bell. They just dont want to deal with you unless its on their terms. So they turn business away. Whipple on the other hand will do anything you want & set up the blower like you want. Keep posting as I for one would like to see how you aproach the problem solving. Good luck;)

Ken
 
Yeah...I like to see stuff being built too. Espically since I have two other cars to finish before I start on the 6er again.

SWS
 
I've thought about it, I was actually going to use an EEC-V from a Mustang. But then it's a hassle finding a used harness in good shape, modifying it and then still having to worry about bugs caused by a used 10+ year old harness.
I already had a brand new AEM 30-1900U universal ECU with the harness that I bought a couple years back. So instead of losing a ton of cash on that, I might as well use the built in features, such as dual widebands, EGT correction, bypass valve control, traction control etc. I'll probably use the nitrous functions to control a water/meth injection system down the road. I really did not want a MAF due to space restraints. The cost vs. benefit of switching back to the EEC just wasn't there by the time I would've bought a harness, ECU, larger MAF, a tuning tool to flash it plus I've really grown to hate the EEC-IV over the last 15 years or so - too many issues, crappy resolution, too much monkeying around to datalog.
Just my opinion I guess. I realize that even building a base tune from scratch will be a PITA, not to mention getting the thing driveable, but that's half the learning experience. I'll just have to take it a careful step at a time.

Just wondering why you think an EEC from an SC with all the wiring would not have been up to the task? Personally I would have went with an EEC from a 5spd 94/95 SC and you would have been 85% there with a few tweaks to the tune to match injectors etc to get started.

It would be alot easier to do that than start with something that has to be built from scratch.

Fraser
 
Thats cool.

But to clear up the myth about how bad the EEC-IV's are, now adays it only takes minutes to be setup to datalog, and we're talking logging hundred's of parameters in real time with the EEC (the slowest point of how fast you can datalog is not the EEC anymore but your laptop), and being able to tune it on the fly without shutting down etc. Its actually easier to work on now than ever. The EEC-IV's are also totally capable and in fact have been used to run 1500hp motors with alot of success.

Good luck, I look forward to seeing the outcome of your project.

Fraser
 
Time for an update.
I put the LS1 tailshaft housing on my Cobra T56 to move the shifter back about 3". It was not as easy as every "expert" on the various boards made it sound (including some that rebuild these for a living). The Cobra uses a longer mainshaft than the LS1. The LS1 also uses a one piece 5/6 driven cluster gear, the Cobra uses two separate gears. This means that the 5/6 splines are different between the two mainshafts. You're either stuck buying the .74/.50 LS1 5/6 gear set or cutting the Cobra mainshaft down. I chose to shorten the mainshaft. This also involved cutting a new retainer groove for the VSS rotor, which proved to be the difficult part. In retrospect, it probably would've been easier to start with an LS1 2.66 ratio tranny and put the Cobra input and mid-plate on it. I'm sure there would be some issues there.

So now I've gone through the T56 and completely rebuilt & upgraded it. Never believe a Cobra owner that tells you "Yeah, the tranny is in great shape, it shifted smoothly". I had to replace all synchro hubs except for reverse as well as replacing the 2nd & 3rd gears. That was $600 that I was not planning on spending on top of spending $800 on the rebuild and upgrade kit. This brings the total cost of the tranny/bell to $3750 (yikes!).

Onto some pics. Here's the ported MPI M90 next to the big 2.1L blower:
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Starting to mock up the blower on the engine:
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I'll need to fabricate a combined inlet/return plenum back here:
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Here's some pics from the T56 rebuild/upgrade.

Difference between the shifter locations. LS1 in the background:
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LS1 mainshaft. You think it's thick enough?
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Scary stage - the tranny in pieces. Can you see the difference in the Cobra mainshaft that's pictured here?
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Another pic of all the parts cleaned up, with fresh bearings and ready for reassembly:
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Setting preload on the main and cluster shaft. Preferable factory spec is .000"-.002" preload. High performance specs are .002"-.003" preload. I lucked out and managed to have the correct shims to set both at .003".

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Now we're ready for final reassembly:
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5/6/reverse installed:
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And the final product:
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This puts the shifter right where I want it:
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For those of you that may be considering a T56 swap, here's a couple things:

The center of the LS1 shifter is 29 5/8" back from the bellhousing/block plate face. Also, the Kooks midlength headers (as sold by SCP) will not fit with the QuickTime 5.0 bellhousing. The passenger side header will hit the starter. I believe the starter is higher up on the 5.0 bell compared to the 3.8 specific bell. Just a heads up.
 
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