Starting a T build. Putting the horse before the cart.
Hey Guys, I have this dream of building a T-bucket. A nice & low, big attitude, exposed engine roadster that will be different then others. Simple frame, T-body with turtle deck or Track-T body. Jaguar independent rear end. Manual trans and of course my own home built powerplant:
I present the late 90's BMW 4.4L V8 shortblock.
Shown here with Raceware head studs, as you'll find out why in a bit:
Also picked up, a complete early 90's BMW 4.0L V8 to sacrifice it's heads, double roller timing set up and misc hardware.
Time to grab some measurements. @ TDC the pistons sit +.025" above deck. I also founf the pistons have a slight dish to them and found roughly 4cc of volume in the piston tops.
The only readily available MLS head gaskets available for the application come in a 1.74mm compressed thickness.
The heads are back from machine shop rebuild:
Measured roughly 52cc of volume from every chamber.
By my calc, 92mm bore, 82.7mm stroke, +.025" piston height, 4cc dish, 1,74mm head gasket, 52cc combustion chambers. I come up with roughly 9.6:1 static compression
Heads torqued down. New timing guides. Intake manifold adapter bolted in place.
Intake manifold adapters? For what you ask?...getting there.
Double roller timing chains:
Mocked up with the belt driven intake manifold. An Eaton M112, water to air heat exchangers, intake manifolds & injection from a late 90's Jaguar XJ8.
Bolting on timing covers and front end:
Just recently degree'd the cams; using the BMW cam alignment tools I've found that Bank1 was 2 degree's retard of Bank2. I liked the Bank2 cam timings better so I re-adjusted Bank1 to match.
With both banks now all using the same cam timing events I've measured:
@.001mm: 240° / 240° - 108° ICL / 108° LSA
@ 1mm: 211° / 206° duration.
.380" intake lift / .370" exhaust lift.
Adding some color:
I plan to mate this engine to a BMW native Getrag 420G 6 speed manual trans.
That's where I'm currently at. On a parts hold as little bits and pieces come in. Thanks for checking out my build. I'll be back with updates and to talk about the plan for EFI management.
Welcome to HR.com. Keep up the great work. You've got me impressed and I can't wait to see more.
I'm impressed. Nice work kid....:thumbup:
Very very nice! Certainly something very different from a SBC. Keep us informed on the build.
Wow! ...Just wow.
That's all I've got.
a fantastic start
but u need to look at the body. how tall are u ??? buckets don't have a ton of leg room and a clutch is a pain. 2 peddles and a steering column within 12in space. now they do make extended and wider bodies. i would not go with independent front susp. like an "A" arm. they just don't look right. a bucket usually weights less then 2000#. so u don't need a ton of power, but oh what fun smoking both tires have.
wiring.. don't put fuse box under the seat, affix to fire wall. u will get caught in rain and a box under the seat and water.... well...
master cyl.. locate under the seat with an ext arm from peddle and cut a hole in floor to access the top of m/c.
locate battery and fuel tank (10gal) in rear of deck
and if your not tall enough to throw your leg over body, door is needed.
ok that'll keep u going or thinking for a while.
T buckets are cool but only slightly more practical than a Motorcycle. That's coming from a guy who lives in northern New England. I've come to really appreciate roll up windows and a roof. Other opinions will vary.
Thank you for the support and positive feedback.
I totally understand how uncomfortable a T can be, especially for a 6'1" 220lb guy like myself. As a kid a fenderless roadster was the definition of cool hot rodding and it stuck with me, Although they are out there you don't see them at cruise-in's as much anymore, becoming rare makes them cooler for me. And sometimes they are put together quite goofy.
I'd imagine the 3 pedals, brake master & clutch master would all be frame mount. Electronics, Fuse block, computer, MSD boxes would be interior firewall mount. I've got my eye on a set of fabricated bomber style seats.
For steering, as much of a laid back tilt angle would be most desirable. I've seen some of the vertical mount columns & wheels in T's and have thought..."How do you drive it? Like one of those spin tea cup rides at the fair?" There is a photo of a Track-T that has the steering pitman arm come out of the side of the body which I thought looked pretty cool and gets the steering gear out of the footspace. I'd imagine the high up mounted steering gear is on a roll-bar type loop as I don't think they bodies are strong enough to support the gear.
Despite the independent jaguar rear end, the front would be traditional solid axle & control arm/wishbone. Wouldn't want to ruin that classic front end look. I'm even debating front end Moon tank.
On to engine to engine management: I've been tuning automotive EFI for years, mostly GM systems for Silverados & Vettes. I've taken the past couple of years to learn the BMW obd1 Bosch Motronic hex-code and how to tune those systems.
Although educational, interesting and sometimes fun. The OBD1 Motronic system is over engineered with to many unknown variables in the computer code that when focused on a performance application it becomes unpredictable.
I decided to start focusing on standalone EFI systems, but some of the initial costs of name brand systems were prohibitive for my personal budget.
Then I stumbled across a standalone EFI system that is completely DIY, opensource, and uses a readily available controller known as the Arduino. Specifically an Arduino Mega2560. The system is called Speeduino. It uses TunerStudioMS software (same as Megasquirt) and best of all the price is amazingly easy to handle coming in at around $160 for the EFI board and $50 for a genuine Arduino Mega 2560 ($20 for knockoff's).
The EFI board has a built in MAP sensor capable of up to 21psi of boost, and the tuning can either be Speed Density algorithm (RPM vs MAP) or Alpha-N (RPM vs Throttle sensor) tuners choice. For the boosted application Speed Density is the wiser choice.
Speeduino runs in 4 channels, it has four ignition logic level (+5v) outputs and 4 injector driver outputs. The unit can drive injectors directly, ignition coils need an external coil driver to convert the +5v logic out into a high load 12v ground to coil.
With only 4 channels available it means a V8 would be run in waste spark and semi-batch fire injection.
Looking at my BMW shortblock before the heads were bolted on we can see the paired cylinders (Cyls 1-4 bank 1 on the left, cyl's 5-8 bank 2 on the right)
Paired cylinders: 1 & 6, 2 & 8, 3 & 5, 4 & 7.
When one cylinder is on it's compression stroke the other is on it's exhaust stroke.
The Speeduino fires it's four channels sequentially 1 thru 4 so it's up the installer to wire the channels to the firing order of the engine. This BMW M62's firing order is 1-5-4-8-6-3-7-2.
The EFI would get wired:
Channel 1 - Cyl's 1 & 6
Channel 2 - Cyl's 3 & 5
Channel 3 - Cyl's 4 & 7
Channel 4 - Cyl's 2 & 8
I've got the system installed in a car that has a similar engine platform as this build, a 1995 BMW 540i with an M60B40 4.0L V8. On this one I opt'd to run waste spark coils and ignition leads instead of individual coil on plug.
Speeduino allows the tuner to program in the engines native sensors, the coolant, Intake air temp, crank & cam sensors, TPS can all be original to the car/engine. You also program the EFI to recognize the engines crank reluctor pulses. In the case of this BMW it's a 60 tooth wheel, minus 2 teeth with a 60° advance missing tooth offset.
The software has some cool built in tools that will automatically build a base VE map to get the engine running, then once it is running the software will make live changes to the map based on wideband 02 input. The system is pretty slick.
There is even an online tool that can make you your ignition timing map based on engine specifics.
here's a short video I made of the first fire-up and test drive after install in the previously mentioned car:
Another thing I've been playing around with is a digital dash using a RaspberryPi that communicates with the Speeduino for live engine data monitoring.
My standard gauges:
I also quickly threw together a more Hot Rod looking digital dash too:
The raspberrypi can also utilize a gps sensor and a gauge for speedometer could be added, as well as a fuel level sender and oil pressure.
Very impressive Mykk. Where are you located? Would like to know more about the Raspberry Pi dashboard. Can it be hooked to the ALDL on an OBD II car and display a full dash? Thanks, and keep us updated please.
That is some kind of KOOL I would love to have that type of setup for the bucket I'm building - I am not 6-1 but I built my own body ( scaled off of a 22 dodge) to fit me - Glass over a tube skelaton so I could make it a bit longer than normal - Pics on my profile - Keep us posted - I really like it - jaxx
Always good to see projects like this. Of course the electronics are way over my pay grade..
I would suggest you order a set of 32 rails for the chassis..makes life a bunch easier on that part. I am building my body from scratch from all metal and that is all the adventure I need right now..
I've found, online, the frame I want use for the build. Just need to save my spare pennies to place the order.
I figured the unique, dare I say futuristic, look of the frame would compliment the drivetrain. I like the drop section for the body to retain some more foot space without channeling the body. The builder says he's already got one with a drop tube to for the T front suspension and leaf.
Ultimately the deciding factor will be what is available at the time of purchase, but I've really got my heart set on this one.
Although I still very much plan to use the jaguar rear end I need to investigate it's limitations and pitfalls, like at what power levels does it decide to peace out and what gearing ratios are available so I can use those oversized 32 x 17.5x15 Mickeys
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