StephT

I've been reading here for ages, but never been much of a poster. Anyway, I'm looking for some advice on fitting 2006 CBR600F4i ITBs to a 1200 motor out of my 1978 1st gen Civic. I've spent a lot of time and money working up to the stage where I can convert my 1200 over to fuel injection for the street.

A quick introduction... I really love building my own stuff, and always start off by creating CAD models using SolidWorks, which I was trained to use back at uni/college when I was studying for a degree in Industrial Design. For my first big project I designed and made my own 4-2-1 header and exhaust system. It was heavily influenced by all the other 4-2-1 designs, so I'm not trying to claim I invented the 4-2-1 header, just that I tailored the concept to fit the 1200 without the usual compromises involved in a lot of one-off designs, like not maintaining smooth bends, but rather fudging them together to make it all 'fit' together. Because I designed it in SolidWorks, I was able to experiment and adjust until I was able to obtain tangential direction changes using the best paths, and then follow the design by printing out all the 2D sections and piecing them together, all the time having a 3D model on my laptop next to me, so I could rotate the model in any direction, and check I was doing it right. For materials I used mandrel bends in stainless for the whole project, and had the header plate and secondary flanges laser cut from 10mm 304SS. In the end I built the entire exhaust from the manifold all the way back to the tailpipe using a MIG welder, cutoff saw, 98.5% Argon+ 1.5% Oxygen gas, and 318LS wire. From the outlet of the secondaries to the back of the car I did it the old fashioned way, by building it on the car, or rather on and off the car, going back a forth to keep checking before I did the welding on the bench or garage floor.

Anyway, before I move on to the ITB project, I'll post a few pictures of the header...

To build a good sized resonator for the mid-section of the exhaust system, I took my original Suzuki SV650 muffler and gutted it, ran a 1-3/4" stainless perf tube through the centre, stuffed it with steel wool, cut some new end plates, and welded it all back together, and polished it back up.





Here's the header...









The muffler which was a Genie Mufflers turbo muffler that I cut open, shortend, replaced the packing with stainless wool, and welded back together again.












OK, I'll post another time with all the details about the 1200 ITB project.

To be continued...

StephT

So for the ITB project I picked up a good set of CBR600F4i ITBs with the rubber manifold couplers off eBay. The bike was a 2006 model which supposedly had less than 10,000 miles on it. From the condition they were in when I got them, I kinda believe it, as they actually looked almost new. I barely had to clean them at all, but I did spend some time with Autosol polishing the wax fast idle unit, and the fuel pressure regulator.



From there I got down to the business of modelling the TBs in CAD, but I only included enough detail to allow me to design the runners and intake manifold. For the intake manifold I didn't want any abrupt angles, like a lot of designs I've seen where the shortest possible path was achieved, but at the price of introducing turbulence and flow restriction issues, or what I like to call, flow-dynamics 'no-noes'. The one issue I'm most concerned with is the injector placement, as leaving it in the TB positions it 65mm away from the head, and I'm not overly keen to weld injector bungs up further and go through all the issues associated with making an injector rail. OK, that's not such a big deal, but I'm not sure it's going to provide any real gains, and I came across an interesting piece of information (threory?) yesterday, where it was stated that older engine relied on the intake being a certain length to tumble and mix the air and fuel together, whereas newer designs have things like swirl created in ports, and twin swirl combustion chamber TSCC (Suzuki), etc. So in that case, having a little length in the intake manifold may be a necessity for a 8-valve 1970s 1200 motor like mine? Anyway, this is the CAD model I came up with, along with the mandrel bends in aluminium, and the shorty velocity stacks I've purchased for the project. I'll be machining the manifold plates on a CNC mill.

StephT

For this project I also bought a MegaSquirt MS2 V3.0 in kit form, which I've half assembled at this stage. I also bought a bunch of other parts needed, like fuel pumps, both low and high pressure (I'm going to need a surge tank), a large Fram canister fuel filter, MSD coils (2 in 1 for Dodge Neon waste spark ignition) and super conductor lead/wire set, plus; air, coolant, and oil temp sensors, oil pressure sensor. I also bought the main wiring harness from the CBR600F4i so I could get all the plugs to use for connecting the MegaSquirt harness to the injector wiring harness, plus is came with 4 12v relays, a minature fuse box that will come in handy for the installation. I really want the job to look professional, so that's why I bought the F4i harness, because the plugs on the injector harness are not something I've even seen before, much less something you could pick up at a parts counter, plus it was $30, so a bargain with all the relays and fuse box included. I'm also using the F4i thermostat housing, which is perfect for what I have in mind, because I have to bring the coolant out from the head in 2 hoses, instead of the one large one on the stock Civic manifold, and the F4i thermostat housing lends itself real well to adding these on, and it also has the outlet/inlets for the wax unit coolant supply, and a temp sensor installed, so overall it will save me a lot of fabrication and headaches, as I know it suits the intake assembly and feeds the wax unit without having to worry about complications. Hopefully that made sense!





So anyway, I'm looking for advice, comments and such, and seeing I did 95% of my research reading posts from this forum, I figure what better place to take further advice from.

Thanks,
Steph

StephT

A little more info on the car/engine. I bought the car 6 years ago and have pretty much replaced everything on it, all new suspension and brakes, new paint, interior was immaculate, so left it alone, but added a few accessories, like an original Civic 8-track player that was made for Honda by Pioneer, roof console with map light and clock. It's been pretty much fully accessorised with all that were available. The 8-track I found new still in the box, with a picture of the 1st gen Civic on the front of the box, so I had to keep the box! I also upgraded the intake to a dual Keihin CV intake assembly off an 83 Civic S, which was the high performance offering from Honda at the time, much like the RS was on the 1st gen Civic, in fact the manifolds are identical, and the carbs are the same size. The RS carbs were almost identical to the GL1000 Goldwing, and the carb kits are more or less interchangeable, and the Civic S carbs were near identical to the GL1100 Goldwing, and I actually used a couple of NOS GL1100 kits I found to rebuild them. I did change the air cleaner though, to a much less restrictive design using a much larger paper filter (filtration is important to me, as I live in a dusty area). I also have an original as-new RS cam I bought from an auction in Japan. The guy had used it to run in his RS 1200 back in the 70s, just before he had Mugen fit an MS2 kit to the car (quad carbs, cam, suspension and exhaust). I have all the parts for a rebuild, but at present the motor is still strong, but I've collected them over the past few years because they're getting harder and harder to find. It was only last month when I found the last part I'd been searching for, a new oil pickup screen. For the rebuild I'm building a stroker engine, where we're dropping in a 2nd gen Civic crank and rods I bought a while back which'll add an another 100cc. At present I have a set of 2nd gen Toto pistons (higher dome than EB3 pistons) and NPR rings, which with a little shaved off the head give a compression bump to 10:1. I've been looking for a set of ED1 1500 Civic pistons which allow you to overbore the bores by 2mm over standard and bump it up to 1400cc, but they are rare as hens teeth, so I may never find them in time.

The reason I decided to go ahead with this project, other than the fact I've been thinking about it for ages, is because a friend did it to his 1200 and I caught the bug from him, plus peer pressure played a part too! He used GSXR1000 ITBs and had Don Flores build and tune the engine for him. He says it put out 140 on the engine dyno, which is pretty much the highest all-motor 1200 output I've ever heard of, with 110 being pretty much the max with carbs, although I have heard 120 mentioned before, but nothing to back it up with. My friend went all out with his motor, and even built a ram-air feature like motorcycles have. On the later 1st gens there was a WRX-style hood scoop that fed into a cavity in front of the windscreen to provide air to the cabin, so when he made a new glass hood recently, he made the opening even higher to get more air pressure building up in the air box he designed and fabricated, and I'm really looking forward to hearing how much it increases VE when he looks at the ECU logs after the next race. The 140 on the engine dyno would have to get at least an extra 10 from the forced air intake, and it's a BIG scoop, so I suspect it may even be higher. His motor lives in the 5500-8000rpm range, but I want mine to launch off the mark at much lower revs, and be totally streetable. It's going to be a bit of a sleeper, and that's why I've gone out of my way to make the exhaust quiet, but not to the point of sacrificing HP, well hopefully not anyway, because there's definitely not enough to do any sacrificing with! :lol:

So here's a couple of pics of my friends 1200 in his 78 Civic (same year as mine)..

StephT

And a couple of photos of my car, and yeah, that's a dirty big AC compressor on the other side, I told you it was fully accessorised! The wheels are genuine Watanabe with 1978 stamped on the back. They were made at the time for racing, and really hard to find outside of Japan (read impossible). I found them at an auction in Japan also, and won them for $100!!! But it cost me another $400 to get them back home.

apwhat

wow.. the level of thought and design you bring is awesome and inspiring.. whats next!!!

90efhatch

Nice work, I have always liked that body style.

StephT

Thanks guys, I should mention the photo of my friend's car has the old hood on it, I couldn't believe he fitted the earlier hood, but it turns out it was the only one readily available in glass, so that's why he had to make his own 78/79 style hood himself, which he's just finished, he also lengthened the vents in the hood to let out a bit more heat. I often hear people say the vents don't do anything, but letting out any heat can only help, even if it's only a little.

Another thing you might find interesting is the 2nd gen EN4 motor had velocity stacks fitted to both carbs. It's a really nice shape to, where they taper all the way down to where they enter the carb, and they give the intake an awesome throaty sound with the sports air filter, but only when you step on the throttle, as otherwise they're pretty quiet, and don't hiss like the stock downdraught carbs do at idle/low revs. Here are mine that I restored. I polished the velocity stacks and cleaned the carbs up with a product called AliBrite, and a LOT of scrubbing and rubbing etc. As I've already mentioned, I completely rebuild the carbs using 2 NOS GL1100 Goldwing OEM carb kits I found on eBay.

This is how they looked when I bought them. You can see the velocity stacks clearly in this shot. I removed the stone catcher screens and radiused the top edge removing the ridge that held the screens in place...







Here's another shot of the exhaust, and the CAD model...









Plus a set I made for a friend's race car that has larger primaries than mine (1-1/2") which I still think are too large for a 1200, but he wanted them, and I wanted the money! LOL! I didn't polish it like mine because at the time he said he was going to wrap them in heat tape, and I couldn't talk him out of it, but turns out he listened in the end! One great thing about CAD, I could design the race header to fit in the small amount of space that was available on my friend's car. The earlier 1st gens had a slightly shorter engine bay, but on the later ones they brought the grill out a couple of inches for a little more space. He was amazed at how close it was when he fitted it to the car, and all off of one set of measurements I took from under the hood of another friends 73 Civic.

PyroProblem

GREAT WORK!!!
Keep it up. Its nice to see this level of DIY. The time and attention to detail really shows.
Thats a cool little civic you got there too!

KNOW YOUR ROOTS

StephT

Hahaha! Thanks

I love your sig "Never gonna finish my build..." that's how I feel about mine, I have plans for soo many mods, and mods to replace mods! I told a friend the other day that for my final mod I'll probably return it to 100% original, and even fit the old 12" steelies... that's when I become an old fart of course! I never throw out any of the parts I upgrade for this reason alone, I just store them up in the roof space, in case I ever decide to go in that direction, you know, when 1st gen Civics become so old and rare that they start pulling a million$ at auction. I joking call it my retirement fund to anybody who'll listen! LOL!

GhostAccord

This is a very interesting build thread, love this gen Civic and individual throttles are sweet. I Always picture Hightower in Police Academy driving the 78 with no front seats. Your DIY ITBs and exhaust look nice in CAD. The exhaust looks great finished. In for the throttle finished product.

HYREV2NR

Man I am awestruck at his fabrication! OP you really need to post here more, I like what I see.

GagnarTheUnruly

iTrader: (3)

Beautiful work, very cool project. Looking forward to seeing this finished. It brings back nice memories of Dad's old yellow 73 Civic.

StephT

Thanks, I hope I can keep it entertaining, and I also hope to get advice, as I'm pretty much flying by the seat of my pants on this one, with no experience tuning ECUs etc, or with fuel injection in general. I did buy a few books, one written by the guys who own/run DIY Auto Tune which is also where I bought my MegaSquirt kit, plus bits and pieces, sensors etc. The other books are on advanced EFI tuning, which explain the fundamentals of what's involved, as well as the more advanced stuff. I also bought this cool add-on called the JimStim which plugs into the MegaSquirt ECU and simulates the engine so you can get a feel for how things operate. It has LEDs for each injector bank, ignition, tach, and a bunch of pots so you can adjust them to simulate variable outputs back to the ECU. That was the first thing I soldered together, and it was good practice to get my soldering skills back up to speed, as both it, and the MegaSquirt have some pretty fine soldering required, so I'd definitely recommend one of the pointy tips for soldering with (all decent soldering stations will allow you to swap them out).

I thought I'd jump back to the thermostat housing. The CBR thermostat housing is definitely the best choice for this project as it matches the 1200's needs perfectly, as well as the ITBs it was design to work with. On the 1200 intake manifold I have to squeeze two, 16mm coolant outlets from the head, which exit in between the inlet ports 1 & 2 and 3 & 4. Normally the manifold has is cast into it with a single outlet on the side of the manifold which also houses the thermostat, but for this application, two 16mm ID outlets squeezed between each pair if intake runners, with 2 lengths of heater-hose connected to them will do the job. I'll then attach both of those hose to two inlets I'll create on the back of the CBR T-stat housing. If you look at the picture below you can see an oval shaped opening on the back, where the housing bolts onto the CBR's head, but I plan on cutting a piece of aluminum the same size to close this opening off, and then fit two 16mm ID hose barbs to attach the two hoses I've been taking about, that come from the 1200's head. It'll look like this rough model I made for illustration purposes only...





You can also see on the base there's a good size outlet that the Civic's heater hose will connect to, which is in the same position it would be if it was on the standard 1200 manifold, where it sits below the thermostat, still receiving coolant flow before the T-stat opens as the engine heats up.





and finally there's the smaller outlet and inlet for the Honda fast idle WAX unit, which for those that don't know, has a type of wax inside that expands and contracts from the heat of the engine coolant that flows through. When cold it contracts and draws back the linkage attached to the idle bypass valves so the motor idles higher when cold, and as it heats it expands and the linkage is moved which in turn closes the air bypass valve. The idle speed adjusting screw operates on the same plate the wax unit is attached to. With the CBR ITB assembly there's a cable attached with a 'dial' on the end (see below) that you can turn to adjust the idle speed. I plan on making a small bracket to hold it on place, as obviously you don't want to leave it flopping all over the place.

You can see the two small fast idle inlet/outlets on the T-stat housing, along with a coolant temp (CLT) sensor. The difference with this coolant feed over the heater hose feed is it can't flow until the thermostat actually opens, which is obviously when the engine is ready to have the idle speed drop lower.





Below is a picture of another ITB assembly off a CBR600F4i (not mine). You can see the idle adjustment cable and the circular white nylon part that will likely fit into a slot cut in a 5mm aluminum bracket, or if I get the chance to see a whole bike at the wreckers, I'll grab the original bracket it slotted into (I'm betting it's just a piece of plated wire bent to shape so the adjuster spreads it open as it enters and then springs closed around it to hold it in place, at least that's how I'd design it). Either way, it's a minor detail.

hood ride eg

wow Great work dude and also Design

StephT

Thanks for that

StephT

Probably spent another 500 hours on this project since I last posted, and the ultimate full custom 1st gen Civic engine is approaching completion. Bored and stroked to 1375cc from it's original 1237cc and high comp pistons, original Honda RS cam that Mr Honda supposedly designed himself as his Road Sailing cam. It's a stage 3 cam in general terms. I'm having my standard cam hardwelded, then a Mugen MS-1 grind (stage 4) cam will replace the RS cam eventually, or not. I plan on driving it with the RS cam first, to see just how smooth is really is.

At the stage below, the engine parts are polished, ready to go down to chrome. All the aluminium parts have been polished, including the block which took about 300 hours by hand, using #150 to start off with, then moving through to #2000 grit, then I went to town on it with Autosol until my fingers literally ached whenever I moved them. They bounced back to life a few days later.

This is not going to be a trailer queen, but it won't be a daily driver either. Obviously, I'll be **** scared some **** is going to slam into me, but I have to show her off!

I have a fully machined, billet aluminium, adjustable cam gear I designed in SoldWorks (CAD), and a friend I know had a quantity of them manufactured in China (I believe?), and sent me one gratis for my time spent in CAD. It looks very similar to the one above, just without the inner button-head cap screws.

oh yeah, what do you think of my first alternator rebuild? :lol:

Robs_B18c

iTrader: (1)

Looks awesome, nice to see an update after such a long time.

1HGEJ2

iTrader: (1)

wow

StephT

far out! I lost track of how long I've been working on this!!! 3 years since my last post, and I've been working on it regularly!!!

for the record, I'm never selling it... never, I tell ya!

GhostAccord

Very impressive!

Can't wait to see it in the car and on the road!

Take your time, you do great work!

retodd1200

Looks really good. One of the prettiest 1200s I've ever seen. Those don't look like ITBs though ;-)

On another note, I really hope you don't believe the RS cam is a stage 3. If so you're going to be disappointed. It is a stock lift cam with 10 degrees more duration. Much improved torque over the stocker, but still small for the amount of induction you have. I used to autocross my 1200 a while back and I used Don Flores camshaft in my 1200. My best friend had the huge Mugen in his with DCOEs and my civic waxed his in the 1/8th mile. Maybe you can talk to your friend and get Don to grind you one of his cams.

I have also started pursuing the ITBs and was hoping you had got it working when I found this thread. Maybe you can update the progress there?

Todd

flamingdragon

Such a beautiful build!

Shreck1978

Steph

Some really nice posts going on, how is the convert the 1200 over to fuel injection?