Inliners International Forums General Discussion Engines Megasquirt a fresh engine - suggestions welcome

My Chevy 250 has just been completely overhauled, which includes a new camshaft. The car will not be out of the body shop for at least a couple of months.

Since the body is still under restoration, the engine will be ready to run well before the car is ready. I'm thinking of doing the initial cam break-in on an engine cradle such as http://www.eastwood.com/underhood-engine/engine-dollies.html . I'll use the original carb and distributor, so that I'm not trying to tune the Megasquirt at the same time as breaking in the cam.

Since the Chevy 6 oil pump is driven by the distributor shaft, and I plan to use EDIS with the MS, I plan to cut the top off of the original distributor and use the bottom portion to drive the pump. Naturally, I would face the shaft a bit shorter than the housing so there would be enough room to plug the hole.

Once the break-in is done on the engine cradle, I could then remove the distributor and do the machine work before the engine goes in the car. I'll be using an EDIS ignition system, so my plan is to get that working on the stand, using the Carburetor (one change at a time).

After I get the EDIS working, I could replace the carb with the Throttle Body and tune the idle and warm-up part of the MS injection. That way, when the engine goes into the car, all I should have to do is work on the final EFI tuning.

So, that's my plan. I welcome any suggestions.

That sounds good. What TBI are you using? Did you build your MS? You could probably get a start/idle/warm up tune from someone just to make it a bit easier. Have you done MS before? Please take lots of pictures and tell us step by step how you get it going. I started a MS project several years ago and ran out of intellect.

I understand running out of intellect. Megasquirt is not plug and play (except for the new ones designed to be). The tuning part is pretty easy to get close, but to do it right takes a lot more time, effort and understanding. I helped a friend who tried to build his own, but soldering some of the really tiny components got the best of him so he bought a completed one from DIY Autotune. I have one on a Lotus Europa, and it works really well. However, the one I'm putting on my Nova will be tuned for economy rather than power.

If you are after power, renting time on a dyno is the way to go. I don't know if that's true if you are tuning for economy. I just received MS files from another member, so I'll probably start with them.

I have not purchased the MS components yet, (over $3,000 for the engine blueprint dint in the budget). I've built a custom trigger wheel, and have the VR sensor. I'm in the process of putting all the tin on the engine. Once that's done, I'll figure out where to mount the sensor, and then remove the trigger wheel tooth (and rebalance).

I am taking lots of photos, and plan to post them on a domain I haven't registered yet. It should be a progress report on the entire vehicle build, including the engine work. I did one on a '65 lotus replica I built a couple of years ago. It's an inline 4. If you're interested it's http://www.nwseven.info

Nice build. The assembly of my Megasquirt was fun and went very well. My problems came with trying to use the Windows system needed to run the software and do the tuning. I got an old Compaq and did a lot of up grades for a good price. It is a dedicated computer just for car stuff but that is all on hold for a while. My MSII is already antique I think but it will still work..

The MSII is still just fine. Depending on how long ago you tried to tune it, there is new tuning software available. TunerStudioMS+ by Phil Tobin. I haven't downloaded it because I'm not ready for it yet. My buddy has it, and says it is far better than its predecessor.

Oh, thanks for the kind words on my build. It's a fun car for about 2 or 3 months out of the year. It rains in Oregon... a lot.

When I started my MSIII project I had 32-1 missing tooth wheel with a vr sensor on the crank and I used the distributor with a single tooth for the cam locater. Worked good.

Since you're using a cam locator, I assume you did a sequential injection system. What engine did you put that on? I have heard that sequential port injection doesn't work well with the Siamese intake ports of the Chevy sixes.

I had this on a 292 chevy with a turbo. I couldn't get it to run very well in the shop so I figured it must be due to the ports after hearing that from a lot of people. I later found out a lot of my problems were due to a homemade intake that wasn't sealing to the head. I had all ready yanked out the MSIII so I just put a 750 holley on it with the turbo for last season. I may go back to the injection next year. For sure if I can swing one of those new fangled heads.

Homemade intakes are a little tricky. I built one a number of years ago, but fixing leaks was a real issue. There are so many places to have leaks, porous welds, flanges at the head, flanges at the carb/throttle body, etc.

The new 12 port heads look awesome. Obviously, with a turbo 750 holley, you are after power and performance. My goal is maximum fuel economy. I think those new heads would be great for either. If opt for one, you may find yourself fabricating another intake manifold. I found a way to quickly isolate leaks at the welds. I have a friend who owns and operates an auto repair shop. He has a smoke machine he uses for isolating leaks of any kind. I used it on the last couple of headers I built. Just feed the smoke (under mild pressure) into one port, and plug all the other exits. If there is a pin-hole anywhere, the smoke will stream out. Easy to see. Then the only concern is getting true mating surfaces.

If you are going to use tbi, you might want to check out http://www.dynamicefi.com/ . He converts GM tbi ECU's into fully programmable units utilizing all oem parts.
No chip burning on the newest version, full data logging, boost friendly, autotune, and its around $600, or cheaper if you mod the ECU yourself.

Im going this way with my 350 turbo in my rv.

Wow. I just went to their web site, and it looks very interesting. I'll need to read a little more about it, but it may be a good alternative to Megasquirt. Thanks for the link and info.