Modify the MCI?? YES!

[tonyton]

We are trying some more tricks on this MCI engine and thought some may be interested. Since I had honed the cylinders and reused the old rings, I ordered a new set to get it right. I had a set of old style, standard pistoms and the new rings installed. The OLD pistons fit to the top of the deck perfectly. So you can order old style pistons and rings for your MCI and use a modified head.
If you are not replacing the head or milling your existing MCI head, don't do this, you will lose some compression that was engineered in the stock engines for a reason.

[tonyton]

The other thing I may try out are different ignition timing settings. The MCI flywheel could easily be changed for another few degrees advance or whatever. The bump that holds the flywheel in place can be removed and replaced. Heres a picture. If you turn the fly wheel clockwise you get more advance. counter would retard.
Too much advance would make it harder to start. MSD makes a retard switch, that would allow to fire at stock BTDC to start it up and advance it up to 15 degrees for flying. I may try that, since I use MSD, it wouldn't be too much more $. My brother ordered his video camera.
BTW, I will have a competition 295 head soon and maybe, some custom ground cams.
I want to see what a real cam will do and Fast Fred is on it. This is experimental at this time and is actually being measured and figured. Cyphering, I think they call it. Thanks for looking

[sabercat]

thanks for posting! looking forward to the results

[Subarumouse]

Hello Tonyton & Co

My 350 is back and here are the results of the used cam in my engine.
I measured it 3 times to be sure!!
This, because its very different from yours!

The smallest is 20.6 mm / 0.809 inch
The biggest is 25.2 mm / 0.986 inch

So the valves are max 4.6 mm / 0.181125 inch open.

And you are right, the belttensioner is at the max, so max shaved off.

Benno

[Subarumouse]

@Tonyton,

As far as i can see it, the heads are also different at the two oil return openings.
At the "strange" head they are bigger, so for higher revs?.

For my own 350 head; now i get the reason why the compression of my engine is still lower as a 350 with a 295 head.
In mine they searched the best combustionchamber in combination with the grinded / tuned cam.

The valves in my 350 head stay open longer.
Maybe they are also higher in the head on the seats.
That could be the reason that they aren't touching the piston.
(As if the valveseats are worn out)

O, the bill for fixing the broken rod was all in (2 rodbearings, grinding the cranck, new oilkeepers round the cranckbearings, cleaning out the engine and building it together) € 315,-- / about $ 400,--

Benno

[tonyton]

Sorry for the long delay. There has been a lot of testing, more rsearch on the cams and think I have more info that some of you might like to hear.
First thing, on the MCI engine, when I tightened the rods, the pistons did come up to the normal height. That was about .020-.030 above the deck, so don't put a flat head on it , unless the pistons have been shaved down to the deck.
Second, The timing advance is very touchy and didn't prove effective. It cut the low end power and was limited to a powerband of 3500-5500 rpm. I tried it in different estimated degrees and it would also get hot fast! A mechanical advance may work, but the stock position proves best for overall performance.
We (Fred) is having couple cams welded up and ground for a higher rpm and to match a new head. It is the postion of the lobes on the cam, not just the height and shape of the lobes...the degrees before and after tdc that they open and close. Unfortunately those had some problems with warping and we are trying again. Cast steel doesn't like to flex.
I have some results from early tests and will post them soon. We ran a stock 36v, a stock workhorse, a modified workhorse with combinations of cams over three test areas. The modified is obviouslty faster, but the stock workhorse was beat by the 36V. One of the tests is an 80 yard uphill. It's interesting.
Hi Benno, It is the combination of your compression, porting and cam that give you the rpm that you acheive. I'm almost convinced a custom cam and high flow head woukd give you the rpm. In my case, the cart is heavy and the high rpm will be harder to achieve, if possible.
Your builder has done a good job and that is not a bad price, here. I appreciate your input, as always.
Thanks for reading....