Building the engine square costs just as much as my other kits and you wouldn't get huge MPG or huge power.

On top of that easy assembly without a full "kit" being necessary is out the window.

Using the 94mm Type 1 pistons increases every aspect of the assembly because the pin height demands .500 spacers on a stroker engine.

My recommendation of a 1911cc combination remains for the best all around results.

Ok, I'm listening... You got more parts that I should get for my 1911 ?

Sure, what do you have now??

I have:

no idea what cam is there. I will try and figure out what my valve train is this week.

Any tips on figuring it out w/out cracking the case?

The engine has zero miles on it.
So I know I need to buy some break in oil.

1.7 heads that have been fly cut for the 96mm setup
DRLA 36 carbs
throttle linkage on its way from CB performance
stock 2.0 exhaust, the engine is going in my 76 for the summer, then we're pulling it to put in the 73.

What I know I need:
Break in oil.


What I might need:
new jets for carb to match my unknown cam?

So, did you buy this engine or build it?? Partially build it?

Brad Penn IS THE engine oil that you need to buy... (available from LN Engineering)

Would there be any benifits to putting a 78mm stroke setup (crank, rods,pistons w/ the right pin height) on a stock 1.7?

Will the 9550 cam support a 78mm stroke 1.7?

here's the combo I am thinking of:

90mm pistons
78mm stroke
10:1 compresstion w/ flat top pistons
.040 D/H
stock 1.7 heads

piston dwell at tdc and bdc would effectively be longer, the smaller bore would give less dead space at piston crown to ringland, should be less likely to detonate, but small bore would shroud valves and restrict port flow.

trust jake, i'm shure he could come up with a combo that could push 40-45 mpg @ 120hp but would you pay $20k for all the coatings and one off stuff to make it happen?

Partial build, I'm trying to get ahold of the guy that built the bottom end and had all of the machine work done to it to find out exactly what is there.

I'm measuring the deck height and CCing the heads. What compression ratio should I am for? Or does this depend on the cam I have? which leads me back to finding out the cam.

(he moved to Texas, so it has proven to be *fun*)

This combo is close to the super 2L. The purpose of having the small bore and long stroke w/ small valves is to increase port velocity. with the right cam, it's possible to continue an intake air charge even AFTER the piston is on it's way back up. This creates great mixture properties.

NO, I would not/ could not(sam I am ), pay 20k for all the coatings to get 40-45MPG.

What if this combo could consistantly yield 32-35 with the possibility of 40!?

I have a two cyl. engine right now that is this excact combo

90mm bore
78mm stroke
8.2:1 comp.
3600rpm redline

it swings a 13" surface drive prop. and pushes a boat around through the mud and weeds. I lives it's life to to create huge amounts of low end torque @ low rpm's ( and does a good job of it).



If it had 2 more cyl's. (ala a T4) it would be a great motor

78 x 90mm is a great combo. The valves are only shrouded if the valves are to big for a mileage engine. Short strokes with large bores are great for racing and any high speed engine. Long strokes and small bores are great for low speed torque engines. They, by nature, require less induction. The smaller quench area of the bore means better thermal characteristics. Stay with a rod ratio around around 1.7 for even better mixture motion during quench. This combo is not nearly as easy to build as a 1911, and cost more, but would make a great DD. And if money is really no object, add a second set of spark plugs. On that tiny bore it would up the mileage even more. I believe 50MPG is realistic.

What does " the valves are shrouded " mean?

what does " keep the rod ratio around 1.7 mean?

how would this combo perform with the stock 1.7 heads and a 9550 cam?

Shrouded valves means that the valve is close enough to the cylinder wall that the cylinder wall actually obstructs the flow.

Rod ratio is the ratio of the stroke to the rod length... rod length/stroke=rod ratio.

I can't answer the last one :-)

The cam can dictate what compression you need, and your choice of cam can be influenced by what compression you want to run.

Sorry....

--DD

Thanks, Dave!

I got the builder's e-mail address, so hopefully I can get some answers as to what I've got for a cam so I can complete the build.

No doubt twin plug is our best bet for best performance and burn - that's what Jake's dyno day high MPG engine uses.
But for those of us that $$$ is an object with limits, where does multiple spark discharge like MSD and others come into the equation?? If one designs a TIV to run in the low rev multiple spark range, like 2.5-3K rpm, is it effectively like having twin plugs?? Or is the twin plug location(s) the big gain?
Would a 1911 with Ljet be tuneable for higher MPG vs. Djet vs. carbs??? Some SoCal folks claim 40 mpg on carbs, but common wisdom is EFI (even the old kind) is more fuel efficient.
Let's discuss
BTW - my stock 1.7 with 13lb flywheel and header kicks @$$ and gets 30 mpg on the highway

Keep this realistic!!!! Quit the day dreaming and hypothetical design!

Of course we can create 50 MPG- we have already done that! The Super 2 liter is a proven combo and is being further developed as we speak, but not a single person reading this can assemble that engine other than yours truly, because its a real bitch to build. Its also one of the most expensive engines I can create, for the HP output it IS the most expensive.

That said, the old 140K mile engine in my 912E has been my driver car this week as I broke it out of moth balls to get some MPG figures. Today it still gets 35 MPG after not having an oil change for 10K miles.

The 1911 is the combo. Cheap. Reliable and effective...
You guys just don't like it because you are stuck in the "Bigger is better" mentality, in that case I'll suck your wallet dry and won't get you much more MPG than the 1911 will at 1/3 the price. You'll swear the 1911 is a 2056-

Jake , as your engine runs cooler , what about removing fans to the blower ?
Thinking about alternator. Won't a 914 with a modern battery need less amps ?
Both should provide fuel economy ?

Battery voltage increase ignition system voltage. More charge energy= more power at the spark plugs, so you would not want to reduce that.
Street driven 914s need to retain their fan impeller blades...

Ok, so I got an email back. I've got a scat cam... no idea on the lift or duration, so I need to do some more research. AND... I'm starting to think I need to double check whether it was a 1.8 or a 1.7 to start out with. The car is a 73, has 73 FI.

Here I go needing to look at my heads again to find out what they are. All this time I thought they were 1.7 heads.

Differences between 1.7 heads and 1.8?

http://www.tunacan.net/t4/tour/heads.shtml

Thanks! that's a great website, much appreciated.

look at the top of any page here, there is a button way up top called 914info.

Look around in there...

Rich

OOPS. I really didn't mean to ask that. At the beginning of my post I said I had more research to do, and typed that out in question form instead of statement form that it was one of the things I was researching. Both Jake's site and Tunacan have been a great help in IDing parts.
Mr. HAM Inc posted to me in another thread that it didn't matter which 1.7 head I had, that I should just build with what I can afford, what I have if I can't afford something new (or something like that. really friendly and helpful advice, thank you sir)

So, thank you Jake, Tunacan man, and Mr Ham inc, Rich (for pointing out the link up top) It's making my research go much easier, as I have a tendency to research things several times when I get paranoid that my memory is failing from having certain health issues.

So, again, thank you for the help. I will make sure not to play jeapordy in my posts now.

If you want great MPG the engine is only part of it, get rid of as many pounds as you can, thin tires stock 165/15's, make sure bearings and brakes are in perfect order, leave the top on, windows up, no rabitt starts, no hard braking, keep it to 55mph, etc.

To me this sounds like in a 914 it would get pretty boring.....

That's why I thought about a Type 3 Squareback. Not much heavier than a 914. Much lighter than a Type 4 (411/412), and better looking too.

great read!
of course there is a tdi option as well, but my bet is 1911 would still be a the best option dollar wise

That' what i call digging out an old thread....