Type IV Engine design, going to built a motor, need advice about little details. Options

[mgphoto]

Hello,
Thanks for looking, I am in the process of deciding the direction to go with my original engine.
My limitations are the stock 2.0 D-Jet, bumping up from the 1.7, my engine is an EA case with 330K miles, it mics OK so I am intending to use it with the necessary 2.0L parts.

So if I am correct a set of 2.0L heads that will pump 180CFM of air is a good start. Coupled with a 9550 Raby cam should be a good match.

Since I am working with the stock D-Jet, displacement should be limited to 2056cc.

So a stock stroke of 71mm and the increased bore to 96mm is what I am looking at.

I see there is some customization of connection rod size and piston pin size, I have questions about what these changes will accomplish?

Advice accepted.
More questions to follow,
Thanks again,
Mike

[orange914]

Hello,
Thanks for looking, I am in the process of deciding the direction to go with my original engine.
My limitations are the stock 2.0 D-Jet, bumping up from the 1.7, my engine is an EA case with 330K miles, it mics OK so I am intending to use it with the necessary 2.0L parts.

So if I am correct a set of 2.0L heads that will pump 180CFM of air is a good start. Coupled with a 9550 Raby cam should be a good match.

Since I am working with the stock D-Jet, displacement should be limited to 2056cc.

So a stock stroke of 71mm and the increased bore to 96mm is what I am looking at.

I see there is some customization of connection rod size and piston pin size, I have questions about what these changes will accomplish?

Advice accepted.
More questions to follow,
Thanks again,
Mike

9550, 96mm piston, 71mm stroke, modified d-jet, electronic ign... you'll love it.

the 71mm rod has 24mm wrist pins slightly larger and heavier than the 66mm 1.7 pins.

[Chris Pincetich]

If you plan to order from TIV Store, try to get a hold of the old Jake Raby Aircooled Technology Podcasts. Lots of great info on what you want to do. Get comfortable, listen n learn (IMG:style_emoticons/default/beer3.gif)
You're on the right track, but be sure to get as much research done before calling Georgia as possible. I too have a '72 1.7 with lots of miles, but despite repeated attempts to kill it AX racin, it won't die! I think you'll need to machine the case to fit the 96mm jugs.

There have been lots of 2056 builds shared here online, but I can't recall if any retained the 1.7 heads. I've been told it is fine, it just limits high rpm flow while still providing plenty of off-the-line grunt.... (IMG:style_emoticons/default/confused24.gif) Keeping the 1.7 heads would save lots of $$$. I am interested in what others say about that.

Good luck (IMG:style_emoticons/default/beerchug.gif)

[r_towle]

All cases are the same.
No need to machine the case for the 94 or 96mm cylinders.

the head registers ARE a different diameter and will need to be machined if you are planning to use the 1.7 heads.

I would suggest you look into buying new 1.8 AMC castings and have a bit of work done to move the plugs to the 2.0 liter location and change the valve sizes to the larger 2.0 liter valves.

With new castings and all new valves etc, you should be good for another 320k of worry free driving.

Rich

[mgphoto]

Thanks for the info, keep it coming.
I have been thinking about the heads, my 1.7 are fine except for the exhaust studs and exhaust ports, I'm sure they can be repaired but I still have 1.7's.
I did look into the Hoffman and DRD heads, AMC castings reworked into 2.0 914 heads nice but pricey.
I am on the look out (just like everyone else) for a set of good used 2.0 914 heads but I am sure they will need as much work as my 1.7 heads, again making them kinda pricey.
Mike

[r_towle]

What are you trying to get out of the motor?
Just getting new 1.8 liter heads might be a good solid idea???

Rich

[mgphoto]

What are you trying to get out of the motor?
Just getting new 1.8 liter heads might be a good solid idea???

Rich

Hey Rich

I want to get close to 125HP with a stock D-Jet! Displacement increase to 2056cc max?
I want better gas mileage and cooler running temps! 2.0L combustion chambers and porting.
And I want it to be lighter and to last a long time! Lightened parts, flywheel, connecting rods and Nickie cylinders.

Simple goals or unreasonable?

My first choice was to go with new 1.8 heads but I see the potential of the type 4 and 2.0 heads are the way to go.

Thanks,
Mike

[VaccaRabite]

My 2056 uses 1.7 heads cut to accept 2.0 jugs. They work just fine, but 125 is too much power for djet. You will be able to get that with carbs or EFI, but probably not DJET. At least, not easily.

Zach

[r_towle]

Djet can do 125 hp....just build the right motor.