D.O.A sells de-stroked engines.

D.O.A. Racing Engines

I have heard of people de-stroking turbo motors. I wouldn't mess with it otherwise.

 

read this on civic forum

When you destroke an engine using the method of replacing the crank shaft, you are shortening your stroke. Stroke is the distance a piston travels from top dead center to bottom dead center (TDC and BDC). The bore is the distance from edge to edge, also known as diameter, of the piston head. The crankshaft spins in a circle, as do the rod connecting points on the crank shaft. These connecting points will make a diameter (when spinning) equal to that of the stroke. So, getting a smaller crank, makes a smaller diameter, and makes the pistons move up and down over less ground, thus de-stroking or shortening the stroke of the engine. This, in turn, will change the displacement of the car's engine.

A stock D17 has a 94.4mm stroke, and 75mm bore. The formula for calculating displacement is: N * stroke(mm) * bore(mm) * bore(mm) * .0007854 = displacement in CC's. (N is number of cylinders)

So for a stock D17: 4 * 94.4 * 75 * 75 * .007854 = 1668.1896 or 1668CC's.

When you destroke the D17 to a 1.6 liter engine, you are changing the crank, and making the stroke shorter. The connecting points on a 1.6 liter crank make a diameter circle when spun, of 90mm. So they also move the pistons 90mm from TDC to BDC.

So for a 1.6liter crank: 4 * 90 * 75 * 75 * .0007854 = 1590.435 or 1590CC's.

Now, here's where you come into a problem.....

When you change the crank, you are lowering the height at which the pistons sit in the combustion chamber. (the pistons are lowered approximately 2.2mm, or half the change in diameter from one crank to the other) What this does is lower the compression your car is running quite substantially. There are 3 things you can do to solve this.

A. you can buy longer rods, which will restore the pistons to correct height. (you'd need rods that are 2.2mm longer than stock)

B. You can buy taller pistons from rod connecting point to top edge of the piston. (again, must be 2.2mm taller than stock)

C. You can shorten the deck by 2.2mm, thus reducing the extra volume gained in the combustion chamber.

There is de-stroking of an engine in a nutshell.

 

I was thinking a turbo'd destroked 22R/E would make use of the turbo better.

 

Do they sell shorter rods. If they do id probably buy higher comp pistons and maybe mill the head a little bit and use bigger pistons?? But I can't find anybody that sells shorter rods??

 

OK so you change the rod stroke ratio to Honda motorcycle levels.
What next?
you run into the issue of breathing at those higher speeds.
The 22R even the 20R doesn't flow very well with 8V.

For the amount of work and resources (custom rods and pistons and elaborate Blueprinting) I don't think it's worth it.
It would be cheaper to swap to 4AGE if I wanted to rev.

My truck is what my Honda isn't.

 

My truck does not stop pulling at 7 thousand RPM. Its just I know the thing will detonate at anything more.So I let out of it.

You dont need to spin much more than that. Trust me.

The sound is indescribable....

 

If I do destroke it, it will definitely involve polishing the intake mani, porting, and headers so I think air flow wont be a problem the only problem right now is finding a good way to destroke it??

 

And larger valves and pistons

 

Not worth the time IMO

 

You know the rules. This requires a video.




I will honestly think that de-stroking the 22RE will make you lose your torque and push it up the RPM range, which is not good.

 

yup i know itll lose some lowend but its gonna raise the rpm limits its not probably the best thing to do but i want something different, and wanna do something nobodys done to a 22re before.

 

http://www.toyotaminis.com/forum/104422-post8.html
http://www.toyotaminis.com/forum/104423-post9.html

These will help the most.

 

Just came across this, a bit late. So, I've discussed this at length with a few people.

Destroke a 22RE? Turbo? N/A? Our talks were of a means of developing 200hp the "easy" way.

My engine combo was a 78mm stroke 95mm bore, N/A.

Head was decided on the 20R, big valves and good port work. Intake side of the head welded to match the 22RE lower mani. The 22RE lower manifold filled with aluminum epoxy and CNC ported to match head.

Cam would be in the 235 to 240 degree @ .050 lift range.

Block would be machined to accept chromolly sleeves that would allow a 95mm bore. Pistons designed to place the pins in a position to lengthen the con rod to create a 1.8 to 1 rod/stroke ratio.

In a nutshell, the numbers produced a tad over 200hp and tq with peak tq around 4500rpm and peak hp at close to 7200rpm. Not really a 'street' tune.

That engine build would be in the neighborhood of 10k to build and tune. Definately not worth it.

 

Doa's big bore 22r hybrid will get you in the 200hp ballpark for 4k. Not much point in destroking unless you are racing at high revs all the time.

 

I would just find forged internals and have good head work. MLS gasket with arp fasteners, lightweight valve train(Ti) and a decent ecu to manage fuel/timing/spark. I believe not all engines have a positive reaction to destroking.

 

The biggest thing you are fighting with chasing revs is piston speed. The recommended max speed is 3500fpm. To find piston speed it's stroke×2×rpm÷12.

 

Yep, I hear all y'all. Whole thing was about what could be done.
My current 22R project is a 94 stroke 93 bore grunter to just putt around in. That's just on the table for now as I'm supposed to have surgery on my shoulder/s.

 

You might consider an 18rg the are the twin cam version with a bore stroke 89mm x80mm. The block would be a straight bolt in but you would have to change the exhaust coolant lines throttle cables etc. A good 18rg will output around 140hp stock which is more than a stock 22r turbo.
They are however getting quite rare, but you might get lucky

 

Only problem with the 18RG is locating the parts.