vinuneuro

Has anyone messed around with offset grinding the h22 crank for more stroke? I am planning/researching for an h22/h23 vtec build this upcoming summer and want explore all the options. I went over this great thread: https://honda-tech.com/zerothread?id=647731

It seems that the h22 crank is clearly superior to the one in the h23, so if it's feasible I'd like to stick with it. Also, if I go with offset grinding the h22 crank, would custom rods be a must? I can't imagine that being cheap, at all. TIA

v4lu3s

ANY offset grind requires custom rods.

2point6

Rewelding and then offset grinding to get added stroke can work, but a poor weld job can cost you an engine. Been there before and suggest a custom billet crank... but running a "properly" welded H22 crank currently.

mgags7

scott what do you mean by rewelding? is this to add to the journal before grinding it down?? why not just cut down into it?

is there any big strength difference with a smaller BE for the rod?

The_Head

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">ANY offset grind requires custom rods.</TD></TR></TABLE>

Could you just use rods with stock dimensions, but have custom pistons with the wristpin location moved?

mgags7

no, because firstly the length and/or wristpin location would have to be modified, and the crank side would be smaller than stock.....

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">scott what do you mean by rewelding? is this to add to the journal before grinding it down?? why not just cut down into it?

is there any big strength difference with a smaller BE for the rod?</TD></TR></TABLE>

Remember the H22 crank only has a stroke of 90.7mm.

How small of a BE do you want to have? How much stroke do you want to have?

Plan this first.

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The_Head &raquo;</TD></TR><TR><TD CLASS="quote">

Could you just use rods with stock dimensions, but have custom pistons with the wristpin location moved?</TD></TR></TABLE>

Yes, you can use stock rods. Custom pistons is a must.

vinuneuro

I don't understant how you could use stock rods. Wouldn't the rod journal be of different size?

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vinuneuro &raquo;</TD></TR><TR><TD CLASS="quote"> I don't understant how you could use stock rods. Wouldn't the rod journal be of different size?</TD></TR></TABLE>

If you offset grind (only), the crank jounal can only get smaller. Stock rods will not work in this case. So, depending on how small to grind the journal will depend on how much stroke increase you want... unless you reweld.

How much stroke do you want? How small of a BE do you want? You can only go so far. If you use a stock rod (mesurements) and reweld the crank then you only have to modify the crank and pistons as opposed to modifing the crank, rods (smaller BE), and pistons... Not a major issue, but it makes finding a rod choice to be a litfle easier.


Modified by 2point6 at 12:21 AM 12/25/2005

mgags7

so scott....do you think it is a better idea to get an f23 crank and grind it to fit b series rods, or to weld and offset grind an h22 crank....isnt the h22 crank forged?? is the f23 also?

v4lu3s

as far as i know ALL honda cranks are forged, but i would be interested if someone has better info than me.

vinuneuro

In the link to the thread I posted in the first post, the physical differences between the two cranks were discussed.

The_Head

If I could do it all over again, I would of stuck with the H22 crank instead of the F23 crank.

vinuneuro

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The_Head &raquo;</TD></TR><TR><TD CLASS="quote">If I could do it all over again, I would of stuck with the H22 crank instead of the F23 crank.</TD></TR></TABLE>

Please explain. Would you have gone with a modified h22 crank route?

mgags7

yeah head...would you have ground the h22 crank down?? what reason do you have for not liking the f23 crank??

The_Head

Yes, I would have gone with an offset grind on the H22A crank to 93.7 mm, used some longer off the shelf B series rods, and custom pistons.

https://honda-tech.com/zerothread?id=1200515


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Innovation &raquo;</TD></TR><TR><TD CLASS="quote">Well, to start the counterweights are about as bad as it gets... They are shorter than the outstretch of the journals which isnt a good thing at all for a motor with intentions of performance. Theres nothing you can do about that though, theres no way to add mass to the counterweights.

Second, the journals are far too narrow and dont provide a adequite oil cushioning surface. One of the first things any of the pro guys do with the K series cranks (same rod journal width as the F23) is have the rod journals opened up to house a .935 width rod and enable the use of H22 bearings. Thats a must if you want that motor to last at anything over 7000 for any amount of time. K series motors spin rod bearings like crazy, as do F23's. That needs to be addressed or you'll pay for it later.

The counterweight in itself should be enough reason to not want to use that crank. It was never intended for that can if use. Thats evident in its design. There isn't a single engine builder that is worth a dime out there that would let you or advise you to use a stock F23 crank... It needs to be reworked or youll be spinning bearings like crazy... Revving to only 7200 is basicly going to make the motor useless, youll need at least 7800-8000 with any good cam...

Im telling you man, your building a time bomb, take my advise on this one </TD></TR></TABLE>


Now that's just one opinion. My engine builder (and friend) says my block will be able to do 8000-8500 with no problems. If it does that, fine. But am I going to take it that high all the time? Hell no. Only when it's absolutely neccesary.

mgags7

well how about grinding an h23/f22 crank....the 93.7 isnt too impressive when you could have just taken an f22 crank of the shelf and been done with it....

The_Head

I am just more moderate when it comes to choosing components for a setup. I got conned into using the F23 crank before I knew anything about it.

87 X 93.7 = 2228 cc's (H22 offset ground 3 mm)
87 X 98 = 2330 cc's (H23 offset ground 3 mm)

89 X 97 = 2414 cc's (my G23VTEC motor)

People have had problems with the H23 cranks too. Some haven't. So, is the extra 102 cc's worth the possible problems you "might" have when revving it past 7000 rpms? It's up to you... I guess it depends on how you drive our car.

vinuneuro

Even with the H23/F22 crank, it seems that the minimum that needs to be done is that it needs to be dynamically balanced to rev high enough to be worth it. Ludeykrus showed in the pictures that the H23 crank was only drill balanced, where as the H22 was cut as well. Then theres the issue with the counter-weights with H23 and the F23; they can't be made larger.

Seems as though, the modified H22 crank is the better option for stroke as well, all though it'l be more expensive because of the necessity of custom rod and/or pistons. This might end up being the correct way of doing it, in which case, I might wait till im done with college.

The_Head

If you're going to offset grind, youre going to need custom something... pistons or rods, or maybe even both.

I'm taking the following precautions to keep my setup from blowing up at high RPM's

1. Rotating Assembly is fully balanced
2. Crower connecting rods
3. Pistons are custom and about 50-75 grams lighter than stock F23 pistons
3. Fluidyne crank pulley to quell torsional vibrations
4. Running 20W-50 oil for a better oiling cushion for the skinny rods

PocketRockets Racing

just offset grind down to the 1.770" B series rod journal size.
you can take the oppurtunity to place a large radius of the journals at the same time.
I would not suggest welding at all.
makes more HP.....you can a lil torque, but still revs high.
the h22 crank is real stout.
HP is made in the HEAD, h22 heads can flow up to 340+ cfm, when done properly.
if you ever hear an h22 at 9500-10,000 rpm......it should decide then end there to use the h22 crank over the 1st gen h23 crank
now, this is a fully prepped H22 crank:

vinuneuro

How much do you charge for services pictured here? What all is exaclty done with this crank?

Also, what do you mean by 1st gen H23 crank?

The_Head

1st gen = H23A1

2nd gen = JDM H23VTEC (came in accord wagons) perhaps?

PocketRockets Racing

yes.....1999-2001 h23a ,for 95-98 mm strokes, its the crank to use. .......besides a billet crank