Hi to all, here's a few pics of some of my engine's private parts. The new parts save over half a kilo per rod and piston. Plus I would also anticipate more saving from when the crankshaft is cut down for the journals and balanced for the lighter componants.









The rather eerie thing is somebody has etched the numbers 928 into the side of the rod cap, how is that?

 

More info on the GT motor and "Short" motor. You could email it if you prefer (dfwx@hotmail.com)

 

Damn, that is a short skirt. Do you expect more blow-by?

Mmmmmm, short skirts.....

 

Well the pistons are made from 4032 low expansion alloy, so the piston to wall clearance will be tight. As we know the block material is very stiff and as such wont trumpet, I think if it trumpets it breaks. I have total seal rings which I'm told are very good. I also have a 4 stage dry sump pump creating vacuum and hopefully pulling the rings onto the walls. So no I would hope not.

Cheers Greg

 

I had those in my engine. They caused problems with the alusil and scuffed the cylinder.

 

With those light components that will be one revvy motor, cool.

Chris

 

With the wrist pin is a different spot will you need to machine the block to clear the rod?

 

If you mean numbers on 928 rod you got lucky it says 928. There's 1/1000 chance of it. When 928 rods are made, large end bearing surfaces are machined when rod is bolted together. This creates very accurate and round big end but at same time means rods and caps can't be mixed as there could be small differencees where hole was machined compared to bolts position. To make sure parts stay together they are numbered consecutive from 1 to 999 and then sequence starts all over again. Chances of one workshop having two rods with same number under work at same time is quite small and thus rod and cap should always stay as pair. It's also important to put engine together so that numbers on rod and cap are on same side in 944 engines for example. As on 928 rod caps are not reversable (IIRR) this doesn't matter when it's obvious which way to put them back together.

 

What size honda rod is that?

 

Hah. Hey Sterling my old friend. The 78 motor is together, and the 89 block has all its pieces sans 87 rods to go back together at a " +Stock " level.

I'm just keeping tabs for when I put the GTS crank I have into a bored motor. That will be the monster.

 

nice pics greg!! so how many HP are the honda rods good for??? just keeping tabs for when my old gal blows up on the dyno....

 

Hi Jim these are not the Total Seal one piece rings, they are just custom but standard looking rings (normal ring end gap) made be Total seal. Rings sizes are 1.5mm 1.5 mm and 3 mm.



As to skirt loadings, my rod to stroke ratio is about 1.85 to 1, so that is just considered a long stroke motor, 1.8 is considered the changeover point. I don't see any reason to machine the block as the crank's outer dimensions wont change. Rememer that the stock crank gets stroked out to about 86 mm, which means with these rods all 928 cranks can out stroke a GTS.

As to the 928 no, it is on all of the rods and it was put on buy hand, yes Errka I am familiar to what you are saying though.

These rods as far a power capabilty goes, are the bees knees, they would happily hold these pistons at 9500 rpm and 800 hp +. These are Nascar componants. Honda rods are actually stronger than the standard size rods by the fact that they are smaller. Less weight, but the bigend (circle) that holds the pins is stiffer because it is smaller, it is the crank if anything that would be weaker. (The other nascar componants are the valves, Ferea 7mm and the tappets have been micropolished by a Nascar guy, then to be DLC coated)

My engine will only rev to 7500 rpm so the mass forces will be less than that of the standard engine at 6500 rpm. Likewise the bearing speed will also be less and as such the frictional losses will be less. Honda rods are said to save 7 hp at 7000 rpm versus standard rods. This doesn't take into consideration that longer life due to less stresses and the revability of the engine due to lighter weights.

I would like to see somebody turning down 928 cranks and making these mini stroker kits, this is the reason I am publishing all the info to do this job. I think in all, 10 kgs could be saved from these engines which makes them pretty light when compared to the 4 valvers. Factory weight for the 2 valver is about 245 kgs and the 4 valvers are from 264 to 266 kgs if I am correct, so it could be 235 kgs, a saving of 30 kgs, that is quite a saving, I certainly wouldn't like it 30 kgs dropped on my toe.

 

Can you tell us more about the Total seal rings (as you suggest - normal gapped rings, but custom)?

Also, are the Honda rods off the sheft pieces - i.e, could this be re-created with basic directions? I forgot if you ground a stock S4 crank or something else.

 

Hi Brendan, as to the custom bit, there isn't a off the shelf chrome ring made for 4.060" in 1.5 mm. So I had Total Seal make some up. Standard type ring but 1.5mm in chrome.

The Honda rods are off the shelf but can be expensive new, in the top brands like Carrillo and Lentz from about $1500 to $2500. These normally come with the reusable Carr bolts, which are a $400 upgrade over standard bolts. Somebody asked me some details about the rods and the big end diameter is 1.888" however I know Honda would never use such a size more like 48 mm. But as I suspect the guys in the U.S. have just decided to use something very close and call them Honda.

I don't know if scat or eagle make cheaper rods, I bought mine on Ebay, got lucky as mine are perfect but I have seen a few rough sets I wouldn't touch.

Cheers Greg

 

Since I have been on the rennlist, I have not seen anyonetry building a stroker by this method.
Great idea. Have you gotten quotes by machine shops to turn down the crank so it will accept the honda rods? Any quantity discounts? See any problems with oil journals after turning down the crank?
The design for the pistons is radically different too. Were they modeled after the honda as well or some other design?
What is the proposed CR ratio on this unit, for potential boostards who may consider boost and a stroker?
Sorry for all the questions, but this is very intruiging.