So a local guy here tried angle boring a V8 a while back. Hit the ater jackets. Had a new block made and picked up around 70whp and 43tq. He was beating everyone in his class until the engine was outlawed. Now I think just about everyone knows about it, and I've heard Rousch might be using it in their Nascar program (brad?). Anywho, could there be any benefit in using this in a i4 Honda engine? I haven't taken the time to figure out how much thrust there is in either a Honda or a V8 so just looking for off the head opinions.

 

Do you mean offset boring like the VR6?

 

No. I mean actually changing the angle of the bore.

The more I think about it, the less I think it would help. But I'd like to hear others opinions.

 

Oh ok...I see how that could have an effect(exactly what I don't know) on a v-style engine but I don't know why you would want to do it on an I-4.

 

Neither do I. Thats why I'm asking. This is more for the bigger stroke guys.

 

Could you draw me a picture? Sounds interesting.

 

Sounds like it changes the fulcrum point of the piston, making it push "harder"on the crank. The rod is more perpendicular to the crank when it starts the power stroke if you center the bore over the "downward" side of the crank throw. I can see someone finding HP.

 

I am not familiar with angle boring, although I know some of the v8 guys angle mill their heads--its really only effective when using a wedge or even a semi-hemi style (peanut shell) CC like all the top pushrod v8s use nowadays. I believe angle milling on a wedge chamber can help to unshroud the valve as it opens--pushes it farther away from the cylinder wall.

 

Here is a definition for those wondering, it is NOT angle milling!!

http://www.freepatentsonline.com/20030015165.html

 

I.E. you get a better angle between the rotation of the crank and the downward motion of the conrod on the power stroke. Yes? And what this angle milling is i think is "eyebrowing" the block to unshroud the valves. I've got two different pictures in my head with this conversation. One concerns the bore on the block being angled slightly, and the other is eyebrowing. Tell me if i'm following this correctly.

 

Hmmm..Interesting... I could see a possible advantage in "angle boring".
Maybe reduce a little friction during the power stroke? But then you might gain a little friction on the upstrokes?
This would be an expensive experiment assuming you could only do it on a sleeved block (more meat, more angle)?

 

Side thrust on the piston skirt would be an issue for sure. I think there might be a magic angle that works and has some sort of longevity. I think that would be a potential for drag cars which would get torn down on a regular basis, but as far as a street or endurance engine, it wouldn't last as long as a conventional engine. Instead of angle boring, why not lower the main crank journals?

 

so essentially you are just changing the crank/rod angle for peak cylinder pressure allowing for a more efficient thrust of power......? yes? no?

i'd like to see how this would be done tho because i dont see it happening in a factory block without major modifications to compensate for the different cylinder angle.

 

I believe thats the idea. It took me a while to grasp it.

 

say someone did do this on a honda engine how would you relocate the head to match back up with the bores? you could leave the top of the bore at the same location and start the angle at the top of the bore.... but then your bore wouldnt be in line with the crank. if you start the the angle at the bottom of the bore to be in line with the crank then you have to relocate the head to match the bores. it all sounds pretty pointless and not worth the money it would take to fix everything you messed up trying to get an angled bore......

 

Angle mill the top of the block so it stays perpindicular with the bore. Rework the combustion chambers.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">Angle mill the top of the block so it stays perpindicular with the bore. Rework the combustion chambers.</TD></TR></TABLE>

then you would have to mill the head at the opposite angle to get it to sit back flat on the block cause the head studs are in the block & head straight.

 

I think you could just drill the head stud holes in the head. A couple degrees change of bore wouldn't move things that much.

 

The Honda Insight crankshaft is offset 14mm.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by http://www.insightcentral.net/encycl.../enoffset.html &raquo;</TD></TR><TR><TD CLASS="quote">The engine block has a unique, offset cylinder design in which the bore center is offset 14mm from the crank center. Maximum combustion pressure occurs at a point where the connecting rod is straight up and down in the cylinder. In this position there is zero lateral force so friction and piston slap are reduced.

As a result of the offset construction, the combustion pressure is used more efficiently since the rod is near it maximum leverage point with the crankshaft.

</TD></TR></TABLE>

Same theory, different execution.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by njn63 &raquo;</TD></TR><TR><TD CLASS="quote">The Honda Insight crankshaft is offset 14mm.

Same theory, different execution.</TD></TR></TABLE>


it would take more than a couple of degrees to accomplish something like that

 

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


it would take more than a couple of degrees to accomplish something like that</TD></TR></TABLE>

If someone is going to go through all the work to mill the head, bore the block, find a solution to the head bolts not being lined up, etc. etc. i'd hope they're going to do it more than a couple degrees.

Honestly though, I think moving the crank would be easier than angle boring as far as modifying an existing block.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by njn63 &raquo;</TD></TR><TR><TD CLASS="quote">


Honestly though, I think moving the crank would be easier than angle boring as far as modifying an existing block.</TD></TR></TABLE>
agreed, but neither would be an easy task

 

I have seen people offset the wrist pin to get a similar effect.Many oem pistons offset the pin to quiet piston noise but the performance way is to offset it in the other direction.Nextel cup engines are built within a very tight set of rules an they do some very strange things.One of the things that they have been doing for a few years is hot honing the blocks.They are final sized with special deck plates and 200 plus degree fluid is pressure fed through the water jacket.The practical issue is the engine needs to be near operating temperature before it can be started.Many of the things they do is worth 5 or six hp.On a Honda na engine your looking at one or two hp.The hot hone system a few years ago started at $25k and that didn't include the honing machine.

 

I can think of a way or two to make my own hot system on the cheap, assuming a pre-existing machine could be used.

 

Good thread