Even at an over-bored 468, you'll be surprised how much steel is still "in the way" of airflow. As stated above, my motor is 468 and we did bore notch it.

Can anyone post a picture of what the block looks like when properly bore notched? How much material is taken out with this process? Is the material that is removed enough to cause a lose of compression by enlarging the cc's of the combustion chamber?

I have heard of this process but never actually seen it done before. This thread has started my interest in this again.

Well, here is the first of 16. Only 15 to go. Is the quality ok? Any further suggestions? Hope the answer to Checkmates compression question is negatory. As you can see I have flat tops and running what are now 115cc heads. Don't want to loose any compression.

Thanks for the help,

BT

That's what I wanted to see!! Good picture. Those reliefs don't appear to big, maybe not even enough to effect compression.

BT;

Can you measure the cc's of the cylinder before and after your relief work? That will tell you the real story on compression.

I don't have a method to cc Checkmate. I am sure this is an unmeasureable change in compression. Particularly because ther was a step notch already there from the factory. The one I have done was quite easy, but I will say somewhat nerve wracking. Hopefully as I go along I will become more skilled.

If you want to see a skilled notch job, go up a couple posts to where talk was about JimVs work and where to view it. Those are some sweeeeet notches.

Another first today was that picture. Never posted a pic before. Bought the wife (ie me ) a digital camera for christmas. I'm gonna like that!

BT

Another notched pic.

Hey KAAMA, it's not that I do not want to, but I already have 4.500 bores and you seemed to think that little will be gained by notching. Is that right?? No need to spend the time or $$ if the reward will be unoticeable. Thanks, A4

Allan4, yes that is correct. The larger the bore size the less you will benefit from a bore notch job. Although I DID ask JimV to bore notch my blocks with the 4.500" bore size, but he only did just a little. He did it because I was running a 2.300" intake valve when a 2.250" intake valve is usually used on a 4.500" bore size. Next fall I will have my blocks bored out from 4.500" to 4.600" which will really unshroud the big 2.300" valves I now have.

The Merc HP450 engine which is a 454 cubic inch engine would really benefit from a bore notch as well because I think Merc used a 2.250" size intake valve in that particular engine which is kinda BIG to begin with. Bore notching would help unshroud the intake valve well.

Blue Thunder, Boy!.....I...I say boy! Ya doin' that ----I say ya doing that all wrong now son, ya heya?

Just kindin--- that bore notch is looking pretty good on your first cylinder there son. Remember, you can go out to within about 1/16th of an inch or so of the gasket you are using. If you look at JimV's example as he has pictured, it shows that he followed the gasket pattern closely and removed as much metal as he could for optimum air flow. N0 beer, coffee or cafein----All you need to do is good/accurate prep work and keep a steady hand and you'll make it home! As long as you are using the same model (part #) of head gasket and do not exceed its bounderies you'll be fine. Same goes for the TDC of each piston with the top ring within the cylinder bore---if you go too deep past that top ring and EEEE BOMBRA SEEE.......boy, you gonna find yourself in THE LAND OF NO RETURN SON!-----GULP!

Tinkerboater knows his bore notching. He is also one of the fussiest people I know. He has done this to assembled shortblocks (his own) so he would be able to give you good info on best way to keep things clean. I will send him a PM to let him know about this thread.

Not sure on this but it seems like used head gasket is prefered.

Wow Kaama, you scared the chit outa me... but I must say, I do deserve it! And thanks backformore for posting that ferrari pic next to my hugo pic.

I am using an old gasket and it is helping a lot. I only spent about 10 minutes on that notch, so I will clean it up to look more like the ferrari notch tonight.

No beer eh? HMMM, dam.

BT