cutlassefi

Many of you have heard me say many times that I use a BHJ Bor-Tru plate to bore with then a BHJ Torque plate to hone with.

Here are some pix on the DX build I'm doing. Hopefully this will help everyone visualize what's being done and why.

First the block is align honed, then it is squared decked where both decks are even, parallel to each other and at the correct angle vs the crank.
Then and only then the plate is installed and the boring bar locates off the holes in the plate, not the block nor does it use the dowels as a reference, it uses no. 1 journal as well as the squared deck and the mains so that the bores are perpendicular to the crank and over center.

Hope this helps.

P.S. this block had one whole bank of cylinders that were almost .040 off center towards the intake side, not to mention at an incorrect angle as well.

cutlassefi

Another pic.

Yellowstatue

Is that ballpein hammer for minor adjustments?

VORTECPRO

To clean up a .040 shift how much did you have to bore it clean up the cylinder, and how did it sonic ck after the cylinder was bored?

Rickman48

You'd have to go .060 over with .005 cuts to even the pressure on the cutter by the time you got to the last .020, if it was allowed sonically.

joe_padavano

So the difference between boring plates and honing plates is that the boring plates provide registration for the bores as opposed to following the existing bores? I'm surprised the boring plates don't pick up all the head bolt holes.

VORTECPRO

Joe, that plate you see there is only to locate the bores, the boring bar sets up off the bore in the Bore Tru plate, the bore tru plate locates off the head dowell pins, the bolts are only used to hold the plate in place.

VORTECPRO

Got a question, how do you know the dowell pins are in the right place?

cutlassefi

Well mister engine builder because you don't use the dowel pins in the block to locate the plate, but you knew that right?

That's always been my criticism of BTR. His CNC program locates off the the dowels, very seldom are they in the right place.
There are dowels in the vertical supports that hold the plate in place. The bolts you see are just to secure the whole fixture. If it's not right fore and aft that's not an issue, the wrist pin/piston can be moved a little front to back without any adverse effects.
However by align honing it first then square decking it you assure that the plate is at the right angle (45 degrees between banks) and that the cylinders will be located correctly vs the crank, perpendicular and at the correct angle. Again front to back is not an issue.

This block had an almost .040 offset towards the intake side but only on one bank. It would take an overbore of .080 to completely clean that (.040 off each side). But it cleaned at just under that, however we had already ordered +.030 pistons (4.155) so no issues.

Rickman- not sure why you would have to cut only .005 at a time, you must have a very inaccurate/unstable boring bore. I have personally bored hundreds of blocks, you can cut .020 or so at a clip with no issues at any time, even with an offset. What happens when you have to bore a block for sleeving because of a crack or blown out cylinder wall? It doesn't hit all the way around on that either. I assure you they aren't taking cuts of .005 at a time. It's a little harder on the tool when you do more but it's still done all the time.

I've done std 455's that had to go to .040 because 1, 2, or 3 cylinders weren't in the right place.
The tooling of years ago wasn't that great.

Hope this helps.

VORTECPRO

My program locates off the thrust.

11971four4two

Mark votecpo please show us your set up for boring blocks of Olds
Thank You

http://www.yellowbullet.com/forum/sh...d.php?t=244725

380 Racer

He probably borrows SBO's........

cutlassefi

Hmmmm, ok. But you'll need to explain how that corrects the angle(s) of the bore as well as the side to side positioning. It seems to me that locating off the thrust would only really influence the front to back position of the cylinders, which happens to be the least critical of all.
Got pix and an explanation?

And anybody want to guess why the dial indicator is positioned to read off the deck? Bruce why dont you take a stab at it.

VORTECPRO

Your machinist is checking the run out between the bore tru plate compared to the cylinder below the bore tru plate. Which you said was .040, but cleaned at less than .080. How your machining your blocks is old school, please dont try try and imply this is state of the art machining, theres nothing wrong with it in my eyes, but CNC is far more accurate than the old BHJ bore tru method. And one more thing worth mentioning is, your machine shop was willing to buy the tooling from BHJ to machine DX or 350 olds blocks, that says a lot about them, dam good shop. I dont agree with them back cutting Exhaust valves though.

cutlassefi

I'll ask one more time, how does locating off the thrust guarantee the accuracy of the bore positioning, side to side and at the correct angle?
This is your last chance, then I won't ask anymore. I'll just assume at that point that your "state of the art" CNC program isn't as good as the my "old school" Bor-Tru.

And please quit sending me BBC dyno sheets. As I've told you a hundered times already I'm not interested. Save them for someone else.

Thank you.

VORTECPRO

Mark, you love the dynosheets! Along with the build pictures, LOL I have to get to work right now, butt we can get into it tonight, I promise. Theres not a dam thing wrong with the bore tru set up, theres just better ways to do it in 2012, and its called CNC.

TripDeuces

Now where did I put that popcorn....................................?

cutlassefi

As usual you didn't answer my question. Glad to see you're true to form.
And I don't want to get into anything. I asked you a question and you didn't answer it, plain and simple.
Anybody see a trend here?

I put posts like this out for all to learn. If you have an opposing opinion and/or facts that's great, give it, we'll all learn.
Just be ready to back them up, again for all to learn from, me included.

citcapp

Please share with me. I am watching as well

joe_padavano

So is the boring done with the block undistorted and then the torque plates installed for final honing, or am I missing a step here? Thanks.

EDIT: Never mind - I just saw the answer to this in the other thread.

gearheads78

I'm going to take a stab at this. I'm not a machinist so I may be way off but here goes.
Your method uses a mechanical jig to put the holes in the proper location.

The CNC method does the extact same thing without a jig because it uses imaginary jig based on electronic axis positions.

Both methods end up with the same final result just different paths to get there.

ah64pilot

Happy trolling everyone Seems like we've been down this road before, at least once, maybe twice, but definitely not more than 10 or 20 times...

captjim

Hard to tell from the pic and I am an amateur, but the dial indicator in that position assures the proper angle of the deck from end to end?

It just stands to reason that everything starts from the align bore. If not, the pistons would be at different depths in the bore along with bores not centered over the crank journal. I am not familiar with either method, so if Marks and CNC both use the align bore to locate, OK.

VORTECPRO

Mark, sorry but I had commitments at work this morning. Let me again say theres nothing wrong with using a BHJ bore tru. Now to answer your question. When using the Rottler F 69 CNC bore mil. On a chevy we have a blue print of the block, this blue print can be found in the chevy power manuel. We first line hone the block, then we can then correct the cam tunnel if we opt to. At this point the probe can reference off the thrust or the the timing chain cover surface, the machine has the blue print specs programed, the next procedure is to relocate the head dowell pins in the correct spot, from there the trans mating surface is corrected along with the trans dowell pins, from there the lifter bores are machined, finally the cylinder bores are machine, and the nice thing with CNC you move the bores where you want them, or just to the blueprint spec. We have taken blocks machined with the BHJ fixtures, then CNCed the same block and there were differences. On my 455 build, Im not sure how to procede on the block because I have no blue print or program for a 455, Maybe Bill can help, but it might just have to be old school, thats not a problem for me.

VORTECPRO

Some people bore with a TQ plate, but most dont, because when you bore I leave about .006 to hone to final size, this gives you room to get the cylinders round and strait.

VORTECPRO

You will see every machining step I take with my 455 build, I will document the whole build. My question to you is: Will you even know what your looking at? I dont think you will......

VORTECPRO

Nick, Its probably a pretty good bet that I wouldnt have to borrow anything to machine and build a engine and then test it on the dyno then in the car. Just sayin.....

cutlassefi

If you have a blueprint for the Olds then that should work.
But even Bill locates off the dowels. As you've already eluded to, those aren't always in the right spot. That's what I've said from day one.
And I'll bet that on at least some of the plated blocks you've corrected they probably used the dowels to locate the plate. There are those who actually use a torque plate to center off of. That can be even worse.

VORTECPRO

I dont have the blueprint, but maybe Harold Bettes can get it for me, but that needs to happen quick, because its torn down and ready to be cleaned.

cutlassefi

One thing you forgot to mention at first was you ultimately use the cam tunnel dimension as well, not just the thrust as you made reference too.
You need some sort of reference for cylinder and deck angles, no matter what. There's no way you'll get that from the thrust alone as you eluded to initially.

TripDeuces

I think you both need to take a break. No matter which method you use you're going to have tolerance. I don't care if you're referencing off the mains, dowel pins or bores. Casting differences among blocks are all over the place as well as the differences in the crank throws, machining, head dowel pin holes, etc. What happens when you set it all up and the sonic check shows the bore to be shifted left, right, forward or back? Do you still bore it anyway because your method says so even though you've just thinned the bore in a certain spot? The variables here are off the chart and basically there is no perfect way of doing it. Quit pissing on each other over this stupidity. As long as the align hone is straight and the decks square you're good.
You want a perfect block? Get a big chunk of aluminum or cast iron and then use your method and cut it perfect. While you're at it do the same with a billet crank shaft because you'll want that perfect too. Don't forget to the heads also because if you want them exactly over the bore you'll have to cut them from scratch too. Might want to index the transmission dowel pins too so you don't wipe out the transmission bearings. Don't forget to change your cutting tools often too

I think I'm about done with that rant. Maybe you'll see my point. There's a reason engines come with tolerances and ranges in all the measurements.

380 Racer

Personally I like "Old School" methods that I know works. I know my engine builder likes perfection and he doesn't have a CNC machine.

SBORule

380Racer's old school method was, to put his block in the back of his truck and drive it all the way to New York to have BTR machine it for him. You just can't fix stupid! this member is living proof.

VORTECPRO

Personally Ive been impressed with Bill Trovato's BTR body of work from what Ive seen on these Oldsmobile forums, solid, good power, a very consistant builder, and he's a drag racer, that would be important to me. When it comes to machine work and engines it cant be stressed enough, get with the right people the first time.

Oldsguy

Well, I have seen some self moderation going on and that is good. But for others, you haven't been careful. Disagreements will happen, that's life but we need to remain civil. I am not closing this thread but was tempted to. Keep it civil guys.

380 Racer

You know Bruce, I have no idea what you post because this is what I see:

This message is hidden because SBORule is on your ignore list.

But if you run true to form, you were probably bashing me again . Someday I want to actually meet up with you and see if you would try to lie to my face.

380 Racer

Yes he also has an alias of mike1231. Pure honesty and someone I won't believe if he has to use how many names? He also went on my "ignore list".

cutlassefi

There's more here than meets the eye.

Milan..

Hers a 1956 Buick nailhead being set up for decking with a BHJ fixture. Motor will be a twin turbo , dry sumped and fuel injected for a Rad Rods by Troy customer !! Block and heads are fully polished.

gearheads78

Very cool. I have never seen a car built buy RRBT that I did not want to go over for hours and hours.