Billet main alignment honing question

[Pronto]

I understand that align honing is needed when billet mains are used. My question is if you only use the two centers and keep the stock front and rear mains as from the factory, can the honing process just work on the billets and not change the whole crank to cam relationship so the stock sized timing chain can still be used?

 

[rag231]

machining

That will be a question left to your machine shop. The least amout of material will probably be taken off, but I have heard..... " I need to make 1 more pass"

 

[bison]

" I need to make 1 more pass"

A good machinist wouldnt make that statement. You measure twice and cut once. The caps need to be line bored. The stock timing set will likely be loose. Id go to a .004 under and reference off that.

 

[Pronto]

So billet caps need to be bored not honed?

 

[LOT]

To answer your?

I understand that align honing is needed when billet mains are used. My question is if you only use the two centers and keep the stock front and rear mains as from the factory, can the honing process just work on the billets and not change the whole crank to cam relationship so the stock sized timing chain can still be used?

No and no

 

[Just a Six??]

So billet caps need to be bored not honed?

Both

 

[Pronto]

So boring or honing will take off both the caps and block and change the crank/cam relationship. There is no way to adjust boring so it would take off only on the caps?

 

[xsbc63x]

when i had my billet caps done the shop align bored it, however they were able to just take enough off the billet caps and not touch any of the other caps/mains.

 

[Pronto]

Exactly, that was what I was asking. So it can be done. I would imagine it's not standard practice from other's responses.

 

[xsbc63x]

not sure if its normal practice, but I would imagine any good machine shop would do it that way instead of removing from the block. ? ?

 

[bison]

Exactly, that was what I was asking. So it can be done. I would imagine it's not standard practice from other's responses.

It depends on more than the caps being used on the centers. The machinist may want to face off the caps to be sure they are sitting squarely in the register before boring. If you look at the factory mains they are not even honed. You see the boring bar marks on surface. Ive seen a lot of botched cap installs

 

[SCOOBY DOO]

So boring or honing will take off both the caps and block and change the crank/cam relationship. There is no way to adjust boring so it would take off only on the caps?

Line bore. A good machinist will take as little meat off the block as possible...and remove the most off the caps...the reason being the more meat taken off the block...the closer the cam/crank relationship becomes.

 

[BEATAV8]

"dropping the bar" into the block for the line bore is not a big deal, don't worry about it too much. Be more concerned about the final bearing clearances, straightness of the crankshaft, timing set undersize, etc...

I've used ANS performance, Windy City Machine, and Precision Engine & Machine and they all "dropped the bar" when doing a line bore. I even have a block that's been done twice and it has a -.007" timing set.

 

[Pronto]

Does the stock style tensioner make up the difference in the change if "the bar is dropped" with a stock style timing set?

 

[rag231]

machining

The "have to make one more pass" was a negative signal. Like Bison stated there is more than just running a boring bar thru the caps. It is machining processes like this that separate jobs that are done correctly. What is the big deal about you having to get a larger timing chain and wanting to use the stock plastic tensioner?

 

[Pronto]

There really isn't a big deal. I know a double roller can be had in different sizes and doesn't use the tensioner but I'm also curious about stock parts. I'm trying to understand the process and figured this is the place to ask. I had a V8 engine done once that was supposed to be align bored and all this and that. If failed miserably. The equipment the shop had was top notch but the operator wasn't. This shop advertises in national magazines and is supposed to be great with LT1s. I wouldn't bring him a lawnmower engine. In the future if I have an engine done I'd just like to be better informed.

 

[BEATAV8]

Does the stock style tensioner make up the difference in the change if "the bar is dropped" with a stock style timing set?

it probably would, but I'm sure you will be using a high quality roller timing set w/o a tensioner

ProGear makes exceptionally nice timing sets for all sorts of Buick applications right here in Chicago, with several undersizes available.

just a few:
for cast core cams
PG3134ST High performance timing set

for billet core cams
PG3132ST High performance timing set

 

[Nick Micale]

it probably would, but I'm sure you will be using a high quality roller timing set w/o a tensioner

ProGear makes exceptionally nice timing sets for all sorts of Buick applications right here in Chicago, with several undersizes available........

May be somewhat off-topic, but I cannot express how much I dis-like double roller chains.

Just removed this Pro gear from my car after 44 runs, most of them around 9.90.

The other 2 chains I have broken over the years were Rollmaster double roller chains.

Next set will be a stock-type link chain with steel gears and a tensioner.

 

[chopped39]

The engine shop I used in the past said that either heads or deck plates should be torqued down while line boring or honing. I dont know if that is overkill ot just good practice.

 

[Pronto]

May be somewhat off-topic, but I cannot express how much I dis-like double roller chains.

Just removed this Pro gear from my car after 44 runs, most of them around 9.90.

The other 2 chains I have broken over the years were Rollmaster double roller chains.

Next set will be a stock-type link chain with steel gears and a tensioner.

Do you have any idea why those chains broke? I thought the reason for a double roller was the extra strength needed for a roller cam with high tention springs?