I took my crank in today and got it turned 10. The machine shop is very reputable and stated that my engine had some line bore issues based on the crank's condition. He also said that the intake and exhaust valleys prolly had something wrong with them. I was curious if anyone knew exactly what this means.

I was planning on doing the rebuild myself, however the shop said it would only cost me 280 more to have them build the shortblock instead of me doing it myself. I feel as though they are very qualified, I just felt out of the loop with the terminalogy. I already used the search feature as well.

Thanks!

Kendall H.

 

intake and exaust valleys? You sure you got the terms right? Just how reputable of a shop is this, you talk to other racers or you just see alotta people go in and out of the place? Sounds like they wanna rape you on machine work and talk you into letting em build it for you. Sounds weird.

The crank may be worn funny and have a condition an align bore may fix, but ive heard of an intake valley (area under your intake where the lifters sit) but never an exaust valley??? What your intake valley has to do with your crank issues is beyond me unless they thik its cracked or something. Either you got the terms mixed up or theyre trying to jerk you around.

 

Very reputable. They are a bunch of old timers. I more than likely got the terms mixed up. However the machinist mark told me clearly that my block has a line hone problem of some sort and would like to look at the block to see what it is. I forget exactly what term he used for the intake thing. He knew that my crank came from a 94 engine without even seeing the engine or knowing what year car mine was from. A fluke, maybe, but i doubt it. He is a great guy to work with and I trust him 100%. I was just curious on the terms and what line hone exactly means. I thought you would bore the block to whatever specs and then with the pistons/rods you can then hone the block to meet your pistons specs.

However, the term line hone just through me off. Did he simply mean that when it was honed, is was not honed for the correct pistons?

Thanks!

 

He is probably referring to the actual crank bores that the crank sits in. $280 is a pretty good price to assemble a motor as long as they don't discover any other problems. If you havn't much experience and few tool, I suggest letting them do it

-Shannon

 

Ahh, gotcha. That makes since.

Because the price is so cheap I think I am going to just have them do the work. Plus it needs to be balanced so if I built it I would have to take it back to them again. I have all the tools, feeler gauge, dial bore, micrometer etc, well actually most are at my pops house, but I have access to them. However, not having to hassle with the engine and knowing it is going to be done right is a good piece of mind. I have very little garage space as it is and this would help out a lot. Plus the wife wouldnt nag at me!

Thanks again for the info.

 

Basically what he is telling you is one or more of the main bearings for whatever reason isnt lined up right or cocked slightly. Basically they dont all line up starit and true. What they do is rebore all of them slightly larger and put in bearings that make up for the now slightly larger holes. I would deffinatly do this while the motors torn down, dont put taht motor together without doing this. Consider it mandatory repair work.

 

Align hone is the machining done to where the main bearings sit (between the block and caps). It is a must when you fix new caps or change the type of cap retention, and in your case if there are issues. You may have mixed up the terms with the valleys for the lifter bores.
If you trust him go for it, this is not expensive for having him fix, clean and most importantly check the tolarences.

 

"Line bore" and "line hone" refer to the main bearing saddles where the crank fits. Actually the terms are "align bore" and "align hone" because you want all the main bearing bores to be in line or "aligned". This has nothing to do with the cylinder bores.

Usually the only reason to align bore is because you have changed main bearing caps from 2-bolt to 4-bolt for example, or from cast iron to steel. The new caps come significantly undersize. Each one has to be machined with a cutting tool to get it the same size as the half of the bore that's still in the block without really cutting any material out of the block. The trick is getting them all in line, so fairly expensive fixturing is needed.

Align honing finishes up the sizing of the main bearing bores after align boring, or if the original caps are used, the honing is done without the boring. The main caps are removed and a few thousanths (.001s) of material is removed from the faces that mate to the block. Maybe the thickness of a sheet of paper or two. This makes the main bearing bores "short" from top to bottom but still the same width. Now the align hone fits into all 5 (V8) main bearing bores at the same time. It is rotated and stroked in and out while the honing stones are expanded. Most of the material that is removed is cut from the shortened cap. Very little is removed from the block, so that the crank centerline doesn't move up much toward the cam bores. The hone likes to make the holes round and the shortened cap gets most of the removal. The bore does move up a little, but only avery few .001.

The hone not only sizes the bores back to stock size (at least top to bottom), but more critically, in puts them on the same centerline (or aligns them) so the crank won't bind up. You don't need oversize (on the outside) main bearings because the correctly done align bore and/or hone doesn't alter the main bearing bore size. Sometimes this is hard to visualize, but the hone cuts where the extra stock is. How do it know?

Usually align boring is more costly than align honing, but if you bore you must also hone. In your case, I can't imagine a need to align bore, but the align hone might be necessary. The shop should be able to check the block and show you where it's out.

As for the intake and exhaust "valleys" I'm mystified. You might ask for a clarificatiion.

FWIW, I think you ought to have someone assemble your engine for you.

 

OldSStoker: That was a great explanation and very detailed. Now since I know what the definition means I can clearly explain what needs to be done. It sounds like they are going to align hone the block after they bore the cylinders and recieve the pistons/rods. They said that if I wanted I could stop by before the block work was done, take pictures or what not and then after it was finished i could come by again and they could show me exactly what needed to be done and take pictures etc. I havent talked to them since yesterday due to the fact that I need to take my block in for them to check. However, once I take the block in I will give you an update if you are interested. I will also ask them about the intake valley thing. Since they are going to be building the shortblock I imagine they will let me know everything I will need to bring in so they can assemble it and balance it. Its been 4 months since I have had the car out of commision and I cant wait for it to be all together again.

Once again thanks for the clear description. I couldnt have asked for better.

Kendall

 

Generally you would align hone the main bearing bores BEFORE boring and honing the cylinders. The main bores are usually used to locate the block. This is important because you want the bores square to the mains.

If you can "talk the talk" with some understanding you'll get better treatment and less bovine scat (BS). Informed consumers are better to deal with. The problem lies with those who get a little information and think they know a lot more than they actually do.You don't impres me as this type.

Good luck. Keep us all posted.

 

Hmm.. I talked with the man at the counter and he stated that I could bring in my block and see what the block could be bored to and then he could bore the block prior to me recieving my pistons if i wanted and then he could hone the block when the pistons were recieved. However, he said that he would rather have the pistons in hand so he could match the cylinders to the pistons. (So from my understanding from what information you have given me, he would align hone the block then bore the cylinders and then when he recieved the pistons he could hone the cylinders.)

The long story of things is that I purchased a lot of performance mods and now I am short on cash for the block buildup. I know, I did it backwards, but I recieved good deals on the items so I couldnt pass them up. Anyhow, I now am trying to save up some cash for the summit forged piston kit. I explained this to the machine shop and he said "thats fine just bring in the block so we can see what the block can be bored to and what else may need to be done, and then we can do the rest of the block work when you have the money to purchase the pistons.

I am defiantly far from knowing anything relating to block work, that is why I find it important to have a competent machinist doing the block work for me. Unfortunantly in order to find the right machinist I have to understand the terms that they are referring to and what order you should do these things. As of this time I was under the impression that the machinist would need to look at the block and decide how much they could bore the cylinders to and how much material they could take off of the main bearing area to make sure the crank seats well and that they do not have to use over sized bearings. I was also under the impression since I am planning on using my stock main caps that they would need these in order to check them for straightness and durability etc and do the required machine work necessary.
In what order each needs to be done I have no idea. I am not a machinist, however I would like to know so when they are trying to have an intelligent conversation I can follow along.
I purchased the book "How to rebuild LT1/LT4 engines" in order to try and understand more about how this works, unfortunantly they just have detailed instructions on how to remove/install the block and leave the machine work up to the machinist. If there is a better book or place online to find information pertaining to machine work on blocks in general I would appreciate any foresite.

Thanks again for the info!

 

Take everything to the shop. Give them a couple of days and check back with them,they will tell you what you need.
Sounds like they are good guy's so trust them to do it so it won't come apart next month and cost twice as much to fix.
If you are running close on money they will work with you and not try to do a bunch of stuff thats not necessary. But they have to do the things that will make it stay together,seeing's they are putting it together.