has anybody noticed HP gains just from blueprinting(align honing,decking,torque plate honing,etc) their engine with no other changes?just curious if anybody has tested this or noticed an improvement after a rebuild.

 

You will see gains from compresion increases and reductions in quench volumes that are a natural result of blueprinting. If you include port matching and honing with a deck plate you will gain some there also.

 

Anything that you do to reduce friction ,etc will help power, not to mention longevity. How much gain depends on how bad it was before. The key is to check and fix if it is out of tolerance. Tolerance has different meanings to different people.

 

What about the strenght of the cyllender walls after honing?Will that decrease strength?

 

I have tested it over the years, generally you can get 20HP out of a correctly blueprinted short block over one that is not blueprinted. I think the term blueprinted is over used and a lot of people out their building motors don't really do it.
To blueprint a block you have to start by locating the transmission dowels to the main housing and cam bore.
Once these measurments are correct (corrected) you then check the head dowel locations to the cam and main housing locations and make any changes needed.
Once this is done you can measure the cylinder bore locations and correct them as needed.
Once this is done you can align hone the mains, torque plate hone the cylinders and then surface the decks 90 degrees to the main housing.
I think most shop assume most of these locations are correct to begin with and just align hone the mains, torque plate hone the cylinders, surface the decks and call it a blueprinted block.
I personally do it so I know my motors will live under the harsh conditions found at the race track.
As well it's a lot of work for 20HP, you can easily gain 3 times that by working on your heads and cam. Another reason most shops don't bother with it.
Next time you go to buy or get your block blueprinted ask the shop your going to how they do it...

 

Honing only removes a small amount of material No more than the thickness of a hair or 2 in most cases.

To the above list, you can add things like indexing the crank throws along with checking stroke, chamfering oil holes as well as deburring all parts and chamfering especially threaded holes in an aluminum block, to eliminate thread pulling, con rod work, port matching, checking lifter location and the list goes on.

Experienced builders know what problems each type of block is likely to have.

If the builder and/or machinery isn't up to snuff, the engine can turn out worse than before it was touched.

There are some decent books out there decribing the process, but the only way to know for sure is if you have the gauges, etc. to check the work.

When I used to build a lot of engines in the 70's, the shops that I used knew that I was going to check everything. On first visits to a machine shop, I would bring micrometers and dial bore gauges, etc and ask them to measure some parts (like cranks,etc) that I had already measured. I made sure that we were on the same page, so if I asked for something to be a certain size, they knew that it better be right.

Even so, on many occasions, I had to go back with my gauges to discuss a problem or prove a point. (Best to use good diplomacy)

Anyone can make a mistake, so if you can't check it yourself, then it is best to go with a shop that has a very good reputation with the race crowd.

Some shops are just NOT capable of doing high quality work , period.

On a high powered street application, there is no need to go crazy on this.

There is a lot that you can do to prep a block and other parts that can help ensure that you have a quality end product, but most of it is just common machining and finishing practices and will not net any extra power. It could however help avoid serious problems down the road.

 

Yes honing only takes about .003" off. Most machinist leave this amt. during the boring process so they can come back and take the rough surface down with honing.

 

i agree the term blueprinted is overused.i was curious to see if similar gains were found on a LS1 motor compared to a SBC using the same procedures.

 

I have a related question on the benefit of honing with a deck plate (versus without) on a cast iron block. I've bought a good used LQ4/LQ9 cast iron block that I'm going to bore and stroke to 408 CID. This is for a daily driver engine in a 3/4 ton truck and where things will be biased toward torque, not HP. I've already ported my heads and I will probably return to my 212/218 cam with the larger displacement.

Here's my question. Nobody in Wichita, KS has a torque plate for a this block, so I'm considering getting it honed without a torque plate once it's bored. I am going to have the main caps surfaced by about .001" and align honed as two of my mains are about .0005" oversize and the center main is .001" oversize. I'm also going to have it decked for a quench of .040". I'd prefer to use a torque plate, but I don't think that it's worth it for a single use in my application. What are your opinions?

Thanks,

Steve

 

it's a damn good idea to use a torque plate for the boring/honing. When the heads are torqued down, the cylinders will disort. If you bore/hone without a torque plate, your perfect round cylinders will go out of round when the heads are torqued down.

 

always use a torque plate...

 

I understand how the cylinder head fasteners (bolts or studs) distort the concentricity of the bottom of the cylinder in particular. However, this is much more pronounced on aluminum than on cast iron. Note, production LSx series blocks are not honed with a torque plate except for the LS7 and yet the rings do seat and the engines go for many miles (over 100,000 potentially) without problems. If I were going for all out performance optimization, I wouldn't consider honing without a torque plate. However, my question deals with a bored and stroked daily driver. Am I leaving 6 HP/4 pound feet on the table by not using a torque plate or what?

Steve

 

I don't know how the LS1 is on lifter bores but back in the 80's at the shop I started in we got in our BHJ lifter bore fixtures for SBC and BBC. We did 1 SBC and 1 BBC's lifter bores, thats it, nothing else was done. We picked up 18HP on the SBC and 30HP on the BB the best I can remember, don't ask at what RPM. We had a Super Flow and the boss liked doing this kind of stuff. From then on we pushed doing lifter bores on competition engines.

 

you are assuming they are using the same method or honing at the factory as the machine shop. Id guess that a correction was made for the absence of heads and there is probobly a thesis on it too

the real questions stands- 0 or 100 hp, why WOULDN'T you use one?

 

Trey,
The reason is that no one locally has a LSx series torque plate in town for bores exceeding about 3.95 inches. This would force me to buy a torque plate for a single use if I have it machined locally which I prefer to do.

Steve

 

was this done to correct alignment between the lifters and valves, i.e. better geometry?

 

Bores can be off several degrees. By truing the bores the lifter angle is in correct relationship with the cam lobe.

 

that's what i thought.thanks.

 

Well as i see it, Chevrolet has things machined pretty damn close as i see they run around .014" top moly ring gap for a spec. Bore shape cant distort much when in running condition, with out these specs causing a problem with butting of gap ends. Gm also reduced main bearing clearances in 2001, this also requires precise machine work to pull off in production. I went thru my LS1 (for dreaded piston slap) and i was impressed at how everything looked, and fit. The replacement coated skirt piston has Thermal barrier coating and anti detonation grooves, very nice in my opinion. Runs like a chain saw now with a good tune up!

 

Just wondering, what are anti-detonation grooves? And, when did they start having them? Thanks.