There are a lot of shops and back yard garages that should not even be aloud to have a tool box.

Look at the budget builds that go bad. Hyper pistons used where a good forged piston should be used. Cast cranks where a good forged crank should go.

And the biggest issue with idiot shops is boring off unsqured decks if the shop can't deck the block without taking of the VIN number you better find a shop that can.


I have leaked down a lot of newly built engines this past year that have had up to 40% leak down because the budget build required it or the shop doing the work does not have a clue how to prep the cylinders for ring seal.

There are a lot of shops using substandard equipment to do performance work look at some the rinky dink cylinder hones being used they surely can't do what a sunnen hone can do or the new Rottler hone. Sunnen has the best abraisives for honing. There is good power to be made with good cylinder prep. Ring seal is key when your looking for HP.

Look at GM main lines after thousands of heat cycles they may measure OK but now the problem is alignment I see it all the time the bearings are down to copper up at the parting line. So far I have never been able to cut a GM main cap .001 and line hone the block and have it true up every where if that tell you any thing. Its funny I can cut the caps on a Dart block .001 and it will clean up every where HMMMM

Look at these forums they are full of low oil pressure issues, rod knock issues, bearing issues, blowby issues, oil leaks issues, cam lobe issues, Vibration issues ETC, Just do a search and you can see what I am taking about!!! Most of the problems are due to poor machine work or lack off.

Go to a shop that has a good reputation for good work and customer service and are using good equipment is key. If you go to the local jobber shop for a performance build its not going to happen you get what you pay for.

Jobber shops do good at building bone stock engines that what make 175 horse of so.

 

My freinds shop is expensive but he always has work. He has his own building with huge amount of space and every machine needed build engines.
He square decked my brand new Mowtown block because it wasn't the same meausrement corner to corner and so on. He opened up my valve guides on my brand new AFR heads only about 1 thou but he said AFR makes them on the tight side and AFR will tell you that.

He had to re-size the big end of my brand new forged H beam stroker rods because they were egg shaped. He polished my brand new Callies crank.

There is more that he did to brand new parts, not to make money but because this how he builds engines and when complete he say " Now take it out and beat on it" and they do and they don't blow up. So there's a huge difference between crappy shops and good shops and it ends up you get what you pay for.

How many shops out there do you figure would check and fix all this and time is money that's why he's expesive but the balancer won't fall off on your garage floor when you get it home, anyone remember that one ?

 

I Have one of those guys locally. Block was zero decked, Bored off the square deck, plate honed to size, New billet caps fitted, Line bored and honed, He found the same issue with my new AFR heads They werre disassembled, cleaned and checked, guides opered up, valve springs checked and resetup. The callies compstar rods were right on both in size and weight on big end, small end and total but checked. Balancing is one area that many builders get it "just good enough" since you can weigh the pistons and equalize them same with big end and small end of rods and the crank and assembled components can all be ballanced to a + or minus tolerance. This acceptable + or - tolerance varies from shop to shop but is critical to longevity especially at high RPM's. Closer the better. My suggestion to the OP is if he trusts the shop have them do all the machine work, assemble the shortblock and inspect the heads since they have all the knowledge, tools and measuring equipment to do it right. If you feel uncomfortable with the shop find another one. Building the rest of the engine is an assembly procedure that you can do in your garage with some research, is a good learning experience and you will have a sense of satisfaction when your done.

 

I have built a few engines and If Im not racing for every 10th I use cast to last a long time.
My machinist/builder will not use "hypertech" pistons and has a whole box of ring land broke pistons as his reason why.
You can't go wrong with forged pistons and have the whole assembly weight matched and balanced.
I have even weight matched cast and they work fine.
But the area your from all does it different and for different purpose engines.
Its so technical for bore or hone, file to fit or cast rings to chrome rings, that your builder has to have the experience to know what works together.

 

Those are two entirely different design pistons ... and will yield vastly different compression ratios.

L2256F is a forged flattop with 4 eyebrows aka valve reliefs and has an effective dome volume of NEGative -6.1cc (think of it as dished) This will get you close to your stated goal IF, IF you run 64cc chambers ... Not 76cc.

H618CP is a hyper with a small dome with an effective dome volume of POSitive +3.5cc. This will get you close to your stated goal IF, IF you run 76cc chambers ... Not 64cc.

That's nearly a 10cc swing!
You should settle on a combustion chamber size Now and before you choose a piston ... that's gonna be a lot more important now & later; more than debating shops' professional ideology.

also, Silvolite pistons are made by UEM, the same maker as KB hyper ... thanks but No Thanks.

here's a handy, accurate static compression calculator from the maker of both pistons you've considered above. Federal Mogul aka Sealed Power aka Speed Pro fka TRW.
http://www.fme-cat.com/Calculator4.aspx
G'Luck

 

You have 4 options for pistons.
1. Cast, Used on stock, low performance builds and rebuilds Low expansion, Tight clearances. Least expensive.
2. Hypereuectic, Stronger and more durable than cast and can handle more power and a small nitrous shot. Low expansion, tight clearances, Whatch ring end gaps, Would avoid KB/Silvolite, Used on new corvette engines. Slightly more expensive.
3 Low expantion forged. This would be your Mahle Powerpack refered to earlier. Also manufacured by others. 4032 alloy. High silicon, low expansion, tight clearances, stronger, more forgiving to detonation than the cast or hyper, tight clearances Higher price. Used in many modern, high rpm, high end sports car engines. about twice the price of cast.
4 Forged. These I would consider racing only pistons for High compression, boosted or heavy nitrous engines whose goal is high HP high RPM operation. 2680 alloy, no silocon, softer, most forgiving to detonation, big clearances, noisy when cold. Price varies from same price as low expansion piston price and up.
I would use a hyper or low expansion forged in most 1 hp per ci to 1.3 hp per ci builds depending on power output and intended use.

 

The stroker rods that were egg shaped on the big end were from Eagle, they have the shoulder machined down to clear and that means the bolt is also milled down on an angle, once you get them resized now the bolt needs an extra 1/4 turn almost eliminating any benefit from the cut down shoulder because now the bolt sticks out a little. My buddy ate the 4 in. Eagle crank that wasn't straight, the last Eagle part I'll ever buy.

Callies Compstar cranks and rods are right on the money even though they start out in China Callies has very good quality control over these parts and would not hesitate to put either in my motor. You move up to a Dragonslayer, Magnum etc. and everything is done in the states. And theses are good pieces, the Ultra Billet crank is so purdy you want to put it on your living room table instead of installing where no one can see it.

 

I used the calculator you linked. Figured 4.030 bore, 3.48 stroke, .010 deck clearance, .040 compressed thicknes, 4.165 gasket bore, 72 CC heads, and -7CC flat tops and I came up with 9.97 to 1 compresion. No way to use 64 CC heads unless he goes with a dish piston. This also gets you .050 quench. I like a little tighter than that but it would work. The head gasket I figured is a Felpro MLS Q1143.
On the KB and Silvolite pistons I would not use them. Just been to many failures. It is kind of like the XE flat tappet cams. There are many used and they have had no issues but there are also many failures. It sucks to be one of the failures.

 

Op, ph # 207-892-7215

 

close spelled C-L-O-S-E

 

I can see there are a few smart guys here

If you use quality parts and have quality machine work done in the end you have a quality engine.

Build a budget engine with budget parts and budget machine work you some times get what you pay for

Look at the guy where his engine lasted 84 miles and let go and look over his previous link HMMMMMMMM

There was a guy a while back was pulling his engine for the 3rd time.

A good machine shop will help any customer get there engine together and give him or her some guidance.

 

I throw these pics up occasionally to illustrate what good machine work can get you. This is my 10 year old 540 that regularly spins 7500+ rpm and more than I like to admit well above that. The bearings could have all been reused, the pistons (SRP 4032's) still look like new..and you can see no combustion deposits below the top ring. This engine took quite a few cross country trips and tons fo regular street cruising miles. No noise or oil usage (even though I ran the pistons looser than recommended specs) and great oil pressure.

Really good machine work can help lesser quality parts live a long time. Good machine work with great parts is unbeatable. But sloppy machine work will produce shrapnel and troubles no mater how fancy the parts!

To the original question...I'm not a Hypereutectic fan. The stuff the OEM's use is light years better than most of the stuff you normally see. Plus they have all the electronics to control detonation and A/F ratios. I always err to forged anything over a hyper anything for street toys. If it's a pure $$ issue...I'll find a way to get the better pistons. Cheap pistons are false economy and WILL bite you sooner or later.

I'd trust genuine OEM stock pistons out of an old motor before I'd swap in most hyper's in the aftermarket.

JIM

 

Let's see...that 84 mile engine was done by a "professional" shop - not a guy in a 2-car garage Sounds like just a BAD shop...of which there are many. As noted previously, big shops can do garbage work just as small shops (and home builders) can do outstanding work.

As always the word "budget" gets branded with "garbage" - basically the position that if you're not spending $15,000 on an engine it's going to explode.

Not everyone needs, wants or can afford a $15,000 all forged, blueprinted engine making 500+ HP. No question that a quality machine shop is job one...but a cast crank, hypereutectic piston engine can be a great engine at an attainable price and still deliver decades of outstanding performance and durability.

 

Who is building 15000,00 all forged engines I would like to get those customers.

Cast cranks who really uses those any more and HYPER pistons

Are you one of those 2 bay garage guys LOL


Sounds like you push budget machine work and are one of those guys who has his cylinders bored off unsquared decks. LOL

 

FWIW, the only reason I'm a "2-bay garage" mechanic is because I lost a 4+ bay shop thanks to the one-two punch of economic hardships and a rather expensive divorce. Given certain choices, it seemed the right thing to do to try and keep a roof over my head. Thing is, I was "engineering" and assembling one-off racing and high-perf builds before many an expert here could probably even drive, and still have plenty of good connections in the Memphis area performance industry, so this particular 2-bay guy would appreciate not being lumped into the stereotype of DYI'ers being implied here.

 

WOW talk about a thread that has got out of hand and totally for got about what the question was by the OP! Yea I got caught up in it also! My original answer here is the only one I want to claim and that was to follow the Factory's lead on this. Up to about 325HP cast is fine
(not hypers either) after that run a forged piston.



AND ANYONE ANY WHERE CAN BUILD CRAP OR A VERY FINE ENGINE regardless of size of the shop and where it is located!!!

Sorry had to say that!!!!

 

To a point. The power window for good hyper pistons is narrow. I would say 300-400 hp in a small block with a very safe A/F ratio and conservative DCR and timing. They don't like any detonation. A low expansion forged would be my choice for almost any street performance build. A regular forged piston I would reserve for a race only engine. JMHO

 

That surely hurts best of luck in the future

 

I remain surprised by you on a number of levels.

First, how can anyone working in the industry be so completely ignorant of what's happening in it? By far the largest majority of GEN I SBC builds today are being done with aftermarket cast cranks and hypereutectic pistons. The cast-crank 383 is probably the single most popular GEN I build out there today. But you run a racing shop, and so anything that's happening outside of that you choose not to know about. There's a whole world of engine building you clearly just know absolutely nothing about. Ignorance breeds contempt.

Second, you appear to have a good shop that only does high-end, racing-type builds. You could come on here and other forums and add a lot of value for folks doing those kinds of builds. Instead, about 99% of your posts anywhere are nasty cracks about anyone not doing a high-end build. What's the point?

The reality is that you're attacking about 99% of the folks on this forum and elsewhere...and just proving the point once again that the last shop anyone should go to for a street performance build is to a racing shop - especially one with such a crappy attitude.

Hey...is this your business address: Hinkson Automotive, 20 Vista Dr, Windham, ME 04062?

 

I Think you maybe the one thats ignorant here as the newer engines of today have engine management systems and are all computer cotrolled and it would be pretty hard to hurt any piston or crank in that enviorment

CNCBLOCKS NORTHEAST and Hinkson Automotive Reseach and Development bus. address is at.
18 Mitchell Hill Road
Gorham, Me 04038

My trucking business and Engine shop is at 20 Vista drive.

Have not attacked any one that I know of But myself and few other here beleive in doing things the right way which is the only way as its 2012 not 1960 Things have changed alot over the years.

I deal with a lot of top shops all over the U.S. and Canada and I know what they do for work and what they are using for quality parts!!!!!

Quality parts and quality machine work = a quality engine

Substandard parts and machine work may equal disaster and not run as well as the quality engine.I have seen this to many times Just look at these forums as they are full of problems mostly because of budget builds and shorty machine work.