In my mind, anything that's worth doing (especially with high dollar engines) is worth doing right.
That includes checking every measurement: every bearing clearance, every piston/cylinder clearance, putting the block decks where you want them to get a parallel/square deck, etc, etc. There are a myriad of steps to ensure an engine is "perfect".
It also includes checking the rotating assembly balance. You can't mismatch aftermarket parts without doing it. Aftermarket crankshafts can be used with factory rods/pistons or aftermarket rods/pistons and every combination will have a different bobweight.
All of this contributes to a smooth running, solid engine...
Anything not checked could contribute to an engine failure.
Anyone can put an engine together....only a few are engine builders.
Cobra Make, Engine: ERA 289 FIA #2100 Rio Red Wimbledon White Stripes 302 stroked to 331 Webers Richmond Road Race 5 speed
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I could have built my own, but by the time I purchased all the micrometers, dial indicator, cam degree wheel, ect, ect, it was easier to let some one who does it every day with a few tricks up his sleeve and years of experience. After spending all the time and money on the best parts, Scat forged crank, Crower Sportsman Rods, AFR heads, and JE pistons, I did not want to take a chance forgetting something stupid and have the engine take a dump. Definately balance and blueprint the parts, for a few extra bucks it is well worth it.
If I were rebuilding the engine in my beater 88 Ford Ranger, different story. Better yet, go to a bone yard and buy a used engine for $400.
Cobra Make, Engine: RMC under re-construction, GenIV with tremec 600, Jag 3.31 L/S diff
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Quote:
Originally Posted by spookypt
For those that are building new, or have built their own engines in the past...... do you/are you going to balance and blueprint your powerplants??? Spookypt
Absolutely.
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I'm curious Les as to whether the aformentioned names had done this???
Its expensive I know but when you consider the cost to do it versus the cost to replace should it go bang it works out to be FOR ME about an 8th the replacement price!!!!!
I assumed anyone spending big dollars on an engine would do this - if only to allow it to rev more freely! What proportion of the total cost would it account for?
Cobra Make, Engine: RMC under re-construction, GenIV with tremec 600, Jag 3.31 L/S diff
Posts: 3,318
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Quote:
Originally Posted by spookypt
I'm curious Les as to whether the aformentioned names had done this???
Its expensive I know but when you consider the cost to do it versus the cost to replace should it go bang it works out to be FOR ME about an 8th the replacement price!!!!!
Worthy insurance!
Matt, to me it is more than worthy insurance. It is double checking all the components of the build. Take windsor flywheels for instance. There are a couple of different balance weights and one needs to make sure the manufacturer has not got it wrong.
Any engine seeing some high rev duty will be more durable if blue printed and balanced.
__________________ It's impossible to soar like an eagle when you're surrounded by turkeys.
Matt,
This should not be a decision you need to make, most definitely everything should be balanced all tolerances checked and then double checked.
The engine assembly area should be clean almost surgically clean, all parts must be cleaned and parts with sub assemblies should be pulled apart cleaned checked then assembled before installing into engine, eg Oil pumps, pickups etc.
Care must be used when put together, piston to value clearance must be checked and rocker geometry must be perfect.
Spend the time and degree the cam a degree here or there makes a lot of difference.
Always use solvent based oils.
Use a good sump with gates, and install an oil accumilator.
Well that’s what I do, the motor in my cobra has 485RWHP is 5 years old and as most people would know I am not shy to give it a hiding, I put it on the dyno just before the nationals and it still makes the same power.
There is so many aftermarket parts available these days, so when building a windsor use a Dart, world or SVO block, spend a bit more on a billet crank and some I beam rods.
Phil
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Not all driveways reach the street!
Spook, Pete's engine went bang because a harmonic balancer bolt came loose and the balancer moved off the crank causing it to tear the front of the block apart. And yes it was balanced. Wayne's engine didn't go bang it just developed a water leak in the block so he replaced the block with a dart block. used all his original internals. (apart from bigger pistons for 4.125 bore) I think Denis engine was about 20 years old like mine and didn't agree with the pressure the supercharger was putting on it.... Not sure about wazzas antploding engines...
Absolutely a must if you get an engine built is to B&B it.
My current engine ( 347 Windsor) revs smoother than any engine I've ever had...Zero vibrations...it's brilliant.
BUT...
I have to admit I did have some probs with engines ...that's for sure.
But they can blow for the dumbest reasons....
I lunched one engine, even though I recon it had been built beautifully, went like the clappers, and was completely balanced and blueprinted.....all it took was a series of little mishaps.
I overrevved the engine , when I lost all grip momentarily accellerating out of the pits onto the track, with slicks on a wet patch at Queensland Raceway....
Poor little 302 Windsor went to about 8250 rpm instantly, and broke a little piece off a valve spring.
That tiny little bit of steel found it's way to the sump.
This is where the second little mishap had happened unkown to anyone.
At the post mortem it was discovered that hidden out of sight in the sump, the gauze cover/ filter over the oil pick up had broken off....
probably didn't allow enough clearance when the sump was put on...
and with the gauze filter sitting in the bottom of the sump doing F'All , the oil pick up took that tiny little bit of valve spring up into the oil pump.
That bit of spring then got jammed in the oil impellar...seizing the oil pump, and turning the oil pump drive into a cork screw....no oil getting into engine...then as I was trying to stop , the corkscrew jammed itself against the conrod ....everything stopped turning instantly.....and within a very short space of time I had a shagged engine.
All that balancing, and using all of the very best ( and expensive ) engine components, all went down the gurgler when that little bit of spring got sucked into the oil pump.
The NEW engine has also been balanced and blueprinted, and there is now a rev limiter always in place, and I triple check everything all the time...and it has been excellent.....
TOUCH WOOD.
I once saw a Queensland based engine builder (no longer in business...) that offered a blueprinting option for an extra $100. As Brent and Phil touched on, the amount of time spent ensuring that all tolerances are perfect proves that anyone claiming to do it for a lazy hunge are kidding themselves.
By the end of this video, it's fair to say the engine is more than a little bit out of balance...
Cobra Make, Engine: Kirkham 427 brushed aluminum with Keith Craft 527C.I. all aluminum FE
Posts: 992
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I would think that a y engine of any kinf would be balanced and blue printed. This is just part of the standard procedure with us. When you use CNC machines and measure all of the components right you will have a blue printed engine. I would never put an engine together with out balancing it unless every part came with the engine originaly.
We balance every engine as well as check every tolarance. Our state of the art machines help us do this at a reasonable price, just have to spend about a million to get there. It just cracks me up how people will try to save 500.00 to 1000.00 when doing an engine and it would have been much easier and less expensive in the long run to do it right with someone that knows what they are doing.
Parts do break and when you race engines you will find what part is the weak link. You just have to build the engine with the right parts for the application. Do not lie to your builder or think that you can get by with cheap stuff in a high performance engine. Do not cry to anyone if you use second rate parts and machine work when it does come apart.
Had a conversation with one of my customer today that is a plumber. He gets the same amount an hour that I do but complains about what this engine stuff cost. I have about 1.5 million more invested than he does, but I guess that makes me the dumb ass and him the smart one. As I have said before you have to love this stuff to be in the engine business and like to work many hours to make it.
We also supply a parts, bobweight, balance, head assembly, engine assembly and dyno sheets with each engine. More paper work than you get with about anything else like this. Then it kills me how many people lose it or have someone interested in their engine and they call us for the paper work.
All in all I think most people have pretty good luck with the engines in their Cobra's.
Engine balance and blueprinting???
Ooorrrr you
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