TOPIC:

What exactly does this mean? I've only seen brief references to this being done, but have no idea what is involved. Has anyone on here ever had it done? If so, what is the going rate, and does it make a noticeable difference in engine performance? Thanks in advance for any input!

I was typing my reply out and then realized someone on yahoo questions said it better...

When an engine is built, the manufacture specifies a "tolerance," or range, for the dimensions of its parts. Blueprinting means carefully measuring all these parts, and then if necessary machining them to make sure they're the best size or weight for performance.

For instance, a valve stem and a valve guide will be specified by the manufacturer with tolerances that allow for a clearance between them. If the clearance is too small, the valves may bind or stick, which can cause engine damage in some cases but will at the very least lead to a loss of performance due to the friction. If the clearance is too large, too much oil will flow down the valves into the cylinder and the spark plugs will foul. So "blueprinting" the valves and guides would involve carefully machining the valve guides to the BEST clearance, not just to whatever clearance happened to be there by picking a valve and a guide that were both "within tolerance."

Blueprinting is often used in conjunction with "balancing" an engine. The idea is very similar: balancing makes sure that all parts of the same kind have the same weight, down to very small tolerances. For example, a set of connecting rods may vary in weight; a balanced engine will measure the lightest connecting rod, then machine off tiny amounts of metal to make all the other rods in the engine have the same weight, down to a tenth of a gram. A balanced engine runs more smoothly, especially at high RPMs where an unbalance would be likely to cause extra wear on the internal components.

Scott F.

Thanks, Mean Green. I had read that, but was wondering if there was any more to it. I assume, then, that blue printing a head would involve balancing the valves (anything else?). I'm curious about this because I need to get my head rebuilt, and while shopping around, I was given a quote of $800 + parts for valve job, blue printing, port, and flow. I asked what was involved with blue printing, but never received a response. It seems as though balancing the connecting rods would make a significantly greater difference in performance, compared to balancing valves (at least, to me).

Let me know if I'm off course here; again, I'm just trying to make sense of this and weigh my options. For what it's worth, my Z1's engine is stock, with no other modifications; I don't race it, and usually take it easy while riding, which is why I'm trying to determine if shelling out that chunk of change is worth it. Thanks again for any input.

For what you are using it for a three angle valve grind and possibly valves, guides and seals will do the job. A good mid range cam will up the performance too. There are lots of people that will gladly take your money for something that you don't need or doesn't exist.
A truly balanced motor can last longer and deliver more power but I doubt it's worth the extra money.
Steve

Unless absolute maximum performance is your goal, don't do it. Based on your riding style, I would say you'd be wasting your money and may in fact regret it. Porting (and the associated increased flow) can make significant changes to the engine's power output. However, maximum power is not always a good thing. Porting for a drag racing application may make it scream at the very upper end of the RPM's, but decrease power below 5,000 RPM's. Great for the drag strip, but a major pain to ride on the street. You want useable power for the type riding you do. Just get a stock rebuild with good valve seat and stem seal.

Anything blueprinted is just built to the original factory design specs (the blueprint) and will be pretty much to the standard as it should have come out of the factory.
A simple valve job and new guides will be plenty good enough.
As for balancing valves there is no such thing unless you mean balancing the carbs ?
You could weight match the valves but there would be no advantage as opposed to weight matching the pistons or balancing the crank for slightly smoother running.
In a std motor the whole process would mostly be a waste of time and money.

I would also add replacing the valve springs. They can test good but have issues while running. / Well worth the $65 for peace of mind.
Steve





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Thanks for your input, everyone. You've affirmed some of my own apprehensions. The guy who gave me the quote is a friend of my brother's, who runs a performance shop on Long Island. I trust him, and his work is excellent, so I think ultimately he may just be prone to suggesting such an extreme amount of work.

As suggested, I think I'll stick to the grind, valves, guides, seals, and springs. Besides, I've never really been a fan of doing things that can't be undone.

Zed1015 - your definition of blueprinting was the one that was familiar to me before I got into this. It didn't make sense to me how "blueprinting" according to that explanation could possibly warrant an extra $400-$500 beyond the typical valve job.

swest wrote: I would also add replacing the valve springs. They can test good but have issues while running. / Well worth the $65 for peace of mind.
Steve

Where is a popular place / brand to get new springs?

Bragging rights.
Steve

You're such a tease, Steve.

neighbourdave wrote:

swest wrote: I would also add replacing the valve springs. They can test good but have issues while running. / Well worth the $65 for peace of mind.
Steve

APE directly from them or Z1

Where is a popular place / brand to get new springs?