weak points to replace for high RPM

[Farkas70proof]

I want to know what parts of a 3.4 dohc need to be replaced to achive a higher rpm, looking for somewheres around 8k (give or take)... if anyone has any links, or info on what to replace with too that would help alot. Just for a N/A engine standard comp. ratio.

[SappySE107]

Stiffer valve springs and better connecting rods. Balance the bottom end too. What trans are you going to use cause the auto wont like it and the 282 wont like it and I dont know if the 284 will like it either. You will need cam work, head work, and intake manifold work to make power that high, and headers/exhaust would be a good idea too.

[Farkas70proof]

ss

thanks for the reply, I'm not building anything right now just trying to get some info since I'm justing getting into engine work. Probally going to school next year for it. it would probally be a 284, found some rebuild kits for one that should be able to handle it. Do you know of any good websites that have info and products for valvetrain componets for the dohc? seems like any performance sites only focus on 4 cyclinder imports or v8 muscles...

[SappySE107]

I sell valvetrain parts for the DOHC in the store. Josh and I are waiting to hear back from ferrea on valves and springs. 4.6 SOHC valve springs fit and are a bit stiffer than our stock and allow more lift before coil bind if you get a cam regrind.

Where are you finding a rebuild kit for a 284? They dont exist from what I know because of a contract agreement with getrag and GM.

[Farkas70proof]

after you said something I looke dit up again and I guess it was a 282 rebuild .. but I'm no too worried about trannies right now, I'd rather not think about it, lol

[Farkas70proof]

what about blueprinting? someone suggested that to me, but I don't know too much, all I know is that it's basically putting the enginge back together perfectly. Does anybody know of what kind of ridiculous RPMs the've seen from theese engines (still producing power of course)? also anybody have anylinks to engines that produce really high RPMS. I'd like to see what kind of parts and specs they run.

[Mach10]

"Blue printing" is making sure that every peice is fit together with much less fault tolerance.

For example, if endplay is listed as 0.006-0.013 you'd make damn sure it was 0.009. Also, making sure that ALL the torque-specs are bang-smack-on. Blue-printing makes for a more consistant motor, since you are cutting down the variables. Doesn't necessarily make it "stronger" per-se. I've also heard tell that some builders consider removing casting flash, de-burring, and port-matching to gaskets as part of a blue-print. How true it is I don't know... But I'm doing it anyway

Balancing is what makes the motor rev higher without scattering peices.


Also: Stronger rod fastners. The rod-bolts are the weakest point. Make 'em the strongest.

[Farkas70proof]

thank you both, I got enough to keep me busy for a little bit. When I get some more specific questions I guess I'll ask

[Dave]

I gotta step in here and add a little something ... I've heard the term "blueprinting" thrown arround so many times, that I asked an engine builder (Myron Cotrell of TIPS) what it actually ment, and he said the blueprint is put together, before you start building the motor, and it's just the plan you use when building it ... it will have a listing of *all* the tollerances, not just which tollerances you're going to use.

Blueprinting a motor is usually done when you're starting with a bare block and you're using almost all aftermarket parts. Almost all parts already have their tollerances listed when you buy them, putting those tollerances in one place will make your blueprint - much like building a house.

--Dave.

[Mach10]

Hehhehehe.... I have a book called "Blueprinting Engines." Along with instructions on how to take the appropriate measurements and explanations of different machine operations, the introduction warns that many people seem to think the way that Dave just mentioned.

A blueprint isn't just arbitrarily picking parts and deciding on clearances. A blueprint is taking the original factory specs and measurements and making sure that EVERY one of them is well within their margin of error (not too tight, not too loose.) Blueprinting can be done with stock parts, or aftermarket, as long as the aftermarket parts are within spec as defined by the factory. The net result of a blueprinted motor is that the number of variables is reduced, and the motor becomes as strong as it is possible to be because it is following the original engineer's specifications. It doesn't have anything to do with modifications.

Ideally, two blueprinted motors should produce the same power figures, and display the same reliability characteristics.

That said, many people make blueprinting to be more complicated than it is, but a great deal of people also just lay out a strip of plastigauge on a set of new bearings and call the resulting motor "blueprinted."

[HisCar]

Get this book-it is awesome! It has anything the diyer would ever want to use in building a motor covered. Actually strength and longevity are the main reasons to blueprint a motor- why do you think NASCARs 9+k 800 HP monsters are blueprinted to exacting spect down to the ten thousandth place? Because its worth it for them.

[Mach10]

That's the book I got! Best damn $20 I've ever spent. Tells you everything you wanted to know about engines but were too nautious to ask! Too bad I have a bad name for titles

But yeah, if you are even just thinking of rebuilding it yourself, get it... Even if you won't be doing half of what's in there, the installation tips alone are solid gold, not to mention the info on how to determine how boned various parts are, and how to fix them.

In other words: "Sweet book."