Balanced & Blueprinted

By Gene Bellegarde

All serious 'race' engines are 'balanced and blueprinted'. Blueprinted means designed/re-designed by an engineer to meet exacting specs required for the particular job it will do. An Indy engine is designed such that it will run 600-1000 miles, then thrown away, never to be raced again. A drag engine is only good for up to 10 runs or so. Things considered are align boring for the cam and crank placements, clearances/tolerances of moving parts to each other, etc. A race engine will use almost ALL remanufactured parts, special drop forged rods (hot rods), hi dome pistons for compression. Stringent flatness specs for the block and head, on and on. The specs are on the 'blueprint'. When clearances are reduced for more accurate relative movement, high pressure oil pumps are needed to push the oil into these smaller annuluses, often thicker racing oils are used, etc. If you are running 500 + HP, [the oil is what keeps the bearing insert off the crank journal,] it is trying to get there 8+ times more than in my 175 hp 142E 'racing' engine. The 500 HP engine needs a high pressure oil pump. Perhaps the engine that Dave Palmquist had in his SCCA autocross racer needed one, because he pushed it hard every weekend on a slalom course somewhere, almost never drove it 'normally.' Different meaning of the word 'racing' altogether. If you are going to attend events and take it to work on Fridays, plus run on a track at the West Coast Convention, that is not the same 'racing'. Having more hp is fun, and you CAN afford that pump and the valve springs, but what I'm talking about is the heartache of doing the building, having fun, kicking butt on Skoog and Mark J's 544, then having a flat cam and leaking rear main at 10,000 miles. Everyone else is in their 1800's on the East County tour, and your in a rice pick-up. Because your engine is apart in your garage. I should have paid more attention to these 'details' as I built it. The stock stuff just throws together and runs forever, why wouldn't this beafier aftermarket stuff be the same only stronger??

'Blueprinting'. I needed another .0005 to .001 clearance on those aftermarket lifters. Didn't know that. Didn't know the radii would be diff on the lifters and pushrods, heck the length was right! The lifters didn't spin, and my Swedeparts Kiloton II cam was toast in 10k miles. It was KILLER before it went out. I could beat a new BMW 325is until about 80 mph on El Camino Real in Carlsbad. we raced at least once/week. Would go 130 AT WILL! I don't blame the dual valve springs as mush as lifter clearance and pushrod radii, but even stock B20's take out cams by 80k miles. A lifter/pushrod engine is akin to Singer sewing machine treadell, anymore. The nice 2k engine, 1000 miles on it in my 544 was why I bought the car. I just thought it needed breaking in. The mechanic had the crank ground .010 undersize, 'blueprinted', but didn't carefully check the journals. The edges of the crank journals were not ground enough, interfered on cold mornings, seized, and ruined the WHOLE engine. Changes from stock need the utmost attention.

I hope you do it. Just want you to expect the worst, and work toward the best. IPD cams are conservative. Get one grade more radical than the catalog describes. A whole kit from them, properly installed checked etc. is your best bet. Get the valve springs, lifters, pushrods and a more radical cam than you are thinking, put in properly, have fun, make sure IPD will honor warrantee to fullest before spending money. Maybe you want to kick serious booty, and always have the rice truck for transpo’ just in case, put in speed parts! drive fast! If you do the assy’, pay Workman to check your parts first and work after. He knows. Crower has those blanks and will custom grind whatever you want, if you want to bargain build. (that's what I do)

Balancing is just adjusting the weight of all the parts, dynamically, so it will not vibrate as much. You can rev higher with a balanced engine, provided you get fuel in and exhaust out faster. This is best for any engine, and is in addition to 'blueprinting'.

Wow, print this and put in next newsletter.