odd combo and advice

[grumpyvette]

I was talking to a guy that owns a local shop a few years ago and some things he told just seem plain wrong. This guy has built some race winning engines and some of those were built dirt cheap like almost using other peoples throw away parts. I don't know if he's strait up lying or if he really practices what he preaches.

Some random things he told me.

Race engines do not use valve stem seals. What would the benefit if any be not to use them?

better valve guide lubrication at HIGHER RPMS, but keep in firmly in mind a RACE engine does NOT see intake plenum vacuum levels nearly as high as a lower rpm transportation engine sees,and they get rebuilt and use fresh spark plugs regularly, so you can get away with this

Race engines do not use gaskets. I have seen some of his work slathered in RTV looking stuff. I don't understand this theory and thinking this stuff used in massive quantity could get inside engine oil passages etc and cause oil flow problems or blockages.

in my opinion this is asking for trouble

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All the engines I have seen this guy produce seem to follow a set of rules that seem 180* of what you would expect. Like rather than building a race engine for top end power he builds these low RPM torque monsters that actually do win races.

maximizing the useful torque curve with the correct gearing can produce surprisingly efficient power curves, , it makes a great deal more sense to build an engine that has a useful torque curve over lets say 3500rpm vs a bit higher peak power over a far narrower lets say 1200rpm PROVIDED the gearing is correctly matched and the peak power is fairly close
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I saw him build a sprint car engine that ran like a diesel. compared to the other cars on the track it was grumbling along at a low rpm while all the other cars were turning some serious revs this was in a car driven by a friend of mine. once again he was winning races.

Ive built several engines that were used in stock car racing and many guys over cam the engines and are limited by the rules to restrictive flow cylinder heads or intakes that won,t allow the engine to breath where the cams designed to maximize power in the rpm band

Another thing this guy is good at is using factory cast iron heads. He has the machines to rebuild these heads so I guess its just time involved rather than money thrown away at a machine shop. He was telling me that 2.02 / 1.60 valves flow less than a set of 1.94/1.50 with all the work he does to them. Seems to me that a if he did the same work to a bigger valve it would flow the best.

pure physics will tell you a larger valve curtain are can potentially flow more air, but many stock car rules LIMIT the potential parts that you can use and if the intake and heads and cam are carefully matched a slightly smaller valve may handle all the air flow available, a larger valve may not be useful in some restricted combos

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I don't know this guy says and does some really different things that in my book is questionable but yet he produces some strong engines that are like below claimer class stuff. From what I have been told he did some work for Mercedes factory engineering.

 

[grumpyvette]

I think that like many guys who were interested in faster cars ,I was like most of you and many of us learned a great deal from older more experienced friends, and we learned a great deal by watching but even more by helping and doing our own work,on our own cars!
I well remember helping on my first valve job, clutch replacement and cam swap, and now look back and shudder, just thinking of the near endless list of mistakes we made thru pure ignorance. :roll: theres no question that an older well establish machine shop can get you good prices and provide very helpful guidance at times, the problem is that many machine shops, are owned and run by guys who are more interested in making the most potential profits for the least possible work, rather than helping to build the best possible engine for the lowest cost!
finding a honest reliable,and dependable, machine shop willing to guide and teach you, and do the work at reasonable prices in a reasonably quick time frame, is from what Ive seen a rare commodity lately, finding one that does top quality work and completes it on the date and at the price you agreed too even rarer!
SOME of the The Older machine shops, both, knew how to build durable engines that made impressive power and were willing to help educate you on why things should be done a certain way when there were few or no off the shelf aftermarket parts, and thinking thru what you were doing and what needed to be modified to help increase power or durability was key to success.

when I was 19-20 years old, we thought nothing about clearances , , most of us tended to read thru magazine articles and assume they were telling you everything you needed to know ,so you could duplicate thier results, if we saw a Z28 off road cam,that made 45 extra HP , well it was designed to fit a SBC engine! we bought it along with a new set of lifters and just swapped it in, figuring it was instantly worth the listed 45hp the fact that the stock valve train was still installed or the cars compression ratio or rear gearing was a total mis-match and the heads they used were extensively ported (that was never mentioned in the article of course)never dawned on us back then!
factors like
spring bind?
proper clearances?
bearing crush?
bore surface?
hone plates?
multi angle valve jobs?
ring end gaps?
port flow rates?
plenum and runner design?
header design and exhaust back pressure!
at that point that was mostly a totally unknown list of concepts, but thru expensive trial and error we learned WHY and HOW things worked
(and what USUALLY caused EXPENSIVE REBUILDS)
the formula for hp is (tq x rpm/5252=hp
example
450 ft lbs of torque at 3000rpm=257hp
450 ft lbs of torque at 6000rpm=514hp
because the torque is available at that higher RPM RATE and at the higher rpm using gearing the rotational force the engine supplied can be applied faster or slower to the rear tires
heres some useful related info,
that taking the effort of reading thru,
may help prevent you from going thru the same expensive learning curve!

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