3 rings per piston means rough sealing surface used?
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3 rings per piston means rough sealing surface used?
2 compression rings and 1 oil scraper is pretty typical for a 4-stroke.
NR500 .. they named that one right … still "Not Ready" after 30+ years … :o
https://www.screamandfly.com/attachm...2&d=1593838824
https://www.screamandfly.com/images/misc/quote_icon.png Originally Posted by Capt.Insane-o https://www.screamandfly.com/images/...post-right.png
My father was an apprentice at Grey Iron when the 396 was being developed as a "marine motor" sh*t in the valve train doesn't even point in the right direction, how that pile of junk became ballyhoooed as one of the greatest motors of all time is way beyond me.
Fugimotosan says :
...so true. as you know, they morphed into the 427, 454, & so on, over the years. you would have thought GM could have fixed all those decades of bad valvetrain production. nope! as they came from GM, a large percentage failed. particularly the ones that were marinized by marine engine suppliers in stock form. it was up to the customer to spend the bigger dollars to upgrade with an aftermarket valvetrain. ridiculous. sustained 5,000 rpm? hell no.
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The simple answer is :
If they put the valves inline .. it would just be another small port, small valve motor that runs 1/3rd of the valve up against the chamber and cylinder wall... you know, like a .. 383 / 440 NoPar .. :D
Common sense dictates :
Going with the "Porcupine" head , the valve moves away from the wall as it opens and closes . Splaying the valves also allows the ports to be much bigger with a better line of sight entry .. ;)
She's so fine, my 409 :
The valve angle , rocker arm and push rod all run on the same plane . The only change of direction is at the lifter / pushrod junction . The only people I know that had problems had the wrong length pushrods in place or had sacked out valve springs . The rocker needs to seat on the outer 1/3 rd of the valve stem . Then sweeping to the inner 1/3rd at full lift , then back again as it closes .
Pre Limiter :
Being that they would rev freely from the airflow capacity .. it's easy to over rev the motor and hurt parts . Not the motors fault … is it .. :cool:
I've had short stroke Big blocks that would go 9000 .. and hurt nothing .. :smiletest:
The 500" Pro / Stock guys run them up in the 11,000 rpm range ..pass after pass ;)
It's not 1965 anymore …. :D
They are popular because :
They came with steel cranks from the factory. 4 bolt blocks. 6 bolt heads. 4.840 bore space . Rocker pedestals are also 4.840 apart .. simple . The same basic 396 platform goes to 632 cubic inch's . And up to 1000 + ci in todays world of CNC machining . Did I mention airflow … :cheers:
Chaz= thinkin, Dick Keinath has passed on , but his design will live on way past any of us …
http://st.hotrod.com/uploads/sites/2...singray-13.jpg
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Same thing works for the canted valve Ford Cleveland small block.
I almost posted something about seeing the Gapp + Roush "Tijuana Taxi" run at Miami~Hollywood and Gainesville … :thumbsup:Quote:
Originally Posted by Da Bull
https://2.bp.blogspot.com/-n2s2x2H51...640/taxi_1.jpg
Smokey told Chevrolet in the early 1950's that the "new" smallblock head was too short to get the ports up high enough to get the short turn radius big enough to , make the turn , straighten the flow .. and use the whole valves circumference . They didn't listen to him , but Richard Maskins sure did .. :smiletest:
http://www.besracing.com/images/mana...E-HEAD-004.jpg
https://tse3.mm.bing.net/th?id=OIP.0...=0&w=272&h=182
Get away from that wall … :D
https://i0.wp.com/hotrodenginetech.c...chief-3_lg.jpg
CNC done.Quote:
Originally Posted by Da Bull
Watched this a while ago...he is a modest genius.
https://www.youtube.com/watch?v=AV1vb9MZnrI
...very familiar & a great design. and in stock factory form, had no rocker/valvetrain issues like the bbc.Quote:
Originally Posted by Da Bull
...again, very familiar with the porcupine/canted valve design chaz. i was in warranty for decades with these engines in ''stock" factory versions. too many warranty replacement units to count. i have hi-performance bbc experience as well, which is not what i was referencing.Quote:
Originally Posted by Chaz
Never got into big blocks even though they made them in my town of Tonawanda I believe it was called the Mark IV line, 50 years... no more.
I had a 64 Vette 327 with a few extra parts that would beat any big block around If I raced from a press, about died in it racing a new 440 Cuda this was 1971, going over a R/R crossing, while driving me to the Hospital the 440 6 pack Cuda owner could not believe he was getting beat by a 327, power to weight ratio and a motor that could breath real well.
Small blocks sing high notes:D
j
I had a 64 Vette 327 with a few extra parts that would beat any big block around If I raced from a press, about died in it racing a new 440 Cuda this was 1971, going over a R/R crossing, while driving me to the Hospital the 440 6 pack Cuda owner could not believe he was getting beat by a 327, power to weight ratio and a motor that could breath real well.
Ok, who won, you or the Cuda??? And if you are a Chevy guy, why are you called Cuda???
j[/QUOTE]
back in the late sixties/early seventies, the factory big block cars(no matter which one you choose of the big three) could not get any traction. for acceleration OR handling. those goodyear polyglas gt's didn't stand a chance, lol. or the firestone wide-ovals. they just sat there and sizzled.:smiletest: