L31 Vortec based engine build.
Pro
Joined: Jul 2021
Posts: 719
Likes: 156
What if ... the yet to be known piston sits 0.025" Below an OE deck ... and 0.015" Below your deck cut 0.010" ?
Nominal 0.040" Quench - 0.015" = 0.025" (gasket).
Seems 501 SD is about 0.0415" thick ... that would yield a large & ineffective quench of 0.0565" nearly 0.057"
If you desire a Composite gasket (like 501SD), suggest thinner (0.026") Mahle 5746:
Nominal 0.040" Quench - 0.015" = 0.025" (gasket). ... But with 0.026" gasket that would yield a decent quench of 0.041"
... or deck it 0.011" & yield 0.040" quench
... or deck it 0.012" & yield 0.039" quench etc etc
GM 10105117 is quite similar Composite but 0.028" thick and is OE on many performance motors.
* all the above based on a piston which sets 0.025" Below a stock, Uncut deck.
Nominal 0.040" Quench - 0.015" = 0.025" (gasket).
Seems 501 SD is about 0.0415" thick ... that would yield a large & ineffective quench of 0.0565" nearly 0.057"
If you desire a Composite gasket (like 501SD), suggest thinner (0.026") Mahle 5746:
Nominal 0.040" Quench - 0.015" = 0.025" (gasket). ... But with 0.026" gasket that would yield a decent quench of 0.041"
... or deck it 0.011" & yield 0.040" quench
... or deck it 0.012" & yield 0.039" quench etc etc
GM 10105117 is quite similar Composite but 0.028" thick and is OE on many performance motors.
* all the above based on a piston which sets 0.025" Below a stock, Uncut deck.
Safety Car
Joined: Jun 2017
Posts: 4,786
Likes: 425
From: North Georgia, USA
What if ... the yet to be known piston sits 0.025" Below an OE deck ... and 0.015" Below your deck cut 0.010" ?
Nominal 0.040" Quench - 0.015" = 0.025" (gasket).
Seems 501 SD is about 0.0415" thick ... that would yield a large & ineffective quench of 0.0565" nearly 0.057"
If you desire a Composite gasket (like 501SD), suggest thinner (0.026") Mahle 5746:
Nominal 0.040" Quench - 0.015" = 0.025" (gasket). ... But with 0.026" gasket that would yield a decent quench of 0.041"
... or deck it 0.011" & yield 0.040" quench
... or deck it 0.012" & yield 0.039" quench etc etc
GM 10105117 is quite similar Composite but 0.028" thick and is OE on many performance motors.
* all the above based on a piston which sets 0.025" Below a stock, Uncut deck.
Nominal 0.040" Quench - 0.015" = 0.025" (gasket).
Seems 501 SD is about 0.0415" thick ... that would yield a large & ineffective quench of 0.0565" nearly 0.057"
If you desire a Composite gasket (like 501SD), suggest thinner (0.026") Mahle 5746:
Nominal 0.040" Quench - 0.015" = 0.025" (gasket). ... But with 0.026" gasket that would yield a decent quench of 0.041"
... or deck it 0.011" & yield 0.040" quench
... or deck it 0.012" & yield 0.039" quench etc etc
GM 10105117 is quite similar Composite but 0.028" thick and is OE on many performance motors.
* all the above based on a piston which sets 0.025" Below a stock, Uncut deck.
I've found that most of the FelPro gaskets are almost like they're designed to get an engine back to stock compression, stock pushrod/rocker arm geometry and other stock specs after milling the heads and/or the block deck a total of 0.010" to 0.015". For someone doing repairs on a stock engine, that's often perfect because it "puts back" everything that was taken off in the machine shop. But when "designing" (or modifying) an engine for a specific purpose, with specific goals in mind, the FelPro gaskets aren't usually my first choice.
Pro
Joined: Jul 2021
Posts: 719
Likes: 156
fwiw, mahle 5746 (fka victor reinz, aka Napa, fka clevite)... used lotsa times in 10:1 CT race 350/355 ... CT stresses any motor ... 5746 holds up w/ no problem, no issue. Nice price too.
I like $80 gaskets; but if I know a $20 piece lives & works just as well, then I'll go with the bargain.
JMO. Only deck as much as is required to Primarily clean up decks, Secondarily achieve proper quench. If ya zero-deck a motor to begin with, you won't have anything left to cut if you damage a deck later on. Ideally, choice of piston and chamber volumes are for setting compression; not gasket. Plan & execute as a whole package. YMMV
I like $80 gaskets; but if I know a $20 piece lives & works just as well, then I'll go with the bargain.
JMO. Only deck as much as is required to Primarily clean up decks, Secondarily achieve proper quench. If ya zero-deck a motor to begin with, you won't have anything left to cut if you damage a deck later on. Ideally, choice of piston and chamber volumes are for setting compression; not gasket. Plan & execute as a whole package. YMMV
Thread Starter
Racer
Joined: Mar 2021
Posts: 278
Likes: 43
From: Kansas
What if ... the yet to be known piston sits 0.025" Below an OE deck ... and 0.015" Below your deck cut 0.010" ?
Nominal 0.040" Quench - 0.015" = 0.025" (gasket).
Seems 501 SD is about 0.0415" thick ... that would yield a large & ineffective quench of 0.0565" nearly 0.057"
If you desire a Composite gasket (like 501SD), suggest thinner (0.026") Mahle 5746:
Nominal 0.040" Quench - 0.015" = 0.025" (gasket). ... But with 0.026" gasket that would yield a decent quench of 0.041"
... or deck it 0.011" & yield 0.040" quench
... or deck it 0.012" & yield 0.039" quench etc etc
GM 10105117 is quite similar Composite but 0.028" thick and is OE on many performance motors.
* all the above based on a piston which sets 0.025" Below a stock, Uncut deck.
Nominal 0.040" Quench - 0.015" = 0.025" (gasket).
Seems 501 SD is about 0.0415" thick ... that would yield a large & ineffective quench of 0.0565" nearly 0.057"
If you desire a Composite gasket (like 501SD), suggest thinner (0.026") Mahle 5746:
Nominal 0.040" Quench - 0.015" = 0.025" (gasket). ... But with 0.026" gasket that would yield a decent quench of 0.041"
... or deck it 0.011" & yield 0.040" quench
... or deck it 0.012" & yield 0.039" quench etc etc
GM 10105117 is quite similar Composite but 0.028" thick and is OE on many performance motors.
* all the above based on a piston which sets 0.025" Below a stock, Uncut deck.
Still trying to figure out several things on pen and paper before pulling the trigger,
Pro
Joined: Jul 2021
Posts: 719
Likes: 156
Please don't sacrifice a good quench to solve V-P clearance. Chances are, the valve reliefs aka eyebrows alone will be sufficient. Yes or No, you'll verify w/ clay.
But, if not, adequate V-P clearance is routinely attained via machinist fly-cutting eyebrows a bit.
But, if not, adequate V-P clearance is routinely attained via machinist fly-cutting eyebrows a bit.
Thread Starter
Racer
Joined: Mar 2021
Posts: 278
Likes: 43
From: Kansas
I won't be sacrificing good quench. I am a couple months away from getting all my components at this point. Not buying a already balanced rotating assembly. Picking my parts individually and then going from there. Going with a Scat crank but not sure manufacturer on rods. We carry a lot of lines at work. So may go with someone else's rods.
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2nd Gear
Joined: Mar 2022
Posts: 2
Likes: 0
Following along...Any updates? Planning a similar build/rebuild myself but for my truck so have the complete L31 to start with. Although since it's been a slow stocking up of parts for a few months I won't be using much of the original engine lol but we'll see what happens when check out the rotating assembly 😅 but new top end is pretty much gathered up
Last edited by jjmccloud; Mar 21, 2022 at 10:21 AM.
Thread Starter
Racer
Joined: Mar 2021
Posts: 278
Likes: 43
From: Kansas
Following along...Any updates? Planning a similar build/rebuild myself but for my truck so have the complete L31 to start with. Although since it's been a slow stocking up of parts for a few months I won't be using much of the original engine lol but we'll see what happens when check out the rotating assembly 😅 but new top end is pretty much gathered up
2nd Gear
Joined: Mar 2022
Posts: 2
Likes: 0
I hear ya there, seems to be a chore half the time to get the parts you want. Its basically have alot of patience and qait on the things you really want or need, or settle for something else to get it done. Luckily for me it isn't a must have done thing this time so I can have a little patience lol still hard to so though. Keep us updated when you get everything going
Thread Starter
Racer
Joined: Mar 2021
Posts: 278
Likes: 43
From: Kansas
So I am undecided on the stroker and going 383 but am moving forward with 6" forged rods. I will either be using my stock L82 forged crank and sticking with a 355, or I will get a forged 3.75 stroke crank. Going with a 1pc rear main seal to 2pc adaptor. Either way I am staying with an internally balanced set up. This engine will be in my 1979 for a while and then get transplanted into my father's 1970 with a manual trans. My car will have the Th200r4. I will install a LS down the road.