BBC mild build valve size

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Mark Williams
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BBC mild build valve size

Post by Mark Williams »

Mild hyd roller combo
454 .030 over 2 bolt.
Cast Ohio crankshaft, 7/16” rods, speed pro 2399 pistons, scat sfi flexplate, pioneer 872006 damper, ARP bolts for damper and flex plate all balanced(yes it needed mallory).

Zz502 Camshaft 224/234 .527/.544(.558/.576 with 1.8 ratio)110 ls, Comp cams 15854-16 lifter, Comp hi tech 3/8”, Comp cams 1.8-1 stainless steel full roller rocker arms 1128-16, Rocker arms studs from my Brodix BB2 heads (that needed longer studs) and 3/8” oem guide plates.

#241 -71 oval port heads with Pac 1916 hot rod spring set up @ 140 seat/390 open.
Heads will get new k-lines, cut for positive seals, flat milled, and a multi angle valve job.

Edelbrock RPM air gap intake, Holley 3310(modified to 4150).

MSD pro billet distributor with a HEI module and a Fast ps60 ignition coil, Taylor 51063 spark plug wires, gmpp wire looms.

Skip white chrome swp mech waterpump, aftermarket alu Water pump pulleys.

So big question is use the new 2.0625/1.72 oem size Elgin stainless steel valves I have or will I leave lots of power on the table not step up to 2.19/1.72 valves? If I step up in size heads will have no porting just little blending so its a smoth transition. My headbuilder doesnt port and porting is out of budget.

Are we talking 10-15 hp going up in valve size or will I benefit more power going up in size even with no porting? Since I already has the oem sizes valves I was set on use them but started thinking if its worth stepping up, price for machine work is same just the extra money for the valves.
So is it worth spending 150-200$ extra for valves on usch a mild build that probably never will see the track if I will gain 10-15 hp itsnot worth it imho?

Engine is probably done 5600 anyway.

Hoping it will make 450 hp and it will be put in a cruiser, 64 Chevelle 3500 lbs, th 400 with 2500 in stall, 3.31 rear gears.
user-30257

Re: BBC mild build valve size

Post by user-30257 »

Use the valves you have. That's enough valve for more hp than you will make.
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Re: BBC mild build valve size

Post by GRTfast »

Mark Williams wrote: Thu Mar 22, 2018 7:21 am Mild hyd roller combo
454 .030 over 2 bolt.
Cast Ohio crankshaft, 7/16” rods, speed pro 2399 pistons, scat sfi flexplate, pioneer 872006 damper, ARP bolts for damper and flex plate all balanced(yes it needed mallory).

Zz502 Camshaft 224/234 .527/.544(.558/.576 with 1.8 ratio)110 ls, Comp cams 15854-16 lifter, Comp hi tech 3/8”, Comp cams 1.8-1 stainless steel full roller rocker arms 1128-16, Rocker arms studs from my Brodix BB2 heads (that needed longer studs) and 3/8” oem guide plates.

#241 -71 oval port heads with Pac 1916 hot rod spring set up @ 140 seat/390 open.
Heads will get new k-lines, cut for positive seals, flat milled, and a multi angle valve job.

Edelbrock RPM air gap intake, Holley 3310(modified to 4150).

MSD pro billet distributor with a HEI module and a Fast ps60 ignition coil, Taylor 51063 spark plug wires, gmpp wire looms.

Skip white chrome swp mech waterpump, aftermarket alu Water pump pulleys.

So big question is use the new 2.0625/1.72 oem size Elgin stainless steel valves I have or will I leave lots of power on the table not step up to 2.19/1.72 valves? If I step up in size heads will have no porting just little blending so its a smoth transition. My headbuilder doesnt port and porting is out of budget.

Are we talking 10-15 hp going up in valve size or will I benefit more power going up in size even with no porting? Since I already has the oem sizes valves I was set on use them but started thinking if its worth stepping up, price for machine work is same just the extra money for the valves.
So is it worth spending 150-200$ extra for valves on usch a mild build that probably never will see the track if I will gain 10-15 hp itsnot worth it imho?

Engine is probably done 5600 anyway.

Hoping it will make 450 hp and it will be put in a cruiser, 64 Chevelle 3500 lbs, th 400 with 2500 in stall, 3.31 rear gears.
How much compression? I have a similar build, but my cam is a comp cams "thumpr", compression is 9.5:1, and I have Brodix race rite bb2's.

mine made 494 hp and 532 ft*lbs on the dyno after break in. I'd say 450hp is easily achievable with your setup. Wouldn't be surprised if you made more.
Take the risk of thinking for yourself, much more happiness, truth, beauty, and wisdom will come to you that way. -Hitchens
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Re: BBC mild build valve size

Post by mag2555 »

With that much lift the stock 2,06" heads should be flowing close to 240 cfm@28" which should make you 450 hp easy!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: BBC mild build valve size

Post by Mark Williams »

GRTfast wrote: Thu Mar 22, 2018 7:34 am
Mark Williams wrote: Thu Mar 22, 2018 7:21 am Mild hyd roller combo
454 .030 over 2 bolt.
Cast Ohio crankshaft, 7/16” rods, speed pro 2399 pistons, scat sfi flexplate, pioneer 872006 damper, ARP bolts for damper and flex plate all balanced(yes it needed mallory).

Zz502 Camshaft 224/234 .527/.544(.558/.576 with 1.8 ratio)110 ls, Comp cams 15854-16 lifter, Comp hi tech 3/8”, Comp cams 1.8-1 stainless steel full roller rocker arms 1128-16, Rocker arms studs from my Brodix BB2 heads (that needed longer studs) and 3/8” oem guide plates.

#241 -71 oval port heads with Pac 1916 hot rod spring set up @ 140 seat/390 open.
Heads will get new k-lines, cut for positive seals, flat milled, and a multi angle valve job.

Edelbrock RPM air gap intake, Holley 3310(modified to 4150).

MSD pro billet distributor with a HEI module and a Fast ps60 ignition coil, Taylor 51063 spark plug wires, gmpp wire looms.

Skip white chrome swp mech waterpump, aftermarket alu Water pump pulleys.

So big question is use the new 2.0625/1.72 oem size Elgin stainless steel valves I have or will I leave lots of power on the table not step up to 2.19/1.72 valves? If I step up in size heads will have no porting just little blending so its a smoth transition. My headbuilder doesnt port and porting is out of budget.

Are we talking 10-15 hp going up in valve size or will I benefit more power going up in size even with no porting? Since I already has the oem sizes valves I was set on use them but started thinking if its worth stepping up, price for machine work is same just the extra money for the valves.
So is it worth spending 150-200$ extra for valves on usch a mild build that probably never will see the track if I will gain 10-15 hp itsnot worth it imho?

Engine is probably done 5600 anyway.

Hoping it will make 450 hp and it will be put in a cruiser, 64 Chevelle 3500 lbs, th 400 with 2500 in stall, 3.31 rear gears.
How much compression? I have a similar build, but my cam is a comp cams "thumpr", compression is 9.5:1, and I have Brodix race rite bb2's.

mine made 494 hp and 532 ft*lbs on the dyno after break in. I'd say 450hp is easily achievable with your setup. Wouldn't be surprised if you made more.
Thanks! What spec on the thumpr?

I will cc the Chambers once heads are done but guess close to 9.5:1 in compression.
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Re: BBC mild build valve size

Post by Mark Williams »

Headguy wrote: Thu Mar 22, 2018 7:25 am Use the valves you have. That's enough valve for more hp than you will make.

Thanks! What I thought but got unsure.
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Re: BBC mild build valve size

Post by Mark Williams »

mag2555 wrote: Thu Mar 22, 2018 7:42 am With that much lift the stock 2,06" heads should be flowing close to 240 cfm@28" which should make you 450 hp easy!
I sure hope so the zz502 is listed as 502 hp or 508 hp but it has gmpp/edelbrock heads same compression as I will end up with, I have 40 cui less and only + I have is the extra lift from the 1.8 rockers as a + but you might be correct?
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Re: BBC mild build valve size

Post by GRTfast »

Mark Williams wrote: Thu Mar 22, 2018 7:51 am
GRTfast wrote: Thu Mar 22, 2018 7:34 am
Mark Williams wrote: Thu Mar 22, 2018 7:21 am Mild hyd roller combo
454 .030 over 2 bolt.
Cast Ohio crankshaft, 7/16” rods, speed pro 2399 pistons, scat sfi flexplate, pioneer 872006 damper, ARP bolts for damper and flex plate all balanced(yes it needed mallory).

Zz502 Camshaft 224/234 .527/.544(.558/.576 with 1.8 ratio)110 ls, Comp cams 15854-16 lifter, Comp hi tech 3/8”, Comp cams 1.8-1 stainless steel full roller rocker arms 1128-16, Rocker arms studs from my Brodix BB2 heads (that needed longer studs) and 3/8” oem guide plates.

#241 -71 oval port heads with Pac 1916 hot rod spring set up @ 140 seat/390 open.
Heads will get new k-lines, cut for positive seals, flat milled, and a multi angle valve job.

Edelbrock RPM air gap intake, Holley 3310(modified to 4150).

MSD pro billet distributor with a HEI module and a Fast ps60 ignition coil, Taylor 51063 spark plug wires, gmpp wire looms.

Skip white chrome swp mech waterpump, aftermarket alu Water pump pulleys.

So big question is use the new 2.0625/1.72 oem size Elgin stainless steel valves I have or will I leave lots of power on the table not step up to 2.19/1.72 valves? If I step up in size heads will have no porting just little blending so its a smoth transition. My headbuilder doesnt port and porting is out of budget.

Are we talking 10-15 hp going up in valve size or will I benefit more power going up in size even with no porting? Since I already has the oem sizes valves I was set on use them but started thinking if its worth stepping up, price for machine work is same just the extra money for the valves.
So is it worth spending 150-200$ extra for valves on usch a mild build that probably never will see the track if I will gain 10-15 hp itsnot worth it imho?

Engine is probably done 5600 anyway.

Hoping it will make 450 hp and it will be put in a cruiser, 64 Chevelle 3500 lbs, th 400 with 2500 in stall, 3.31 rear gears.
How much compression? I have a similar build, but my cam is a comp cams "thumpr", compression is 9.5:1, and I have Brodix race rite bb2's.

mine made 494 hp and 532 ft*lbs on the dyno after break in. I'd say 450hp is easily achievable with your setup. Wouldn't be surprised if you made more.
Thanks! What spec on the thumpr?

I will cc the Chambers once heads are done but guess close to 9.5:1 in compression.

http://www.compcams.com/Company/CC/cam- ... d=485&sb=2
Take the risk of thinking for yourself, much more happiness, truth, beauty, and wisdom will come to you that way. -Hitchens
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Re: BBC mild build valve size

Post by Frankshaft »

The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
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Re: BBC mild build valve size

Post by Mark Williams »

GRTfast wrote: Thu Mar 22, 2018 8:31 am
Mark Williams wrote: Thu Mar 22, 2018 7:51 am
GRTfast wrote: Thu Mar 22, 2018 7:34 am

How much compression? I have a similar build, but my cam is a comp cams "thumpr", compression is 9.5:1, and I have Brodix race rite bb2's.

mine made 494 hp and 532 ft*lbs on the dyno after break in. I'd say 450hp is easily achievable with your setup. Wouldn't be surprised if you made more.
Thanks! What spec on the thumpr?

I will cc the Chambers once heads are done but guess close to 9.5:1 in compression.

http://www.compcams.com/Company/CC/cam- ... d=485&sb=2
:thumbsup: it has little more duration but less lift I sure would be trilled if my combo puts out more than 450 hp, how does it sound?
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Re: BBC mild build valve size

Post by statsystems »

Frankshaft wrote: Thu Mar 22, 2018 10:09 am The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
^^^^^^^^^^^^^^^^^^^^^THIS^^^^^^^^^^^

You will never even get a respectable valve job with a stock diameter valve.
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Re: BBC mild build valve size

Post by GRTfast »

Mark Williams wrote: Thu Mar 22, 2018 10:11 am
GRTfast wrote: Thu Mar 22, 2018 8:31 am
Mark Williams wrote: Thu Mar 22, 2018 7:51 am

Thanks! What spec on the thumpr?

I will cc the Chambers once heads are done but guess close to 9.5:1 in compression.

http://www.compcams.com/Company/CC/cam- ... d=485&sb=2
:thumbsup: it has little more duration but less lift I sure would be trilled if my combo puts out more than 450 hp, how does it sound?
Nice choppy idle around 800 rpm. Cleans up around 1500 rpm. Pulls hard to 6000rpm.
Take the risk of thinking for yourself, much more happiness, truth, beauty, and wisdom will come to you that way. -Hitchens
Mark Williams
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Re: BBC mild build valve size

Post by Mark Williams »

Frankshaft wrote: Thu Mar 22, 2018 10:09 am The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
Special valves is out question IF I will buy another set of elgins 2.19/1.88

So how much power are Im leaving on the table?

Is it worth it on such a mild build that is from parts I had laying around collecting dust just wanted to make some fun out of it and possible sell or use as a cruiser/spare engine I have a 496 with brodix heads etc 600+hp
statsystems wrote: Thu Mar 22, 2018 10:45 am
Frankshaft wrote: Thu Mar 22, 2018 10:09 am The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
^^^^^^^^^^^^^^^^^^^^^THIS^^^^^^^^^^^

You will never even get a respectable valve job with a stock diameter valve.
But with a stock exhaust valve I will get a respectable valve job? or isnt it as importent as intakes? Will it be good enough for a spare engine out of parts I had on the shelf, trying to build something without spending big $

Headguy should try to cut tomorrow and see he was optimistic?
user-30257

Re: BBC mild build valve size

Post by user-30257 »

Mark Williams wrote: Thu Mar 22, 2018 11:18 am
Frankshaft wrote: Thu Mar 22, 2018 10:09 am The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
Special valves is out question IF I will buy another set of elgins 2.19/1.88

So how much power are Im leaving on the table?

Is it worth it on such a mild build that is from parts I had laying around collecting dust just wanted to make some fun out of it and possible sell or use as a cruiser/spare engine I have a 496 with brodix heads etc 600+hp
statsystems wrote: Thu Mar 22, 2018 10:45 am
Frankshaft wrote: Thu Mar 22, 2018 10:09 am The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
^^^^^^^^^^^^^^^^^^^^^THIS^^^^^^^^^^^

You will never even get a respectable valve job with a stock diameter valve.
But with a stock exhaust valve I will get a respectable valve job? or isnt it as importent as intakes? Will it be good enough for a spare engine out of parts I had on the shelf, trying to build something without spending big $

Headguy should try to cut tomorrow and see he was optimistic?
Valve size isn't the restriction I can assure you. The power you are leaving in the table would be from your cam choice . I agree with Frankshaft.

But you have the right stuff to make the power you want.
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Re: BBC mild build valve size

Post by Mark Williams »

Headguy wrote: Thu Mar 22, 2018 11:45 am
Mark Williams wrote: Thu Mar 22, 2018 11:18 am
Frankshaft wrote: Thu Mar 22, 2018 10:09 am The advantage going to a bigger intake valve on those heads is you can actually have a "valve job". Instead of a top cut, seat and a gaping 75 degree bowl hog right to the intake seat. Call Rev, they have or will make you a 2.125 intake valve that fits the stock bowl perfect. The throat % will be right on, you will have all the angles, and you can blend the ridge off and its like they are properly "bowl" ported. Stay with the 1.725 exhaust valves. Another low cost alternative is a ferrea 5000 series intake valve for a Pontiac edelbrock performer rpm head. Its like 5.25 long, and is 2.11 od. The only thing, is its a 11/32 stem, which is good. Have the head guy put in 11/32 guides on the intake. It will allow you to accomplish the same as above. It works good.
Special valves is out question IF I will buy another set of elgins 2.19/1.88

So how much power are Im leaving on the table?

Is it worth it on such a mild build that is from parts I had laying around collecting dust just wanted to make some fun out of it and possible sell or use as a cruiser/spare engine I have a 496 with brodix heads etc 600+hp
statsystems wrote: Thu Mar 22, 2018 10:45 am

^^^^^^^^^^^^^^^^^^^^^THIS^^^^^^^^^^^

You will never even get a respectable valve job with a stock diameter valve.
But with a stock exhaust valve I will get a respectable valve job? or isnt it as importent as intakes? Will it be good enough for a spare engine out of parts I had on the shelf, trying to build something without spending big $

Headguy should try to cut tomorrow and see he was optimistic?
Valve size isn't the restriction I can assure you. The power you are leaving in the table would be from your cam choice . I agree with Frankshaft.

But you have the right stuff to make the power you want.
Thanks! Yes know I could have more power but limited it on purpose to around 450hp since it will be a cruiser only have my 489 for drag strip and if I want more power.

The thought was to use what I had and make "decent" power for the money spent and have a nice spare engine or a engine to sell with a small profit.

So if my head guy can cut the heads for oem size valves(he use a mira multi angle cutter) I will stay with them and not save some money.
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