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383 sbc build

General engine tech -- Drag Racing to Circle Track

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fastblackracing
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383 sbc build

Post by fastblackracing » Fri Feb 08, 2019 8:07 pm

I am trying to talk a friend of mine at work into letting me build him a nice 475-500hp
383 for his el-camino and while I have a few older 4 bolt 2 piece rear main seal blocks
I would like to build a 1 piece seal block but I do not know what year block to look for?

What else needs to be considered if going to a 1 piece block? Thanks for the help.

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Re: 383 sbc build

Post by BILL-C » Fri Feb 08, 2019 8:33 pm

Only some of the 1 piece rear main seal blocks have provision for a mechanical fuel pump.
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fastblackracing
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Re: 383 sbc build

Post by fastblackracing » Fri Feb 08, 2019 8:36 pm

BILL-C wrote:
Fri Feb 08, 2019 8:33 pm
Only some of the 1 piece rear main seal blocks have provision for a mechanical fuel pump.
Thanks for the heads up, this is a good point I need to know.

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Re: 383 sbc build

Post by PackardV8 » Fri Feb 08, 2019 9:00 pm

fastblackracing wrote:
Fri Feb 08, 2019 8:07 pm
I am trying to talk a friend of mine at work into letting me build him a nice 475-500hp
383
Only some of the 1 piece rear main seal blocks have provision for a mechanical fuel pump.
But then, who's building a 500hp Elco with a mechanical pump? Wouldn't one begin with an electric pump back by the tank to insure the supply?

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Re: 383 sbc build

Post by cgarb » Fri Feb 08, 2019 10:30 pm

I have a 650hp 421 SBC with a mechanical fuel pump. Plenty of fuel and simple. It's not a stock pump and the lines are #10 an feed to the pump to keep up the volume.

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Re: 383 sbc build

Post by steve cowan » Sat Feb 09, 2019 4:04 am

fastblackracing wrote:
Fri Feb 08, 2019 8:07 pm
I am trying to talk a friend of mine at work into letting me build him a nice 475-500hp
383 for his el-camino and while I have a few older 4 bolt 2 piece rear main seal blocks
I would like to build a 1 piece seal block but I do not know what year block to look for?

What else needs to be considered if going to a 1 piece block? Thanks for the help.
it has been mentioned a couple of times over the years-
with a 3.75'' stroke the oil ring can be exposed at the bottom of the bore at BDC.
i have been using a holley 200gph mechanical fuelpump for a few years on my old 010 4 bolt blocks,the howards composite fuel pump pushrod is only just starting to show signs of wear.
steve c

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Re: 383 sbc build

Post by BLOCKMAN » Sat Feb 09, 2019 9:31 am

steve cowan wrote:
Sat Feb 09, 2019 4:04 am
fastblackracing wrote:
Fri Feb 08, 2019 8:07 pm
I am trying to talk a friend of mine at work into letting me build him a nice 475-500hp
383 for his el-camino and while I have a few older 4 bolt 2 piece rear main seal blocks
I would like to build a 1 piece seal block but I do not know what year block to look for?

What else needs to be considered if going to a 1 piece block? Thanks for the help.
it has been mentioned a couple of times over the years-
with a 3.75'' stroke the oil ring can be exposed at the bottom of the bore at BDC.
i have been using a holley 200gph mechanical fuelpump for a few years on my old 010 4 bolt blocks,the howards composite fuel pump pushrod is only just starting to show signs of wear.
I would use 6.0 or 6.125 rods and a Mahle piston so far zero problems, They use a 1MM 1MM 2MM ring pack.

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Re: 383 sbc build

Post by Newold1 » Sat Feb 09, 2019 10:55 am

Select a nice 2 piece main seal block you have. Mag it, check the main bore and align hone as needed. Square the deck and bore it with deck plate, hone and plateau hone for your ring type. Use a good quality rear main seal and offset the gaps on the two piece seal. If the budget allows use an ARP main bolt kit
This is as good as it should get.

2 piece seals only tend to leak when the crank seal surfaces are not proper and the seal is cheap and improperly installed.
The Older I Get, The Dumber I Get :wink:

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Re: 383 sbc build

Post by BLOCKMAN » Sat Feb 09, 2019 11:12 am

Newold1 wrote:
Sat Feb 09, 2019 10:55 am
Select a nice 2 piece main seal block you have. Mag it, check the main bore and align hone as needed. Square the deck and bore it with deck plate, hone and plateau hone for your ring type. Use a good quality rear main seal and offset the gaps on the two piece seal. If the budget allows use an ARP main bolt kit
This is as good as it should get.

2 piece seals only tend to leak when the crank seal surfaces are not proper and the seal is cheap and improperly installed.

Forgot the sonic test. I had 4 blocks fail this week

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Re: 383 sbc build

Post by PackardV8 » Sat Feb 09, 2019 11:47 am

BLOCKMAN wrote:
Sat Feb 09, 2019 11:12 am
Forgot the sonic test. I had 4 blocks fail this week.
For future reference, at what locations and at what bore diameters are your SBC blocks most commonly lacking?

Only slightly OT, but has everyone else noticed it's almost impossible to sell a customer on a 2-bolt build? This is not 500hp; these are guys building a stock or mild street engine to go in an older pickup. "Nope, gotta have that 4-bolt main block."

When asked, "Did you have any problems the first 150,000 miles with the original 2-bolt block?"

"Nawbutt my buddies say go with the 4-bolt cause I might wanna tow with it."

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Re: 383 sbc build

Post by BLOCKMAN » Sat Feb 09, 2019 12:24 pm

PackardV8 wrote:
Sat Feb 09, 2019 11:47 am
BLOCKMAN wrote:
Sat Feb 09, 2019 11:12 am
Forgot the sonic test. I had 4 blocks fail this week.
For future reference, at what locations and at what bore diameters are your SBC blocks most commonly lacking?

Only slightly OT, but has everyone else noticed it's almost impossible to sell a customer on a 2-bolt build? This is not 500hp; these are guys building a stock or mild street engine to go in an older pickup. "Nope, gotta have that 4-bolt main block."

When asked, "Did you have any problems the first 150,000 miles with the original 2-bolt block?"

"Nawbutt my buddies say go with the 4-bolt cause I might wanna tow with it."

jack vines
GM blocks have a lot of issues when it comes to uniform cylinders, Most blocks I see its one cylinder that fails the whole block. There is no specific location in the cylinder that is bad, It could at the bottom or top wrist pin side. GM's casting process seems pretty crude when you sonic test a block.

2 Bolt for a 3.750 stroke I will not do. Look at GM with the 2 bolt 400 block they had that figured out the 2 bolt center caps are the same width as the 4 bolt cap. The longer cap does side load the main caps more.

I have seen 2 barrel circle track engines 370 horse move two bolt caps in the register probably due to 6800 RPM lap after lap.

I am not basing my info on just one build but many years of engine building and machining. I have seen quite a few broken 2 bolt caps over the years.

Its always been a good debate to say the least, I just say roll the dice with a two bolt. I do convert quite a few 2 bolt blocks to splayed caps and those are great choice over the standard 4 bolt caps as they tie the pan rain into the area of stress.

Good luck which ever way you go.

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Re: 383 sbc build

Post by travis » Sat Feb 09, 2019 4:01 pm

PackardV8 wrote:
Sat Feb 09, 2019 11:47 am
BLOCKMAN wrote:
Sat Feb 09, 2019 11:12 am
Forgot the sonic test. I had 4 blocks fail this week.
For future reference, at what locations and at what bore diameters are your SBC blocks most commonly lacking?

Only slightly OT, but has everyone else noticed it's almost impossible to sell a customer on a 2-bolt build? This is not 500hp; these are guys building a stock or mild street engine to go in an older pickup. "Nope, gotta have that 4-bolt main block."

When asked, "Did you have any problems the first 150,000 miles with the original 2-bolt block?"

"Nawbutt my buddies say go with the 4-bolt cause I might wanna tow with it."

jack vines
And that is why I used to get 2 bolt 350’s for free or dirt cheap 😂

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Re: 383 sbc build

Post by BLOCKMAN » Sat Feb 09, 2019 5:22 pm

travis wrote:
Sat Feb 09, 2019 4:01 pm
PackardV8 wrote:
Sat Feb 09, 2019 11:47 am
BLOCKMAN wrote:
Sat Feb 09, 2019 11:12 am
Forgot the sonic test. I had 4 blocks fail this week.
For future reference, at what locations and at what bore diameters are your SBC blocks most commonly lacking?

Only slightly OT, but has everyone else noticed it's almost impossible to sell a customer on a 2-bolt build? This is not 500hp; these are guys building a stock or mild street engine to go in an older pickup. "Nope, gotta have that 4-bolt main block."

When asked, "Did you have any problems the first 150,000 miles with the original 2-bolt block?"

"Nawbutt my buddies say go with the 4-bolt cause I might wanna tow with it."

jack vines
And that is why I used to get 2 bolt 350’s for free or dirt cheap 😂
Same here and thats why I put splayed caps on those blocks. :lol:

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Re: 383 sbc build

Post by Dave Koehler » Sat Feb 09, 2019 7:46 pm

On one hand that story proves reality is funny but so it the idea of a 150K mile SB from the 70s
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Re: 383 sbc build

Post by travis » Sat Feb 09, 2019 9:29 pm

Dave Koehler wrote:
Sat Feb 09, 2019 7:46 pm
On one hand that story proves reality is funny but so it the idea of a 150K mile SB from the 70s
At 150k most were mosquitoe foggers :lol:

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