383 sbc build

General engine tech -- Drag Racing to Circle Track

Moderator: Team

fastblackracing
Member
Member
Posts: 118
Joined: Sun Feb 15, 2015 12:13 am
Location:

383 sbc build

Post by fastblackracing »

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.
BILL-C
Expert
Expert
Posts: 746
Joined: Thu Feb 07, 2008 9:57 pm
Location: Oakville, CT
Contact:

Re: 383 sbc build

Post by BILL-C »

Only some of the 1 piece rear main seal blocks have provision for a mechanical fuel pump.
Carlquist Competition Engines
fastblackracing
Member
Member
Posts: 118
Joined: Sun Feb 15, 2015 12:13 am
Location:

Re: 383 sbc build

Post by fastblackracing »

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.
PackardV8
Guru
Guru
Posts: 7619
Joined: Sun Jul 30, 2006 2:03 pm
Location: Spokane, WA

Re: 383 sbc build

Post by PackardV8 »

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?

jack vines
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
cgarb
Guru
Guru
Posts: 2006
Joined: Wed Jul 09, 2014 11:50 am
Location: Maryland

Re: 383 sbc build

Post by cgarb »

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.
steve cowan
Guru
Guru
Posts: 2253
Joined: Wed Jul 27, 2011 5:22 am
Location: brisbane AUSTRALIA

Re: 383 sbc build

Post by steve cowan »

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
"Pretty don't make power"
Newold1
Guru
Guru
Posts: 1963
Joined: Fri Apr 08, 2016 9:50 am
Location:

Re: 383 sbc build

Post by Newold1 »

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:
PackardV8
Guru
Guru
Posts: 7619
Joined: Sun Jul 30, 2006 2:03 pm
Location: Spokane, WA

Re: 383 sbc build

Post by PackardV8 »

BLOCKMAN wrote: Sat Feb 09, 2019 11:12 amForgot 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
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
travis
Guru
Guru
Posts: 1611
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: 383 sbc build

Post by travis »

PackardV8 wrote: Sat Feb 09, 2019 11:47 am
BLOCKMAN wrote: Sat Feb 09, 2019 11:12 amForgot 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 😂
User avatar
Dave Koehler
Vendor
Posts: 7197
Joined: Mon Oct 04, 2004 11:19 pm
Location: Urbana, IL USA
Contact:

Re: 383 sbc build

Post by Dave Koehler »

On one hand that story proves reality is funny but so it the idea of a 150K mile SB from the 70s
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
travis
Guru
Guru
Posts: 1611
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: 383 sbc build

Post by travis »

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:
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 383 sbc build

Post by MadBill »

In some engines the main webs are so thin that
Block.JPG
two extra threaded holes make the assembly weaker... :shock:
You do not have the required permissions to view the files attached to this post.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
Newold1
Guru
Guru
Posts: 1963
Joined: Fri Apr 08, 2016 9:50 am
Location:

Re: 383 sbc build

Post by Newold1 »

Four bolt mains versus 2 bolt mains wont necessarily solve block failure issues. The example above of a 4 bolt block cracking at the main cap pad shows that magging a block and sonic testing for thin areas as Blockman reminded should always be done on any donor or replacement block! "Leave no doubt, check it out"! :wink:
The Older I Get, The Dumber I Get :wink:
F-BIRD'88
Guru
Guru
Posts: 9802
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: 383 sbc build

Post by F-BIRD'88 »

If you build the motor with the correct compression ratio for the fuel used, you won't have trouble with a 2 bolt main block. Detonation is what kills the mains and crank too. If you'll be using crap gas build with less cr.
DSRE388
New Member
New Member
Posts: 27
Joined: Mon Oct 22, 2018 7:56 pm
Location:

Re: 383 sbc build

Post by DSRE388 »

I have built a few 2 bolt 1 piece rms blocks with studs up to 514hp 502tq at 383-388cid and been lucky i guess!
Street strip deals making peak power around 5800-6100rpm
These were budget engines and i never recommend doing this now especially with Dart SHP blocks being affordable its a much better way to go for just a little more money and if you can't do that you can do a 2 bolt block with splayed center caps for extra strength.
Imho RPM and rotating/reciprocating weight and detonation are what kills most bottom ends and blocks like others have said
Post Reply