Speed-Talk is running on www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Most Power from Stock 400-509 casting?

General engine tech -- Drag Racing to Circle Track

Moderator: Team

econo racer
Expert
Expert
Posts: 646
Joined: Mon Nov 26, 2007 11:44 pm
Location:

Most Power from Stock 400-509 casting?

Post by econo racer »

Would a 600 hp 434 last a few yrs bracket racing at 12-1 compression shifting at 6400 rpm. Using a scat crank and rods. will be run on E85 only :D
mag2555
Guru
Guru
Posts: 3165
Joined: Sun Sep 18, 2011 11:31 am
Location:

Re: Most Power from Stock 400-509 casting?

Post by mag2555 »

With no detonation taking place , why not🤠
steve316
Expert
Expert
Posts: 628
Joined: Fri Apr 13, 2007 10:06 pm
Location: St.Joseph,mo.

Re: Most Power from Stock 400-509 casting?

Post by steve316 »

Why tie up money in a block like a 509 casting; when you can buy a dart shp ( shp pro better yet) for a few dollars more. You don't have the clearance
problems, thin cylinder walls or the mains wanting to walk. Also the wore out lifter bores, sell your block to someone who want a low hp street engine.
I would not use a oem casting for anything over 450 hp. Just my opinion, good luck.
Racing68
Pro
Pro
Posts: 379
Joined: Sat Feb 10, 2007 10:27 am
Location:

Re: Most Power from Stock 400-509 casting?

Post by Racing68 »

I know without splayed caps they only last about 15-20 nights about 500-700 laps in a dirt circle track car. Depending on how many passes you make a year it should last at least 2 years, longer if it's 1/8 mile. Also for these reasons I have not used a stock 400 block in a race engine in well over a decade.
Lizardracing
Pro
Pro
Posts: 347
Joined: Fri Sep 10, 2010 2:38 am
Location:

Re: Most Power from Stock 400-509 casting?

Post by Lizardracing »

Racing68 wrote: Mon Jan 04, 2021 9:53 am I know without splayed caps they only last about 15-20 nights about 500-700 laps in a dirt circle track car. Depending on how many passes you make a year it should last at least 2 years, longer if it's 1/8 mile. Also for these reasons I have not used a stock 400 block in a race engine in well over a decade.
Lots of guys in my area running 509 GM blocks ate 550-625 in circle track cars for several seasons. I'm one of them.
A aftermarket block is still a good idea but they also cost twice the amount, not just a few dollars more.

I have a $1000 in machine work on my current 406. A dart block starts at $1800, then needs finish worked and ends up at $2200.....Tha'ts not exactly a few dollars more.
User avatar
mt-engines
Pro
Pro
Posts: 306
Joined: Fri Sep 27, 2019 12:35 pm
Location: MN

Re: Most Power from Stock 400-509 casting?

Post by mt-engines »

I have built quite a few in the low to mid 700hp range that are still being used today without issue. 377-434.

I have one thats getting a freshen up here at the moment that hasn't even had the springs changed since it was built(2006). no signs of fretting on the caps or oiling issues, overheating, cracking etc. As far as power goes, it was never on the dyno but showed over 600hp worth of et. Just a 7000rpm bracket engine.

I have also had luck with one that made near 800whp with an 8:71 blower, guy has been cruising it to car shows for probably 6 years. Ive seen more engines destroyed because of the tune up, vs because the block was stock..

but if you were to start a build from scratch and wanted over 700hp and over 7000rpm, dont waste your time correcting a stock block. The extra $1k is worth it.
User avatar
mt-engines
Pro
Pro
Posts: 306
Joined: Fri Sep 27, 2019 12:35 pm
Location: MN

Re: Most Power from Stock 400-509 casting?

Post by mt-engines »

econo racer wrote: Mon Jan 04, 2021 4:35 am Would a 600 hp 434 last a few yrs bracket racing at 12-1 compression shifting at 6400 rpm. Using a scat crank and rods. will be run on E85 only :D
Yes, if your tune up is on, the problem with the e-85 and stock blocks is they wear the bores pretty bad over time with even a great tune up. You can get away with more compression if you'd like also.
miniv8
Expert
Expert
Posts: 691
Joined: Mon Sep 11, 2006 5:22 pm
Location: ICELAND

Re: Most Power from Stock 400-509 casting?

Post by miniv8 »

econo racer wrote: Mon Jan 04, 2021 4:35 am Would a 600 hp 434 last a few yrs bracket racing at 12-1 compression shifting at 6400 rpm. Using a scat crank and rods. will be run on E85 only :D
Yes.
Do not tighten the heads more than GM specs, ever.
Magnús Aðalvíkingur Finnbjörnsson
rustbucket79
Guru
Guru
Posts: 1843
Joined: Fri Apr 07, 2006 8:23 pm
Location:

Re: Most Power from Stock 400-509 casting?

Post by rustbucket79 »

A 434 might last a few years in a stock block, or it might not. I’ve had great success with some, disappointment with others. (Split cap/fretting/ugly main bearings/various cracks where there were none prior)

For the price of the entire build, why not buy a SHP block and get years of life with better material, thicker bores, better main caps, and less grinding for clearance. It’ll seal a head gasket, not split a head bolt hole, and more importantly, the bores seal much better. You get a block with many rebuilds in it, not investing a bunch of machine work into the block’s last build.

Think about it.
ProPower engines
Guru
Guru
Posts: 8197
Joined: Sun Jan 21, 2007 1:16 pm
Location: Victoria BC Canada

Re: Most Power from Stock 400-509 casting?

Post by ProPower engines »

I have done a few for unlimited circle track class's and by the time you clean and mag check the block and add steel caps then correct the cam tunnel and lifter bores as well as bore and deck the block you have spent more then an SHP block does with money left over.

Some guys will do it over time cause they can't put the spare change away for a block which seems like more often then not but.................
Real Race Cars Don't Have Doors
GARY C
HotPass
HotPass
Posts: 5998
Joined: Tue May 14, 2013 10:58 pm
Location:

Re: Most Power from Stock 400-509 casting?

Post by GARY C »

econo racer wrote: Mon Jan 04, 2021 4:35 am Would a 600 hp 434 last a few yrs bracket racing at 12-1 compression shifting at 6400 rpm. Using a scat crank and rods. will be run on E85 only :D
Cylinder wall thickness would be the main issue, I had one friend that ran both a 421 and a 434 around 675 hp na and 175 to 300 hp of nitrous and never broke one, we ran a lot of stock blocks from 377, 400, 421 and 434 most never broke and others never made it through the burn out box.

If you can sonic ck the block and be sure it has thick walls then you should be safe but if not you can spend $700.00 or better on one that breaks the first time out... I did it twice.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
rustbucket79
Guru
Guru
Posts: 1843
Joined: Fri Apr 07, 2006 8:23 pm
Location:

Re: Most Power from Stock 400-509 casting?

Post by rustbucket79 »

FWIW GM decided to save a few bucks and retain the open head bolt holes in the 400 blocks. They also sculpted cylinder wall material at each of those head bolt holes, so the wall thickness in those 5 areas is pretty damn thin, under 1/8”. The Dart block does not suffer from this design flaw.
User avatar
mt-engines
Pro
Pro
Posts: 306
Joined: Fri Sep 27, 2019 12:35 pm
Location: MN

Re: Most Power from Stock 400-509 casting?

Post by mt-engines »

rustbucket79 wrote: Wed Jan 06, 2021 11:22 pm FWIW GM decided to save a few bucks and retain the open head bolt holes in the 400 blocks. They also sculpted cylinder wall material at each of those head bolt holes, so the wall thickness in those 5 areas is pretty damn thin, under 1/8”. The Dart block does not suffer from this design flaw.
Design flaw???? Heck if you were to design a 265hp 400 cubic inch engine.. mind you only 265hp and has to be mass produced. would it be beneficial to your company to have .300" cylinder walls, blind bolt holes.. essentially retool everything? No.

The LS engines have some Racing related design problems. But both engines do exactly what they were designed to do.

IM SURE THE OP IS WELL AWARE A DART BLOCK WILL HANDLE MORE POWER. HE ASKED IF 600 HP WILL LAST IN A BRACKET DEAL. THE ANSWER IS YES
PackardV8
Guru
Guru
Posts: 6370
Joined: Sun Jul 30, 2006 2:03 pm
Location: Spokane, WA

Re: Most Power from Stock 400-509 casting?

Post by PackardV8 »

For an engine shop, the question is piece-work machining or a complete build with our name on it and your tune.

If a bucks-down guy brings in a 400" block and asks for bore, hone, deck, line hone and takes it with him, his decision.

If a guy comes in and says, here's a 400" block, build me a 600hp bracket engine, probably not going there any more.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
rustbucket79
Guru
Guru
Posts: 1843
Joined: Fri Apr 07, 2006 8:23 pm
Location:

Re: Most Power from Stock 400-509 casting?

Post by rustbucket79 »

mt-engines wrote: Thu Jan 07, 2021 12:23 am
rustbucket79 wrote: Wed Jan 06, 2021 11:22 pm FWIW GM decided to save a few bucks and retain the open head bolt holes in the 400 blocks. They also sculpted cylinder wall material at each of those head bolt holes, so the wall thickness in those 5 areas is pretty damn thin, under 1/8”. The Dart block does not suffer from this design flaw.
Design flaw???? Heck if you were to design a 265hp 400 cubic inch engine.. mind you only 265hp and has to be mass produced. would it be beneficial to your company to have .300" cylinder walls, blind bolt holes.. essentially retool everything? No.

The LS engines have some Racing related design problems. But both engines do exactly what they were designed to do.

IM SURE THE OP IS WELL AWARE A DART BLOCK WILL HANDLE MORE POWER. HE ASKED IF 600 HP WILL LAST IN A BRACKET DEAL. THE ANSWER IS YES
What is your problem, pal? [-X
Post Reply