207 block weight?

Dynra Rockets

New Member
First post. I remember when the 1980 Corvette came out and Chevy announced several weight reduction measures such as thinner body fiberglass and window glass, aluminum batwing differential and aluminum intake manifold. I also recall the announcements said that the heads and engine blocks went on a diet, blocks with thinner cylinder walls and different webbing/strengthening ribs. I have searched the internet and found a couple of references that the 1980-1985 207 blocks weighed about 14 lbs lighter than a comparable 010 block.

Can anyone confirm there is a weight loss with the 207 block? (fully aware of thinner walls of the 207 mean less overbore possibility)

My '69 350 engine is a 618 block.

R
 
welcome too the web site!
yes the pre-1968 blocks tend to have slightly thicker castings,
if chevy could save lets say 15 lbs of cast iron through the use of increasingly more precise casting technology per block,
on lets say 150-200k cars and trucks, thats well over 1000 tons of cast iron ,
they need not purchase and machine.
how much thicker Im not sure, as casting technology improved less metal was used,
most factory SBC blocks are rated to hold less than 400 hp, ,
and yes many will eventually fail if constantly pushed to stress levels exceeding 400 hp,
yes we all know guys that built 500 hp sbc engines using a O.E.M. block,
theres a huge difference between having an engines total accumulated stress, and can claim bragging rights,
that may produce 500 peak hp on a dyno run or infrequent drag strip trips
and some guy racing dirt track, every Saturday night,
who keeps the engine spinning 5000 rpm-7000 rpm most of the time.
yes you can push the limits but stress is cumulative and eventually parts will fail if seriously stressed.
but any decent machine shop can sonic test your block casting before its machined,
the single rear main seal blocks are even thinner
the DART blocks come in several configs, all use a higher grade alloy casting ,
thats considerably thicker than the stock O.E.M chevy production block.
if you intend to exceed about 450 hp and about 6000 rpm with a SBC on a regular basis,
Id suggest use of a DART block and ARP fasteners,
and SCAT 7/16" connecting rods and a forged crank


http://garage.grumpysperformance.com/index.php?threads/engine-block-cylinder-wall-thickness.976/

http://garage.grumpysperformance.com/index.php?threads/types-of-crankshaft-steel.204/

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.com/index.php?threads/what-con-rods-would-you-buy.942/

http://garage.grumpysperformance.com/index.php?threads/scat-cranks-related-info.10930/

http://garage.grumpysperformance.co...ds-vs-aftermarket-4340-connecting-rods.13321/

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/
 
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Thank you for that information!

In my case I will not exceed the design limits of the block, I do not plan to build to more than 350 crank hp (in reality probably closer to 300). My current short block is in need of a rebuild anyway so I thought might as well look for a lighter one as long as I am at it (my car is designed around light weight).

Has anyone put a 010 bare block and a 207 bare block on a scale?

R
 
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Thank you for that information!

In my case I will not exceed the design limits of the block, I do not plan to build to more than 350 crank hp (in reality probably closer to 300). My current short block is in need of a rebuild anyway so I thought might as well look for a lighter one as long as I am at it (my car is designed around light weight).

Has anyone put a 010 bare block and a 207 bare block on a scale?

R
Grumpy prefers bullet proof.
Learned just to roll with it.
Has merits aftermarket blocks.
Superior piston ring seal in a SBC.

I look at Value.
Big Chevy.
Pontiac 389-455.
Olds 425 V8 wins every time for me.
 
The C4 GEN CORVETTE blocks are good.
Chevy Truck blocks same era were used in every single Twin Turbo Callaway Corvette built. Used Compacted Graphite Iron.
A step below High Nickle and High copper content blocks. Without copper the iron Nickle is weak yet.
 
Save yourself a bunch of money in the long run and obtain a 1996-2000 Vortec truck short or long block.
You will be miles ahead of anything you might do with a 40+ year old block of questionable history.

OH yeah, welcome to the site.:D
 
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