Complete from intake to oil pan. Acquired from East Coast Supercharging and sent to LME Late Model Engines to be built. I have the dyno sheet, dyno video and parts list of the build. It’s been sitting in the crate packaged by LME in a climate controlled air conditioned heated shop since approximately 2012. Rare find as it’s purported only 500 blocks were made available by Chevrolet Racing Program. I’m having trouble posting the attachment in this post. I can provide information to your email and I’ll try to reply to my own post to see if it will allow me to do it. I’m asking $25k OBO

 

DM'd just to share info. Bump for a hot block.

 

Please post a photo or two.

Thanks, George

 

I will get my mechanic to go by the shop to take some photos of the crate and engine along with new 90lb and I think 180lb injectors in the box etc that will go with the engine. Anything in my shop that’s engine related will be thrown in for free(blue and red electric fuel pumps, electric water pumps, damper, NX intake nitrous set, chrome nitrous bottle, FAST throttle body and anything else that in there I bought for the project that never happened) this list is from memory so not 100% sure that’s why it’s free and not to be included in asking price of the engine. I’m getting older so no new projects for me and have been on the forum 20years so I’m motivated to sell and willing to negotiate.

 

C5R 427 all aluminum engine. Only 500 or so was released by the Chevrolet Racing Team Program. RARE!

 

A little back story on the C5R block. Good luck with the sale.

( I will delete upon request.).

George


C5R Blocks
Part # 12480030 C5R Block
Below is an abbreviated version of the C5R block process.
There are differences between parts made and distributed by GM Service Parts, GM Performance Parts,
and GM Racing. This block comes from the GM Racing program and as such the original intent was
never to resale this part to the public to meet the demand for a “reasonably priced” big bore block to build
GEN3 engines. It was developed for one purpose and one purpose only; to win races and World
Championships for the C5R racing program under the required engine rules.
The block is not a “reverse engineered” piece. In-fact GM Racing made some developmental Siamese-
bore castings by modifying the stock cores from the factory production blocks. These developmental
blocks failed the durability test. That is why the C5R block was designed. The original production
LS1/LS6 design would not hold up to the 24hr durability testing at the HP levels required to win the 24
hours of Le Man. The new LS7 block (soon to be released) was designed from the continuation of
lessons learned from the C5R racing program.
The requirements were determined and standards were set, the least of which was that the block had to
meet the demands of the 24-Hours of Le Man. GM Racing worked with their in-house designers and
engineers, they made 3D Models, tightened production engineering tolerances, defined casting
requirements and detailed the heat treating processes before the first prototype block was ever made.
The first blocks were cut into sections, X-rayed, inspected, tested for material hardness, etc. - before one
engine was ever assembled. Then durability testing was started to determine any shortcomings and
make improvements if necessary. The requirements to become a C5R block are way beyond any other
standards that current block manufacturers use today.
The block is cast from premium 356M aluminum. It is a modified form of virgin 356 aluminum material
specifically developed from the GM Racing programs. Each batch of blocks has several sample test bars
cast for material specification testing at the foundry. They must have the correct “356M Recipe” or the
batch is rejected.
It is then taken to a facility for heat treating requirements and a special cleaning process to remove the
sand from the casting procedure. From here it is taken to another facility to be “hipped”, also known as
the “HIP” process. HIP is the acronym for Hot Isostatic Pressure. An expensive procedure that is
demanded in industries where there is no room for error (Aerospace, NASA, etc) and where the end
product must be a representation of the highest degree of strength and integrity possible from the
material in use. This process puts the blocks in a sealed vessel where a vacuum is first used to remove
the room air and any possible contaminants. The vessel is then filled with high pressure Nitrogen (up to
30,000-psi) and then heated to the required temperature and sustained for a determined amount time.
The cooling process is also a controlled procedure to insure maximum strength and proper heat treat.
This extreme high pressure and heat removes almost 100% of the internal porosities that are generated
during the casting process. The hipping procedure will clearly show defects that might not have been
caught until the block had been subjected to actual race applications under high stress and heat. The
material integrity is greatly enhanced because of hipping and the material strength and fatigue life will
increase significantly. Any block that exhibits an exterior surface hole after hipping is considered a
defect. Most manufacturers will weld and re-sandblast any small defect or holes to cover up the
imperfection. Not GM Racing. The blocks that passed the hipping process are then taken for an X-ray to
determine if there are any internal voids, cracks, imperfections or flaws that could lead to a block failure.
20% of the castings will have been eliminated by this time. Note; the hipping process is so extreme that
most castings will exhibit some shrinkage from the high pressure. Therefore, one must take this into
account during the initial design phase. Raw castings may need to be dimensionally increased from 1%
to 2% if hipping is to be applied.

 

I love learning about this stuff. Thanks for the fascinating tech process and history of that block.

Erik 🤟🏻🏁