Relieving 8BA Block

[dumb person]

No.

And not just no, but hell no. (as a response to the first post, just fyi)

[Pete]

Originally Posted by dumb person

No.

And not just no, but hell no. (as a response to the first post, just fyi)

Everyone is entitled to his opinion and I respect that, no matter what it is, BUT,
I would like to know how many that say "no" have actually built a FAST street engine and tested it with and without a relief?
Remember, for a valid test, you CAN NOT run the 2 tests with the same heads.

The relieved block will win every time.

[Vics Stuff]

I relieved my block for street use. Used 11:1 Offenhauser heads. 3/4 old school cam , tri power set up and my truck runs well. Been on the road since 1985 and never any engine issues. Just did a lot of reading and felt that was the best thing for this engine.
Do not regret it.
Vic

[dumb person]

Originally Posted by Pete

Everyone is entitled to his opinion and I respect that, no matter what it is, BUT,
I would like to know how many that say "no" have actually built a FAST street engine and tested it with and without a relief?

You can't put ardun heads on them very easily.

[JWL]

So many experts and so many myths.

[marko39]

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I knew a old timer who raced stock cars in the 50s and asked if they ever relieved the blocks on the flatheads. He told me they tried it but never saw any improvement on the track. Fwiw.

[old Tom]

I talked with 2 flathead giants in my time. One was Stan Lamelino at Cordova Il In 1962 and John Bradley in 1998 I asked each of them if their blocks were relieved and they both replied Yes.
Roger Huntington in his book and Don Francisco in his articles both stated that relieving the flat head motor increased the horse power. We are talking full out racing engines not street cars. Could all of these Giants of the past be wrong or is it because they are not able to take advantage of the modern technology we now have. Maybe some food for thought. Although John Bradly was still racing in the late 90,s and early 2000. Thank You

[Pete]

The original question was:
“ Should a block for a street car be relieved 286 ci”.

This can NOT be answered accurately without more information.

Static “street” display in a museum?
Daily driver/commuter?
Occasional street driver to the drive-in, parades or car games?
Fast driver to run at weekend drags and driven to work on weekdays?
Built to flip for quick cash.
Budget concerns?
Stock OEM heads?
Modified heads?
Driver driving style and habits.
How much hp can you be satisfied with.

[JWL]

Since I was the crew chief for Stan Lomelino, up to the time he stopped racing, I feel qualified to respond---It is true in the early days we would spend countless hours porting and relieving our engine blocks. This had to change when we started using 100% nitro and the racing schedule expanded wildly to a minimum of 3 events weekly. Eventually we found that softening the eyebrows combined with "normal" porting worked best and gave us the most power. There are several reasons why that is true which I explained in my book.


As an aside, Ken Kloth, perhaps one of the more well known Flathead racers, learned to avoid relieving the Flathead block in order to get top performance.


The secret (if there are secrets) is in the port, valve pocket, and head. Not the block relief. Doing wet flow studies will help us understand that the area being "relieved" does not play a significant roll in the breathing potential of our Flathead engines.

[Ol' Ron]

I modified a junk aluminum head to determine the affect of the transfer area had on flow. I sterted with a 4 deg angle and went up to a 12 deg angle. After 8 degs no improvement in flow took place with the port valvr combination i had in the block. Although this did increase flow, it also reduced the CR drastically. I then got as piece of wood and made up a bunch of combustion chamber designs t find the one that flowed the best with the highest CRr This was a wedge chamber the same as the Chevy 348/409 style. I waanted to have Egge make a set oof blanks for me so I could machine the heads and pistons to match, but the cost was much too high. Later i discovered that this chamber had already been used in a Bonneville engine. This is probably the best design so far, untill some one comes uo with a better one.
When it comes to running a fast car I believe the normally aspirated ones require th highest degree of engineering. Stuffing an engine with fuel or a blower is a lazy way to make power. However, I repect those that do, because they have to hold them together.

[Pete]

Originally Posted by Ol' Ron

When it comes to running a fast car I believe the normally aspirated ones require the highest degree of engineering.

You are sure right about that.

[JWL]

Not sure what you mean when using the term "engineering"? There are many little problems to be overcome to get maximum performance from any set of components. Mistakes in component selection or status are more readily exposed with boosted or boosted and fueled engines. There is something to be said for the level of refinement in engines of the Pro-Stock or Competition Eliminator categories where a gain of 5HP on a 1200HP engine is considered a great achievement. But the amount of work. study, engineering, and problems is present in all the full competition classes.