Relieving 8BA Block Poll

[1934calkid]

should a 8BA block be relieved 180 thousands for a street motor ? 286 ci..

[48 coupe]

I think the consensus is leave it alone. It's a waste of time, and will lower the compression.

[scooder]

Need to know the full engine spec, any port work, real honest desired use. To form an educated decision.
Martin.

[Deuce Man]

I have had flatheads both ways, unless you are trying for a new land speed record, you will probably never be able to tell the difference. Besides when the Chinese start making Ardun heads real cheap, you wont be able to use them if your block is relieved. Rich

[Ol' Ron]

I see no value in relieving a block for any reason except to lower the CR of a large displacement. engine. Relieving the heads works better.

[Ronnieroadster]

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My vote is yes certainly do the relief but .180 is to deep stay at the most at .100. Your building a Hot Rod motor at times your going to want to use the options by that I mean open her up get the RPM's above what some of the barners would consider a waste of fuel. Hell its a hot rod open her up pull some RPM's If you want to have some fun with your flathead and get her to rev definitely do some relieving.
One more thing your not going to see any drop in performance from the so called drop in compression from the relief all of my street flatheads have the relief and not one of them had any loss of power from such a positive improvement in flow. Now if your into gas milage leave the block alone but really fuel economy from a flathead heck get a Prious.

[JWL]

From the standpoint of science and using measured data there is no question relieving the block will REDUCE overall performance.

[Ronnieroadster]

Originally Posted by JWL

From the standpoint of science and using measured data there is no question relieving the block will REDUCE overall performance.

My measured data is seat of the pants proof cant get any better than that.

[1934calkid]

Where is Walt DuPont ? Pete the cam grinder and old Ron on this subject lol...

[Binx]

I used to think finding a 99T relieved block for street would be so cool, but the more I read, the more I was wrong. I still want one to sell to people who either still don't know or are running a blower.

Lonnie

[Pete]

Originally Posted by 1934calkid

Where is Walt DuPont ? Pete the cam grinder and old Ron on this subject lol...

I am here. I have nothing to say.

[1934calkid]

Just thought you might want to add your opinion into this conversation pete ?

[WestCoast]

was done on truck engines for torque, reduces compression, you would be better off un shrouding the valves

[HotRodmicky]

Get some french flathead heads , machine them for more lift( lots of meat) and you will have more flow than with a relive

[scooder]

I have an article by Don Fransico dated 1951, in this he refers to the reliving topic as controversial, if it was in '51 and is now do you think you'll get a definite answer?
As part of a combination it works, say real high compression with real tight transfer area. Now if the tight transfer area was causing a restriction, then reliving will help. As will reliving the head in the transfer area, probably better doing the head for ultimate flow in this case. So yes it does and no it doesn't in the same sentence. A 30 degree valve will see more gain than a 45 degree valve with the deck relived due to a more sides ways flow from the different angle.
I'd bet my dungarees that it is entirely possible to build a combination that prefers deck cut than head cut, the same as building one that prefers the head cut.
Its all gotta work together,
Thems my opinions.
Martin.

[48 coupe]

Ya got to admit ported & relieved sound faster, than just leave it alone.

[48 coupe]

Sill thinkin. Ported and relieved. just goes with edelbrock. eskey finton edmomds pitvon.malory,ect.,

[Mike B]

Let's tally it (for street use), JWL and Ron say no...okay...good enough for me...no experience with it, but I defer to those who have...again, street use...not circle track, drag racing, etc...

[Ol' Ron]

Having been to Bonnivell several times, I gravate to the Flathead powered cars. I've been privy to see inside some of these engines. I noticed very few were relieved. As one Aussy stated "bloody waste of time" I realize this doesn't answer the question. Up untill 20 years ago I relieved most of all the engines I built for street and racing. My last stockcar engine was not relieved and was the strongest one I build up to that time. However it had a different cam and port modification and the real reason I didn't relieve it was to keep the compression as High as I could. All engines were limited to 258 ci. This process of relieving is quite artistic, and requires some skill with a die grinder. Done the old fashion way of following the shape of the head gasket take time and the possibility of ruining a block by cutting into the seal area can be expensive and time consuming. SSSsssoooo, as the say"you pays your money, and make your choice" nuf said.

[40 Deluxe]

"ported and relieved, stoked and bored; will do 140 top end, floored"....ya' think?