Compression/Engine build question

Ok. I am still stuck on the question of, "Should I zero deck my block?". The reason I am stuck on this question is because I am told yes and no. My build is going to be a mild build. I am using dished Probe pistons that Lem Evans advised me to get and whom I bought from. I am using regular gasoline. Still ain't got me a cam yet.
I want to get 400-420hp area and a good bit of torque.

Should I zero deck or not?

People told me just for my little build to not worry about it and just save the money. I am having a hard time to find someone to zero deck for me too...

Then others say get it zero decked because you will notice more power,etc.

It seems that a zero deck will get you to a point to get the right quench. My build is about a 13 to 1 compression and with a zero deck and a .045 thick gasket I would be at the .045 quench which Lem told me is where I would want to be. I am not for sure if that would be the right setup for you, mabe someone else will come in. I know Lem has the .040, .045, and the .051 thick gaskets so is all about how the block is cut. People have said .045 is about where you want to be but they never said on what kind of build so I guess it's about right for all..... dunno. Hope that helps a little.

Well my engine is bored .30 over.

I don't know whether to zero deck it with my mild build or just accept it like it is?

Depends on combo details, engine application, fuel, etc. For 425 hp, pump gas, and your emphasis on "torque," I would say that you should deck the block so as to improve quench effectivness.

Paul

Paul Kane wrote:Depends on combo details, engine application, fuel, etc. For 425 hp, pump gas, and your emphasis on "torque," I would say that you should deck the block so as to improve quench effectivness.

Paul

+1

Or put the piston .005" - .010" in the hole in case you need to deck the block again in the future or use different pistons etc... Do you know what the deck height is now? i.e. 10.320" or 10.300" ?

Make sure you mock-up your combo. My engine went from .028 in the hole to .007 when I changed rotating assemblies.

I don't know about a zero deck but I sure don't like a piston 0.036" in the hole if the deck is stock with the Probe pistons. Run the numbers to figure out where the piston will actually be. I would mill it some just to square the block and that would bring the piston up some too. People say that in your app that quench does not matter but good quench allows for greater detonation resistance as well as better torque production due to proper flame travel.

Well I will call them and ask them to measure the deck height as it is right now.

I can't find no one to zero deck me and plus I don't know if I should but my mild build I am going to do.
I am using regular pump gas.

I haven't got a cam yet.

Do you know what your compression ratio is right now?
What cylinder heads are you using and what did they cc?

I'd have to agree that if you are using a big dish piston, big chamber cylinder head with low compression ratio I wouldn't worry about it. I rode this horse before and realized that if by 0 decking the block I didn't gain a good amount of compression it wouldn't be worth the hassle and doubt you notice any differance. (Big dish piston with a 90cc chamber)
Yet if you have a flat top piston 80-72cc chamber it might be worth it. IMO

Once you get all your info, input it into this calculator and adjust the deck height to see what it does to your compression ratio. Give you a better understanding for you to decide for yourself if it's worth the time and money. You don't want to get the engine togather and then feel like someone talked you out of something you wanted to do.

http://www.diamondracing.net/cocalc.htm

jones wrote:Once you get all your info, input it into this calculator and adjust the deck height to see what it does to your compression ratio. Give you a better understanding for you to decide for yourself if it's worth the time and money. You don't want to get the engine togather and then feel like someone talked you out of something you wanted to do.

http://www.diamondracing.net/cocalc.htm

Good find jones.

I've always just done it on a spreadsheet that I made and now everything's on the internet. Seems like a waste of time to build any spreadsheets now, darn it.

Good luck with your build Dr. Ford!!

whatbumper wrote:

jones wrote:Once you get all your info, input it into this calculator and adjust the deck height to see what it does to your compression ratio. Give you a better understanding for you to decide for yourself if it's worth the time and money. You don't want to get the engine togather and then feel like someone talked you out of something you wanted to do.

http://www.diamondracing.net/cocalc.htm

Good find jones.

I've always just done it on a spreadsheet that I made and now everything's on the internet. Seems like a waste of time to build any spreadsheets now, darn it.

Good luck with your build Dr. Ford!!

Don't get me wrong, I love Excel just as much as the next guy but why re-invent the wheel!

I'm using D3VE heads. I may get them ported.

Dr.Ford wrote:Well my engine is bored .30 over.

I don't know whether to zero deck it with my mild build or just accept it like it is?

If you are having a "lot of machine work" done to this block for this build... 4 bolt splayed caps, oil mods, line bored...etc, I would consider leaving a small amount (.005-.008ish) to the deck in case of an error down the road. Once you invest serious money into a block, (or if it is a rare block like a Boss 9 deal) to make it last, you need to leave a little here and there for "just in case".

If all you are investing is having it bored and honed, then zero deck or as close as possible (averaging is likely). If you have an issue with something coming unglued, you can find another block to start over.

Could I just get it decked and no worry about zero decking?

Dr.Ford wrote:Could I just get it decked and no worry about zero decking?

If you just have it decked without measuring things... you are only guessing. What if it has been done before and ends up too short?

whatbumper wrote:

jones wrote:Once you get all your info, input it into this calculator and adjust the deck height to see what it does to your compression ratio. Give you a better understanding for you to decide for yourself if it's worth the time and money. You don't want to get the engine togather and then feel like someone talked you out of something you wanted to do.

http://www.diamondracing.net/cocalc.htm

Good find jones.

I've always just done it on a spreadsheet that I made and now everything's on the internet. Seems like a waste of time to build any spreadsheets now, darn it.

Good luck with your build Dr. Ford!!

I did the same thing when I created a spread sheet back about 10 years ago but not it's just easier to do it online