21cc heads to 19cc

**bigbluechevy454** · 12-08-2011, 08:15 PM

Would it be worth cutting my set of 21cc heads to 19cc or even 17cc. Kinda thinking 17cc with the 1.25 fishing motor gaskets its on a drag cut 260 running vp 110. Thanks

**Jay Smith** · 12-08-2011, 08:23 PM

If your JUST 1/4-1/8 mile drag racing , recreational ( NO WAY ! )

Jay

**funithesun** · 12-08-2011, 08:41 PM

I went to 17cc once. Modified exhause tuner to match. Boat jumped to more hp and torque than the gear cases could handle.
Founf better results taking stock heads and recutting the squish just raising compression slightly.

**patchesII** · 12-08-2011, 09:10 PM

You need a different gearcase mechanic. Lol

**bigbluechevy454** · 12-08-2011, 09:39 PM

Well I mostly just drag race and was thinking I could maybe do.17cc with fishing motor gaskets. Being there are easier to come by. Marina just down the st. How much compressor would that yield vs 19 with .75. Aren't fishing like 1.25

**johnboy 88 vegas** · 12-08-2011, 10:46 PM

I have been running a set of 2.0 150 heads (late model) on my 2.5 and the is exactly 10psi difference between the .75 and the 1.25 head gaskets on my motor. If ya run in saltwater the thin ones will start showing rust around the egdes on the outside of the head in a year. Never had this problem with the fatter 1.0 and 1.25 gaskets and the original surface is not the problem.

**Jay Smith** · 12-09-2011, 10:00 AM

Compression results is determined by how high and wide the exhaust port mapping is. The higher and wider the ports have been raised the lower the compression shouyld be..

**bigbluechevy454** · 12-09-2011, 05:27 PM

Oh jay I don't have compressor rings. In my motor would 19 or 17 be risking it to much

**D.Ally** · 12-09-2011, 06:03 PM

EGG shape in a hurry

**patchesII** · 12-09-2011, 06:27 PM

Bigblue, did you get my pm

**bigbluechevy454** · 12-09-2011, 08:19 PM

Oh sorry Erik didn't even notice I had one

**HStream1** · 12-10-2011, 06:28 AM

Just a suggestion. Why not buy a couple used sets. Have Jay cut then to your desired CC's. Then you can pick and choose. If you cut your existing heads and you don't like the results you are buying another set anyway. Unless you already have some laying around. If ypu don't like what you're done you can always sell them.

**bigbluechevy454** · 12-10-2011, 08:57 AM

Originally Posted by HStream1

Just a suggestion. Why not buy a couple used sets. Have Jay cut then to your desired CC's. Then you can pick and choose. If you cut your existing heads and you don't like the results you are buying another set anyway. Unless you already have some laying around. If ypu don't like what you're done you can always sell them.

. I guess my reason us I've figured someone other has done what I'm talking about already and could tell me the difference. Oh. How much compressor is gained per cc

**HStream1** · 12-10-2011, 09:01 AM

Originally Posted by bigbluechevy454

. I guess my reason us I've figured someone other has done what I'm talking about already and could tell me the difference. Oh. How much compressor is gained per cc

I think Jay already answered that for the most part in post #7.

**bigbluechevy454** · 12-10-2011, 11:08 PM

Originally Posted by HStream1

[/COLOR]I think Jay already answered that for the most part in post #7.

All I see is that jay said it depends on how much your much is cut will.determine the amount say a pair of 19cc will have on your motor. I'm saying how much compression wil u gain for every cc u take off. For example removing one cc is 15 psi

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