Anybody have luck removing head AND base gasket?

ratty · #1 07-22-2009, 05:18 PM

I have read a few threads here and there where people have run engine without both but it seems like the base gasket always gets put back on due to leaks. Has anyone successfully removed both with long term results.....improvements, gains losses.....etc?

reg454 · #2 07-22-2009, 07:46 PM

When I removed the lower gasket it was hard, it was stuck and i had to grind it off with a file I think they glued it on. But after it was off I used high temp rtv sealant the orange kind and no leaks but make sure to leave the top metal gasket on because you can damage the top from not enouph room.

Mike Hunt · #3 07-22-2009, 10:41 PM

really? taking the top gasket off will make that much of a difference?

mechanickid · #4 07-22-2009, 10:44 PM

it depends on your engine, with some the top dead center is already close to the head, and you can only use thin gaskets in both places before it "pings" with others your can remove both and even grind a little away and still be okay, i would experiment and see how it works, everytime you change it it effect the timing a little.

ratty · #5 07-22-2009, 10:48 PM

Quote:

Originally Posted by mechanickid

it depends on your engine, with some the top dead center is already close to the head, and you can only use thin gaskets in both places before it "pings" with others your can remove both and even grind a little away and still be okay, i would experiment and see how it works, everytime you change it it effect the timing a little.

When you say "ping" do you mean detonation...or do you mean physical contact between the head and piston? I haven't put any clay in there to check the clearance yet, but with both gaskets removed there is no contact with my particular setup.

**2door** · #6 07-23-2009, 12:13 AM

My question would be what are you trying to accomplish by removing the gaskets? The performance gain from the slight compression increase will be negligible at best and you run the risk of doing some serious damage to your engine either from an over lean condition from leaks or contact between the piston and head/plug. If your current gaskets are leaking, replace them but why remove them completely?
Tom

ratty · #7 07-23-2009, 12:52 AM

Quote:

Originally Posted by 2door

My question would be what are you trying to accomplish by removing the gaskets? The performance gain from the slight compression increase will be negligible at best and you run the risk of doing some serious damage to your engine either from an over lean condition from leaks or contact between the piston and head/plug. If your current gaskets are leaking, replace them but why remove them completely?
Tom

Truth be known, I have lapped my head and cylinder after cutting about .005 off each one. All this adds up to .040 total being removed by deleting the head gasket(which was .030") . I am basically looking for free horsepower. I have not started the engine since the mods. I have not even tried to calculate before and after compression, but it couldnt hurt. Not to sound lackadaisy, but if it costs me a piston or cylinder in the pursuit of more power, so be it.....parts are cheap. I have read several posts stating that just removing the base gasket and using only sealer, will net a significant power increase. Maybe it has more to do with the port timing, I dont know. I do know that my base gasket is worth about .035 of thickness. I am gonna try it with no head gasket first, then go on from there. I should mention that I also have trimmed the bottom of the piston skirt to open the intake port, and widened the transfer ports a wee bit, and removed the casting flash from the intake and exhaust ports in the cylinder. None of these are major modifications, but I just want to increase my power as much as possible (without going nuts) so that poor little engine can pull my fat a** up hills!

spad4me · #8 07-23-2009, 08:22 AM

Just my two cents.
The Most power increase is from a tuned pipe with a jet change.
About 1/3 more power.
Removing the lower gasket and trimming the piston skirt.
some more power.
I then tried opening up the transfer ports.
The easy way was to grind the top of the piston Dont go into the ring lands just remove material in front of the ports.
The pipe resulted in the most gain 1/3 more power.
The other mods added about 10 percent on top of the previous gains.

camlifter · #9 07-23-2009, 10:24 AM

i've been playing with these motors for awhile now and i've come to a few conclusions,
porting, raising compression, changing the length of the intake, trimming the piston, different carbs, and all the mods most people try don't really do much, i have a huge pile of useless parts to prove it. i've tried dozens of different combos in the pursuit of more power. yes you can gain a little, maybe, but a change in pitch of the sound of the engine or just the hope that all the time you spent wasn't wasted doesn't mean you really gained any power. the cost in time and money to the miniscule gains just isn't worth the trouble. NOW the things that do work, a tuned expansion chamber pipe is good for a big noticeable gain, also getting the carb jetted right makes a huge difference. the delorto and other carbs i've tried were no better than a properly tuned stock carb.

**2door** · #10 07-23-2009, 06:28 PM

Ratty,
I have no personal experience with raising compression (on a bicycle motor) but what I have heard from several people who have switched to the so called 'slant plug' head that does raise it, is that they have had clutch slippage problems especially on start up. This might be something you need to consider when you get the engine back together and running. Please post your results. And good luck.
Tom