Anybody have luck removing head AND base gasket?

Anybody have luck running engine without head AND base gasket?

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?

mechanickid said:

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.

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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 said:

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

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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!

Hey Tom,
Thanks for the heads up, no pun intended! I wish I had been taking pics so far....I don't know why I didn't. I suppose I'm always in a hurry and/or lazy. I am trying to get it put together to ride tonight if possible, but it's getting late so I gotta hurry. I have been doing some other repairs and upgrades along with the engine work, so it's taking a bit longer than usual. I will post results as soon as I can, hopefully that will be tonight! Heres a couple of pictures of where I am now. This is the bike that started it all for me. Its a Huffy Stalker; it has a factory matte black finish with all blacked out trim. It's the testbed for all my experimental work, and the basis for my handle here. It's an old ratty 12 speed!

Ok, I finally got it put together and managed to squeeze in about a 3 mile ride before the darkness. All I can say is wow. This has given me the best results yet. My powerband is a LOT wider, and there is quite a bit more low end power. And it really runs smoother. A lot smoother. Prior to this, my top speed on the flat surfaces was about 25-26 mph, tonight I got it up to 29 mph in the same spots, and the motor didnt sound like it was about to blow apart. The hill climbing wasnt as dramatic of an increase, however. I did have more power up the hills, but not like I have in the flats. I weigh about 250 lbs, so I am not complaining. The lower rpm power did give me a better stamina going up hills.....16-18 mph up relatively steep hills (without touching the pedals) with my weight is nothing to scoff at.
Prior to these mods, not necessarily in this order, I replaced : the spark plug with an Ngk, gasket matched the intake and exhaust pipes, completely gutted the muffler and brazed on a lawnmower muffler as a silencer, put an o-ring between the carb and intake, and lowered the clip on the carb needle one notch...thus raising the needle. Usually, I do one mod at a time so that I can keep track of power gains or losses, but I wasnt about to pull that cylinder off 8 times to track it that close. I would also like to add that the area around the head/cylinder where the head gasket once was is bone dry; absolutely no signs of leakage.
Prior to tonight, the biggest gain I got was the exhaust work, after gutting the muffler. I tried to drill out the baffle, etc. but I wasnt happy with those results. Gutting is the way to fly. There is a 1/2" hole in the end cap of the muffler exiting into the muffler. I am going to have to get lock nuts for the exhaust pipe, I cant go a mile without those frikkin nuts backing off.
Remember, the increase in power is the result of several small modifications. Right now I am happy with what I have, but I am going to get a tuned pipe soon. The SBP kit looks like the best deal out there, and Ghost and Pablo seem like really decent folks to deal with, although I do not know them. Thanks for everybody following along so far. I highly recommend cleaning up the ports, and the head gasket trick is worth the effort. Plus its pretty much free. Just watch your clearance, make sure the piston doesnt hit the head. I will update soon after more happy time!

I have a dynomometer hill of my own in my neighborhood, its what I gauge my standards by. It is approximately a 100 meter run, kind of steep, not sure of the grade or anything like that. When my engine was stock, it would not pull me up that hill without pedal assistance. If I didnt pedal, the engine would die about 3/4 way up. Now it pulls me up that same hill at about a steady 16mph average with no assistance, so I did happen to sneak some power out of somewhere. I would not say that I doubled the power, but definitely some gain. I do agree though that 'seat of the pants' power gains are usually deceptive....its really hard to tell. Now if I could just sneak some money by the wife for that expansion pipe......

I agree with you guys xlite. I just wanted to point out what all I had to do to make the little increase that I did. It took quite a few tweaks to get to an acceptable level of power, just enough to pull me weight around at a comfortable pace and know I can pull it off. Thanks for your input, I hope to pick up a couple of slant heads soon.

I did notice one thing that I didnt mention about my ride last night. The engine pulls really well up untill a certain rpm, and the its like the power runs into a brick wall. I dont have a tach yet so I dont know the rpms, but it revs up so far and then stays there. Its not like a rev limiter, but it will only rev so high as if it would not over rev and cause damage. I cant make it spin faster. Like it gets to 6500 rpm or whatever it really is and I could run it all day like that holding the throttle WFO. I checked and the slide does open and close all the way. What is that all about? Does that make sense?