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CVO Technical => Twin Cam => Topic started by: Billy Swift on August 13, 2012, 11:05:40 AM

Title: 110 head gaskets
Post by: Billy Swift on August 13, 2012, 11:05:40 AM: hello, i have a 2011 street glide cvo with quite a bit of work done to the motor, it has 10.5 pistons in it with a .30 head gasket. all is good and makes good power, but as soon as the temp gets over 85 and with a rider on back it starts to knock and ping. my question is does anyone know what the compression loss would be if i go to a .40 head gasket?

Thanks for the input
Title: Re: 110 head gaskets
Post by: GMR-PERFORMANCE on August 13, 2012, 01:54:20 PM: You will drop approx .2-.3 tenths of a point.. It may not be as much lowering the comp ratio as getting the tune dialed in..
Title: Re: 110 head gaskets
Post by: Midnight Rider on August 13, 2012, 02:03:46 PM: Quote from: GMR-PERFORMANCE on August 13, 2012, 01:54:20 PM
You will drop approx .2-.3 tenths of a point.. It may not be as much lowering the comp ratio as getting the tune dialed in..

X2...Often, tuners want to squeeze that last bit out of a motor so the Dyno Chart looks good, but at the expense of overall rideability (timing is advanced too much). The ECM can compensate for that IF it's tuned properly. Losing a few HP/TQ numbers is better than detonation IMO.
Title: Re: 110 head gaskets
Post by: grc on August 13, 2012, 02:16:55 PM: You left out some important information, like what cam you're running.

If the bike runs fine until the temps get high, I'd suggest it would make sense to get the tune fixed versus tearing the heads off and swapping head gaskets for a very minor decrease in compression. Sounds like the tune is a little too aggressive, and that tends to be a common problem with a lot of tuners. Even if you did change the head gaskets, you might still need to adjust the tune anyway. Take it back to the guy who tuned it and have him fix it.

Jerry
Title: Re: 110 head gaskets
Post by: HILLSIDECYCLE.COM on August 13, 2012, 03:21:31 PM: Probably has settled in now, and the tune needs a quick brush up.
Scott
Title: Re: 110 head gaskets
Post by: Billy Swift on August 13, 2012, 03:37:43 PM: Thanks, i will check with tuner before making a mechanical change
Title: Re: 110 head gaskets
Post by: HILLSIDECYCLE.COM on August 15, 2012, 06:24:27 AM: Sounds like the best approach. :2vrolijk_21:
Scott
Title: Re: 110 head gaskets
Post by: Cvostu on August 15, 2012, 06:34:55 AM: I have a question here,,, what is the thickness of the stock head gaskets that comes in the 110. I did a few things when I got my sg3, cams- exhaust and a tune only. I didn't do head gaskets at that time. Wasnt ready to crack into a brand new motor yet. :nixweiss:
Title: Re: 110 head gaskets
Post by: North Georgia Hawg on August 19, 2012, 06:24:12 PM: Stu - Stock head gaskets are .055", and are made of a metal core with little points all over it, with nasty sealant around that. Took me awhile using Goof Off and a plastic paddle to get all of that crap off of the cylinder tops and head mating surfaces, then clean out the heads and cylinder bores and rough up the mating surfaces just a bit.

The Cometic MLS gaskets I installed come in 3 separate pieces, riveted together on tabs (that I cut off) that sit outside of the mating surfaces... .030" total thickness.
Title: Re: 110 head gaskets
Post by: Cvostu on August 19, 2012, 06:29:12 PM: Thanks Ken,,, I didn't realize they were almost double the .030 cometics. Ive seen where the heads need o be sanded when replacing them. :nixweiss: