dlnoss

You could buy a bunch of them and keep them in stock if you want, seriously.

Used or new? -David

While I appreciate the referral, I'm really not interested in this business. Super Cub domes are more of a 'support' product than a standalone product. Thanks -David

Hey Alf, you aren't trying to steal a sale with a last-second PM are you? j/k

What do the domes and plugs look like? It looks more like a 'melt' than a 'break' making me suspect running lean. Detonation might pit the dome or break the plug electrode. -David

This might sound crazy but if the oring was out of place, if it was the wrong oring, or if the oring groove was too small it could cause that. It's hard to believe that a rubber oring could break metal but it can. I've seen it happen when the oring groove on a dome was cut too small. the oring can squeeze only so much. I'm not sure if it can really 'compress', only change shape a little but still occupy the same space,,,,,if the space is too small something will give. Enough of my ramblings, just thought I'd throw a possibility out there. -David

See if Modquad will warranty it.

Using the acorn nuts and copper washers should fix it. Do you have the acorn nuts? -David

With the right dome size, you will increase your performance and cooling without giving up any reliability. I don't know what the Modquad heads cost so I can't comment on their cost effectiveness. You could probably guess at my opinion of the Noss heads...

Yea, give me a call or most (but not all) of the BHQ sponsors carry the Noss heads and domes. -David

Lots of information here: Forgive me if I repeat what has been said so far. If you are using Banshee piston domes with Blaster pistons, the dome size will be deceptive because of the difference in crown volume. The trapped compression will be lower because the squish angle is steeper than it should be with the flatter Blaster piston. Besides the compression being lowered, the bottom end performance would suffer a lot. In your situation, a custom dome is probably a good idea instead of a 'shelf' or Ebay dome. I sent you a PM with some additional information. -David

Yea, what the other guys are saying. I wouldn't recommend 20cc domes on a stock motor at sea level on pump gas. Detonation will lift the domes and blow the oring. When you put it back together, run larger domes or higher octane (or both). -David

With the BHQ discount the Noss head with domes and everything is $234.00 but I don't have any blue ones right now. -David

21cc domes will give you less compression than 18cc domes. At your elevation, the smaller domes will help compensate for the loss of barometric pressure. 21cc would be better than a stock head but 18cc would be safe. -David

You should be fine with 18cc domes on premium pump gas unless you take a trip to lower elevations. -David

Mod Quad doesn't make anything for me. I make everything I sell (except nuts, washers, & orings). I've been making Banshee heads for about fifteen years. Alf44, Please don't say stuff about me or my products if you don't really know the facts. Call me if you want. -David

Just to clarify; The Noss head is a two piece design and uses stock studs. It looks kind of like a one-piece in some pictures. I made some prototype one-piece designs several years ago but stayed with the two piece head. It is more difficult and time consuming to produce but I was never pleased with my one-piece designs. I'm not slamming one-piece heads. The oring question seems pretty minor to me, maybe a difference of one to two minutes of installation time. On the other hand, the two piece design allows you to visually insure that the domes are positioned correctly before the top piece is installed. -David

Jerry, I guess I just that phrase used so much when hearing about politicians. Sorry if I took it wrong. Your products get great reviews also. The guys here on BHQ tend to weed out the bad guys pretty quick. -David

I don't want to start anything, and maybe I misunderstand the phrase 'in my back pocket' but most of the builders and manufacturers I do business with are at the top of their profession. They are the ones setting records. I consider most of them 'friends' not 'in my back pocket'. I don't like dropping names so I don't list all of them; it kind of seems unprofessional to do that. A lot of these guys are certainly capable of making their own heads and domes, many have the CNC equipment to do so, but find it a better use of their time to have me do it. A few dollars savings on a head or a set of domes, or some other product for that matter, isn't as important as getting a quality product in a short period of time. I appreciate their loyalty and do my best to earn it. I've not heard anything bad about any of the heads mentioned in this thread so I'm not slamming anyone. I just want to clarify where wrong conclusions could have been drawn. -David

Where you are or if you are riding at Little Sahara, you should be fine with 20cc domes unless your timing is advanced more than 4 degrees. Give me a call if you want to discuss it. If you order on the web site, be sure and enter 'BHQ' to get the Banshee HQ member discount. -David

You shouldn't have a leakage problem. Just take your time installing it, making sure everything is clean and the orings stay in place during assembly. -David

I'd say 21cc -David

The 'standard' cut domes I make should have .035" to .040" clearance with the standard base gasket. -David

I sell the billet ones but that one on Ebay for $18 shipped would be hard to beat. I would silicone it on plus use the hardware that comes with it. -David

If you are close to sea level, or below about 800', I'd recommend 21cc domes. -David