Phathead Racing big bore domes

[J-Madd]

I've got a "Phathead" coolhead and I asked them to make some big bore domes for a 421 Cub. I checked the squish clearance and got 0.030. I measured at the thinnest part of the solder which was all the way at the end. I had them cut some more, supposedly 0.007 and still got 0.030. I think they have sent big bore Banshee domes (for Banshee pistons), but, as I now know, you use Blaster pistons with a 421 Cub. and the dome shape is different. Can these domes that I have be used with this motor? The squish goes from 0.030 to 0.060 on the solder (outside to inside.) The local machine shop guy said he could take some more off, but thought the angle/curvature of the dome is supposed to match that of the piston. Without taking any measurements, I'm pretty sure these domes have a steeper angle/curvature than the dome of the piston. He said he could cut the dome to the angle of the piston and probably get the minimum squish clearance to be around 0.040 (which about where it needs to be), but I'm not sure I want that. I have no idea how all of this will affect performance. To be safe, I think I'll order a NOSS head and domes, but I just wanted to know opinions about these domes, if for no other reason to educate the machine shop guy and others who may have run into this problem.

Edited February 4, 2007 by J-Madd

[wesw]

get with noss machine he can make you set of whatever you want.

 

good guy.

[J-Madd]

get with noss machine he can make you set of whatever you want.

 

good guy.

 

Yeah I just ordered a head and domes from him. BTW I didn't mention that Noss and PD domes do not fit the Phathead. That is why I had to get them to cut the domes. It's a sweet setup for stock bore, though. The head is one piece that slides over the domes. From what I remember about my other Noss head is that it has 2 pieces that more take patience to install.

Edited February 4, 2007 by J-Madd