After much concern on my part and further research into the subject, the Fel-Pro 521SDs just aren't thick enough. Well, they
could be but from what I've gathered the only real way to find out is to assemble it, run it repeatedly to redline under load, and see if the bearing clearances/rod stretch/heat expansion will allow it. That sounds like an expensive way to discover something wasn't right. You may recall that I've got some experience in that department, with this specific engine no less.
I determined that a .060" gasket would be nearly ideal, but that's not an easy gasket to find. OK, it is but it's not an easy gasket to find that doesn't have an 8-11 week lead time at the moment, which is Cometic's current backlog. I don't want to assemble this thing on Thanksgiving or Christmas Day. While looking, I stumbled across a company called
Flatout Racing that makes head gaskets. Summit had
one set of Flatout's .064"-thick gaskets with a 4.150" bore. Unfortunately, I don't deal with Summit anymore. Plus, since the gasket bore directly affects my precious compression ratio, I wanted a smaller gasket bore if possible.
I called Flatout directly, and got a delightful woman named Candi on the phone. I know better, but wrongly assumed they had a receptionist. They don't, and Candi knows her business very well. I told her what I had and what I thought I wanted. She said that in their experience you want a gasket bore at least .020" larger than the bore, so my 4.080" gasket was not a good idea.
"What's the next size up?"
"We can make them to whatever bore you want. We can do 4.090" no problem. That would be ideal."
The time involved was an immediate concern. I don't want to do this in the snow. "How long does something like this take?"
"If you'd have called before 10
we'd have gotten them shipped to you today. I can put a rush on it and probably still ship them this afternoon Next Day. Would that work?"
Jesus. "No, that's not necessary. If they go out in the next week that's sooner than I'll be able to use them."
"OK, well we can make it happen if you need 'em quickly."
We went through the finalization process and she verified I had a W2 340 with a 4.07" bore and that I wanted .064" RCC
* gaskets with coolant passages (they make them either way) with the 4.090" gasket bore. She took my card info, gave me a total, and we were done.
* RCC stands for Rubber-Coated Copper. It's a copper gasket with a thin rubber coating to improve passage sealing.
The phone call alone was one of the best customer-service experiences I've had in a long, long time. Candi made the call a lot of fun in addition to being very capable at her job. Imagine my delight when I got a UPS ship notification and tracking number around
4PM the same day. The gaskets were already in UPS' possession, it wasn't a "shipment arranged" email. She rushed 'em anyhow at no additional charge. I would've had them Friday but for some reason UPS screwed up and sent them to the wrong distribution center (they'll still be here Monday).
Inexpensive?
Nope. My total came to about $185, but there's not much else I could do at this point. Pinching nickels has cost me dollars so I'm done screwing around. With service like that, I'm not going to complain one bit. In fact, I
saved about $50 over the Cometic MLS gaskets that would've taken two months or more to get here, which weren't available in that bore size anyhow.
From the service standpoint, I can't recommend Flatout highly enough. I've no doubt the gaskets will work well but I'll report back with parts in-hand and in-engine when those events occur. If you need bespoke head gaskets, give Candi a shout.
The new gaskets put my carefully-calculated static compression ratio at exactly 9.80:1. I'd be happier with half a point or more beyond that, but it would require milling the heads. On the flip side, dynamically it puts the engine well into pump-gas territory--even cheap 87 octane (not that I'll use it)--so I can stop using expensive race fuel mixed with pump 91. I could get the dynamic compression up with a different cam (or advancing what I've got), but we'll see how it all shakes out with what's in there now.
