276 stroker from 35 years of parts

[Tim Ayers]

Originally Posted by tubman

Yep, Barney Navarro was also an advocate of "pop-up" pistons in flatheads.

Navarro's pop-up piston design is quite different than what we see here.

The piston was made with an actual protrusion that rose above the deck and would match accordingly to a corresponding pocket in the head.

[Ziggster]

Thought I would share what I measured on my build.

C59A
Stk crank
0.060” over (Egge pistons)
C7RA-A cast iron factory Ford heads
Felpro head gasket - 0.055” thk
NGK sparkplugs
Block and heads were skimmed (not sure how much), but it was just to “clean” them up
Heads were tightened to spec

Head to piston clearance - 0.073”
Sparkplug to exh valve clearance - 0.128” (valve closed).

[Ziggster]

Some pics. Looking back at these pics (taken last year), makes me know wonder if the exh valve will hit the spark plug? I never did cycle it a few revs to check. Hmmm…What says the experts? I have the Isky 1007B.

[GB SISSON]

Les the machinest told me he took a very small amount off the decks to clean them up. He doesn't seem like the kind of guy who would angle mill the block without mentioning it to me. Been working on accessories today. I'm going to re-gasket and install new lockwashers on my chosen oil pump tomorrow, but I have to play a bit of catch-up in the woodshop too.

[Tim Ayers]

Originally Posted by GB SISSON

Les the machinest told me he took a very small amount off the decks to clean them up. He doesn't seem like the kind of guy who would angle mill the block without mentioning it to me. Been working on accessories today. I'm going to re-gasket and install new lockwashers on my chosen oil pump tomorrow, but I have to play a bit of catch-up in the woodshop too.

Judging by how much of the "eyebrow" under the valve is still present, I would agree that it was a minimal cut.

[GB SISSON]

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As if I needed more drama, I will present something that hasn't been brought up yet. In post 246 I mentioned that all this measuring and clearancing to get to a 40+ state was performed with a used head gasket that measures .062. I also stated that the Best Gasket website gives a compressed gasket thickness of .052. Somewhere I lost track of that other .010". Yikes, I'm back into carving out the combustion chambers again. Last night I went down and decided to see what kind of numbers I got on a typical cylinder with the new standard head gasket from my Best set, which outa the box is .058. I was sick of all the math required, and the chance that a piston hit the fire ring and alter my numbers, so went up to the woodshop and ripped some hard Eastern maple strips at EXACTLY .052. I made extra so I could pick five pieces about 8" long. Placed them vertically at each end and the center, the the two others I carved a scoop to fit between the pistons. These I used a dot of contact cement to prevent wandering. Did some balls and results were predictable. Need more carving.
I feel my carving skills were quite good and improved with practice, using the worn small grinding disc which I'm gonna say is about 3 1/2" or so. This disc has the typical worn out convex lense shape that occurs naturally from general use. Not pictured yet, but I later followed this up with a flap sanding disc of similar size and wear. The majority of carving to this point has been from zero to .010, and now I will need to remove another .010 in places. My gut feeling is this is ok. The chambers were virgin at the start.
My game plan moving forward is to wait til the big bore gaskets arrive from Olson's Gaskets and using a NEW sharper sharpie, outline the larger size on the head and dive in. I will continue to utilize the wood strip spacers for the remaining steps as it is so direct. And yes, I tested them after last night's experiment and the maple shows absolutely zero compression from six snug headbolts. Somebody should market a .052" thick aluminum 'head gasket'. Everything I searched just said 'use an old head gasket', so I did.

[51504bat]

Somewhere along the line I ended up with this metal "gasket" Have no idea what it was used for but maybe for determining clearances or to correct over milled heads? Thicker than a normal gasket but would be easier than using an actual gasket? Or maybe not.

[Bored&Stroked]

The block has been decked - as having the piston a bit above the deck is not a bad thing - as it helps tighten up the quench without having to mill the heads a bunch. If you think about it, you have a .052 or so head gasket (when torqued down) - which puts the head profile that much higher than the piston. So, having the piston a bit above the deck brings it a bit closer to the chamber top. Of course, it all depends on your specific combination of parts - but I think he is going to be just fine!

Note: When I'm building a custom performance engine, I have whatever deck and main saddle work done first, then I put the crank and rod in the engine and exactly determine what my compression height needs to be for my given combination (heads, pistons, gaskets, etc).

Then I order the pistons from Ross with my specified compression height (which tells them where I want the pin). This gets me exactly the quench that I want. There is just a minimal upcharge from Ross to do this - so it is worth the extra time/effort to get it exactly right.

[tubman]

A couple of things. First, I never use radical high lift cams (usually just a "MAX-1") and have never found a problem with clearance over the valves. I do put a large foil ball on each valve head on the initial check, just to be sure.

Second, I should clarify my remark about "pop-up" pistons. It was said partly in jest and partly to lend encouragement to this build. To be precise, the pistons DO protrude higher in the block than stock Ford units, and unless other changes are made, will require a relief in the head. Not nearly as extreme as Barney's but nevertheless a "pop-up" in concept.

[GB SISSON]

Thanks Denny, but is the work I'm doing on the heads above the pistons the relief you are mentioning? It should not take me too long to get everything to .040-.045 and finally put this behind me. If the experienced builders here think I am pushing the limits on thickness over the pistons I can explore my other head options, like all those 8ba heads. I've never been one to give up or lose interest and set a project aside for the future, so as soon as my big bore gaskets arrive I will bust out the sharpie and the grinder and tackle the high spots in the heads.

[Tim Ayers]

Originally Posted by tubman

A couple of things. First, I never use radical high lift cams (usually just a "MAX-1") and have never found a problem with clearance over the valves. I do put a large foil ball on each valve head on the initial check, just to be sure.

Second, I should clarify my remark about "pop-up" pistons. It was said partly in jest and partly to lend encouragement to this build. To be precise, the pistons DO protrude higher in the block than stock Ford units, and unless other changes are made, will require a relief in the head. Not nearly as extreme as Barney's but nevertheless a "pop-up" in concept.

Tub,

Totally get it and I was being Mr. Literal with my comment.

Back when I bought my heads from Barney in the early 2000's, he told me about his Hi-Dome heads and had some for sale.

I was really interested until he said the only piston company making the pistons for this set up was Arias and they were $100 a piece.

Being a newlywed with not a pot to pee in, no way would I get kitchen clearance for a $800 set of pistons. I barely got it for the $630 for a set of his heads.

[Bored&Stroked]

I think your method is just fine. Maybe not as dimensionally accurate as a big doming tool in a big milling machine, but good enough. Also, one needs multiple doming tools - for the two quite different piston shapes.

You're almost there - glad you took the time to go through this - it is quite important that you don't slam your pistons into the heads! LOL Also, a tight quench really wakes up a flathead.

[tubman]

"Relief" is kind of a odd word here. Generally, any time you remove material from the combustion chamber, you are "relieving" it. Where the misunderstanding comes in is that "relieving" has a special meaning with flatheads, and specifically refers to removing material between the valve pockets and the cylinder. But here you will be relieving the head. It was probably a poor choice of words on my part. I am well aware of Barney Navarro's pop up pistons and related heads are much, much more "extreme" than what you have.

As I said, this was a poor way of interjecting a little humor ad encouragement into your build. I see now that it was misplaced and I apologize for it. Carry on; from all I can see, you're doing it right.

[GB SISSON]

I'm starting to smile again. Thanks Dale, and Denny I never thought for a minute that anything you said was offensive. Heck, the only Barney I recall from the '60s had a last name of Rubble.

[Bored&Stroked]

Just for informational fun, here is some information that I captured from Barney Navarro in the early 2000's - specifically related to pop-ups and his then experimental "High-Dome" heads.

He and I spent some time discussing the traditional flathead performance heads and I talked about the Harley KR and recommended that Barney incorporate some of the characteristics of the Harley KR into his cylinder heads. My next-door neighbor was super knowledgeable about KRs - had at least 6 of them in his garage and had built many for racing --> Daytona, Flat Track, Side-Hacks, etc.. His name was "Snuffy" Smith - he was like a second father to me and was a super intelligent mechanical wizard (in many things). My knowledge (and jugs, heads, etc) - came from Snuffy.

Another guy I know - Tom G. - helped Barney for a bit (said he was going to build a Bonneville car). Barney was happy for the help but had a falling out with Tom once he saw what Tom was up too. I knew Tom back in the day as well - he seemed like a decent dude at the time (was a shame that he wasn't on the up and up with Barney). Anyway, you'll find this to be an interesting read - glad that I captured it many moons ago!

This article was prior to H&H working out a deal with Barney to buy the rights, patterns and associated stuff from Barney. That happened relatively shortly after I penned this article.

Enjoy:

Navarro High-Dome Heads - DHays2022.pdf

[GB SISSON]

Interesting stuff Dale, thanks. There were some colorful folks and great minds in the racing scene in those days.

[Mart]

That's about the craziest but CLEVERIST thing I ever saw! Great work GB!

[Bored&Stroked]

Poor man's doming tool! Love it!

[cadillac512]

Love it! Gary, you are a thinker. You constantly invent ways to get the job done with whatever you have on hand, and it's with impressive results. Well done.

[Als48]

Wow, GB! That is impressive. Keep up the good work.

Al H