Building a hot rod flatty.

[3W Hank]

I has a complete 46 engine and the style of the 32 3W coupe will be late 40’s ’racing’ so I will only use parts and ideas that a viable back then.

I will not race it but it will not be on trailer, I will not run hard and cruze just locally but I like the sound, look and smell.
I rather not use racing gas but I can.
When I say not run ’hard’, but I will throttle it.

As I been working with engines in business since mid 80’s and run dragracing in NHRA stock ( 426 Hemis ) and has full machine shop.
But these motor never crossed me. I think I balanced a 46 crank back in the late 80’s.

I guess the boys back then used the Mercury 4” crank and few ( my guess ) had them stroked 1/8 , or how did they do ?
My plan is to bore max 30 over so with a 4” give me 260 cubic.
My plan is to find old Navarro heads and a intake ( and dual carbs )
Not shore how CC is on this heads.
If I found a Mercury crank I might use one or a Scat.
Guess Scat has them at 2” pin and related rods.
Heard Scat might has issues on heavy metal but for me no issue but I heard them are not straight either, but I can fix that to.
Or is the Mercury crank better maybe.
If so do Scat make rods to them ( OE crank pin ) as I really like new rods.
And is the bearings a viable if I grind the crank ?
Next is pistons and I will use the Ross as modern rings.
I note they is domed, so how much is dome CC on them ?
Are the Navarro head has a chamber made, or ?
Then gasket, thickness and CC.
And copper or grafine ?
The cam I read the Kiwi L100 sounds good, or any other ideas ?

Regards compression, I read this motors do not like compression (?)
Better work on flow in air and find the balance.
-So what I describe on how to use the car, so how to think on stroke, compression, fuel quality.

-If no one here can answer me how to contact Ron Holleran, Rick Snell.

[KiWinUS]

G’day Hank and Welcome. My suggestion would be 4” Merc crank offset ground to 2” and get a NOS set of 21A or 91A rods. Or Scat rods for 2” crank pin. (Yes they make them). Get as much compression as you can but it is hard to get a lot. Piston to head clearance at .040” and valve to head.040” also really helps. Blend ports 8BA style valves and guides with bronze liners in guides. Great cam choice ( lm biased lol) A good distributor also very important. Feel free to ask any other questions. Good luck. Have fun and enjoy. Cheers
Tony

[solidaxle]

Prankster!

[3W Hank]

I can stroke a Merc crank to 4.1/8" if that is OEM on pin to start with and not hurted.
How long is the 91A rods ?
Is there modern pistons with that compression height ?
This OEM rods, was they for a 2" pin ? ( bearings std a viable ? )
And how good are they on the big end, sloppy - or ?
Its a cool factor to use old stuff, but a modern rod feel safe.
But I rather would use a Henry steel instead from China.

Why is there debate this motors don't like compression ?
What can they make with a Ross domed piston and the Navarro heads ( CC )
Whit this stroke = 4.1/8 and bore 30 over std.

Is the cam grinded in USA ?

[Ol' Ron]

If you PM me I will give you my pone No so we can talk about this build. My eyesight prevents me from long conversations here. Too many red lines.
Gramps

[3W Hank]

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Hi Ron !

Big thank's.

As I'm new here it was told 10 threads before I can PM a member, maybe you can ask staff to send me a mail and they can send my e-mail to you ?

[tubman]

Just post a few pictures of what you have so far, or maybe ask another, more specific question. It's real easy to get to 10 posts.

What do you think of this idea?

[3W Hank]

The Navarro heads, how much CC had thoose chambers 'normally' ?

[3W Hank]

I'm wonder if the Henry steel on crank/rods is matching new Scat or even better.

[3W Hank]

The 91A rods how good can one get the bigend on them ?
Normally old rods can be a pain.

[3W Hank]

On compression if going 4.1/8" stroke and 3/16" overbore it gets me near 300 cubics.
That will help on the compression.

[3W Hank]

The head gaskets, what to use here, thickness and CC.

[3W Hank]

If I found Navarro heads will Ross domed piston works ?

[3W Hank]

The Ross pistons, what is the dome CC on them at that bore ( 3/16" over std )

[3W Hank]

I saw on Scats web their 4.1/8” crank and piston bore at 3.3125” ( less than ’told’ max std + 3/16” )
So if I took a head at 74 CC and a gasket at 0.045” I got what they told 9.6;1 and that mean the Ross pistons has a dome at 12.65 CC ( deck at zero ) scat did not recommend a head at 65 CC. That mean a 10.9;1.
A note here, I dont know head gasket CC so dome CC at 12.65 is not correct, I might need call Ross.

Shore I could run racing fuel if going up att 11;1 but is there any adventages from pumpgas if 9.6;1 is ok.
If alu heads they are kind if forgive more than steel heads.
Normally steel heads make more power in a engine on same combo.
That’s a proven fact.
Again, I can run stock head in steel but what about ’flow’ ?

The Scat web give me this info even if I use Henry parts ( merc crank and the 7” 2” pin rods )

[Ken/Alabama]

I’d bore it to 3 5/16” . I have Ross pistons in mine with Navarro Heads.My block is bored to 3 3/8” with 4 1/8” stroke.

[3W Hank]

Oh, 3.3/8” that is big, how thin get walls ?
Your Navarro heads is that new ones or old and how much CC ?
What comp and gasket do you use.

I checked Ross web and they not tell dome CC, just height.

[3W Hank]

Anyone knows flow on stock steel heads ( might been modify ) vs Navarro ?

[Ken/Alabama]

Bought my Navarro heads new back when Barney was still alive. Had them milled to get piston to head clearance around .040 with big bore copper gaskets.

[3W Hank]

Very cool to meet Barney !
Do remember the CC in head ?
The copper gaskets what thickness and on CC in them ?