Sad, but true. This was the case with mine. Make sure you mag AND pressure test them. I had one that the shop never pressure tested. Did all the machine work and when I pressured tested, it had a 10" crack in the valley.
Don't settle on the cam. The Clay Smith 272-2 is a good grind, except it is very low lift. Something around .325". For what you want to do, you really should have more lift. Something within .375"-.400"
100% agree with this don't settle on cam alot of flathead guys are stuck using (the cam they use) not the cam that would work best because its to "radical" lol
You have gotten a lot of good advice so far. Just remember, building a Flathead is not for the weak at heart. lol
Here is a picture of an 8BA Edmunds Custom head mounted on an 8BA. Notice if you look straight down the spark plug hole you can't see any of the valve head. If you do this with stock heads, or Edelbrock's, or Offenhauser's, you will see a good portion of the valve head through the plug hole. I have never had any Navarro heads, so I don't know about them. Also note that the 7/16" guide stud in the lower upper left is very "loose" in the head bolt hole. This is because just about all aftermarket heads made lately have oversize bolt holes to make them easier to remove when studs are used. When I install a set of after market heads these days, I use two lengths of appropriately sized aluminum tubing on two of the stud holes to positively locate the head on the block. A better way would be to "pin" the heads (like late model engines), but I don't have the equipment to do that. I have found that this works just fine. Also, make sure you use special hardened washers under the bolts/nuts.
I has not decide a cam. Maybe the 400JR or the Winfield 1A, or ? They get more lift than the Clay Smith. One migh wonder if bigger valves is good vs some portings. I think I like the combo 30 over bore at 3.25 and stroke at 4.15 make 275 cu ; in. Mote cyl wall. One question. Say I offset grind the Merc 4” crank to 4.15”. Is the 91A rods ( I might mention wrong rod ) all Ok ( and is it modern bearings ? ) Oterwise it’s a good idea maybe to use a new I-beam rod and CSB 2” bearings, but will it fit correct ? I asked my CP guy if the had light castings to a 1.375” C-H, and they do. They also has thin rings 1/16” or 1.5 mm or 0.04” or 1 mm. The 1 mm steel and 1 mm napier and a 3 mm oilring would sling the pistons easy less friction eith goid oil control. The Edmund Custom heads sounds great ! Really like that idea ( Thanks ) I read at myford web ( a older forum ) the 3 carb set-up overpower any 2 carb set-up. -It would be nice get +200 HP NA on racing fuel.
Why the preoccupation with racing fuel? You won't be able to get enough compression to require it out of an N/A flathead unless you do some real heroic things, and then the engine won't be streetable. (By racing fuel, I assume you mean hi-octane gasoline, not something more exotic.)
I like the smell and its burn nice. I see this as a race car but it will be on streets, but Very limited. One can ask, why so much fuzz has 200HP, well... I had a billet Volvo block up for linebore recently and little over 2L and over 12K RPM and customer told me 1.400 HP on streets. In my world a FH is way cooler.
2 carbs or 3 for your idea of combo. That cam is one ex H&H sell and they had the Navarro stuff to. Not a bad idea.
Either 91A or 21A rods are used with the offset ground Merc crank. They will require the old style floating bearings, which are expensive and hard to find. That's why the new H rods and their easy to find insert bearings are so popular now. If you have to pay the going rate for bearings, and all the costs to rehab the old rods, it might get close to the cost of the new rods and insert bearings. Put some pencil to paper to find out for yourself. Actually, it may actually be even cheaper for you, since you are closer to China and the new rods would take a shorter trip to your door.
A friend runs an 8BA in a Model A pickup. Been running fine for years. All of a sudden it is building pressure in the radiator. It has expanded the top tank and spurted water from the cap. I have ideas, but what is the first thing that comes to mind with you guys out there. It runs cool, even when belching. I told him to pop the Edelbrock heads off and check for visible cracks, and have the heads pressure tested. Am I going in the right direction?
Alchemy. Yes, new rods make sence of course. What year was the Merc 4” made and do they has 1 or 2 oil holes ? I think they came out 49 and they do has 2 oil holes and rod journals was bigger than 2” ( but did they had modern bearings ? ) If new rods ( modern bearings ) does it works on a offset grinded Merc crank ( 2” rod journals ) What bearings, Buick or CSB - 2” ) If not one has to invest in China part crank to. I hope the Merc crank was from the 40’s and has 2 oilholes, then my buddy Verdi can make me new H-beam rods and I use CP pistons. Made me feel Much better.
The 4" Merc cranks were made from 1949-1953. They had two oil holes. The reason the new rods are economical is because they can use a readily available bearing, but I've got no idea what the original application is. You continually say "CSB". I am assuming you mean small block Chevy? We abbreviate that to SBC. And I'm pretty sure the only usable parts from a SBC for a flathead are some valves, and maybe the rod nuts. Anything else would cause it to seize up.
You should reach out to Auliz (spelling?). I believe he’s in Finland and he seems to know his flathead stuff and could connect you to info/parts closer to home...
Finland and Sweden has not one word in common, but most Finns do speaks Swedish if they like. I’m a Fin to but it was many moons ago or several generations. They come over here on 1500’s as Sweden did own Finland and my family was from a type that was not popular ( from Savolax ) and they burn forrest to get better soil, so Sweden had bring many over ( as it was s problem ) and where this people cone from no one knows, but they was not ’real’ Finns. I heard Finn was spoken as late as the 20’s in the remote area of Sweden where my grandpa came from. It was law here they must speak Swedish but it was ol school and remote area. My grandpa had many strange ideas, he had to ex sleep with head to north, and forrest was where he like to be in etc. —-/ SBC, they has a 2” rod pin and dont ex Ross use that bearing ?
Bad cap or crack ? Is it running cool on both banks ? Remember its like two separate cooling systems until it mixes in the radiator.
He's running a 6 pound cap that is new, and he used a temp gun on both banks, and they were the same, and not overly hot. I tend to think crack, so I have suggested pulling the heads for a look at the block surface. He's thinking of changing to a 302 (yuk!!) so I said if all else fails, he can have one of my good 8BA's.....
6 lb cap on old original radiator that was made for no pressure could expand the tank . Did it occur after the new cap ? Check for proper fit and check cap for proper release pressure . Ive had 6 lb caps hold pressure to almost 20 lbs and it was a good stant cap
If you're going for a period correct car for the year 1946 then the 4" Mercury crank is wrong because it didn't come out until later. If you want to use the Mercury crank in the '46 block, by all means do it. It will give you the same little "oomph" that the guys back in the '50s got by doing it. Whatever you do, don't overthink it. I hope your finished engine gives you the same satisfaction mine does.
Engines is from 1946 but rest of parts was used hot rod stuff ca 1940’ ish as 36 rearaxle, brakes from 40, transmission 40 in a 32 frame. The idea that the car was build around 1948 and the engine ( 100 HP 59A ) was found at the local junkyard, so style is very late 40’s. He also has a airplane junkyard nearby so he took sests out ( lighter and need vs a hard chop that was done late 48 ) The ’guy’ also saw Spencers roadster and went home and pinched in his frame.... His father workes as metalman, he was a machinist. When the Merc engines came out with the 4” stroke he bought a new crank and got it offset grinded and found a set of 21A rods. This was late 49 when the first fire up was done and he was ready to fill up high octane fuel in trunk. Rest is history. I think he started OE heads but if it was replaced by visit Edmunds head shop, well the story might continue... ;-) -That’s my idea/concept. Father and son was involved in pre dragracing but was at this era just on streets. —— I like engine works and been build custom set-up since mid 80’s ( but never was into FH ) But now I’m, and a full machine shop is aviable. Dyno aviable, both bench and chassie close to me.
Hmm, what I'm talking about is the one Specer had for test at 49. Thank's upgrade me on the roadster, I thought it was done 1950 in public.
This pic was supposedly taken in 1952, see the fresh weld/grind work in the front horns and engine mounts. https://www.jalopyjournal.com/forum...ncer-roadster-from-52-69-more-details.536915/
I always did like the 32 frame horn in front but when I realised Larry Rollings coupe was pinched in, I had no return back, but typical, I was hoping on 1949 as I think he made test on it, I might be wrong.
I has a idea for a new head in billet aluminium from the concept of 'thermo flow'. I found out how the Jr dragster engines used for chamber deesign, and they used a flat top piston at deck and gasket clearance piston to head at 0.060" and CR was 7.5;1. It might be other ideas for a FH, but se picture of the Jr version. Engine concept ; Bore 3.25" Stroke 4.125” Custom 7" H-beam rods with 2” bearings Custom flat top pistons at a C-H at 1.385" Steel ring 1 mm top, 1 mm second cast napier and a 3 mm oilring. Deckheight at ca 10.45" Piston to deck = 0 Cometics gaskets at 0.045” compressed thickness = ca 13 CC Ruff calculated chamber CC = ca 75 Valve pockets 0.45” Cast mech cam at 0.40" in lift. That gives a CR at aropund 7.5;1 The idea is to mill out a head with chambers and sparkplug holes and boltholes in a billet high quality aluminium plate ( based on cool effect around the exhaust valve ) Then a plate above that to hold the water and copy the ORD design ( se picture ) and inlet as on the 59A. ( I has a neighbour that has a HAAS 5 axle machine ) -What do you guys think of this idea ?
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