JTalmage Posted June 17, 2015 Posted June 17, 2015 So I'm sure some of you have seen my Model A thread that I had recently. I want to put a V8 in it instead of the 4 cylinder and make it a nice period hot rod. Problem is, all of the flathead v8 engines I have in the parts box are entirely too big in scale, and the transmissions are very long, and look like toploaders or muncie's. What would be the best choice for a v8 swap in that old kit? I was thinking the Revell midget racers w/ their v8/60 engine but when sat in the chassis they look extremely tiny, and the transmission looks soo small it almost looks to me to be a 2 speed or something.. Can anyone steer me in the right direction? I've learned soo much about hot rods in the past few years (coming from the Mustang world orignally) but there are still soo many things to learn! Thanks!
3100 chevy Posted June 17, 2015 Posted June 17, 2015 I just cut up whatever I have just like the traditional rods were made.
JTalmage Posted June 17, 2015 Author Posted June 17, 2015 Normally I wouldnt mind cutting stuff up, but engine detail is soo hard to correct after cutting and gluing I'd prefer not to.
Jantrix Posted June 17, 2015 Posted June 17, 2015 The Mono 30 Model A is 1/24 scale so I'm wondering how all your spare engines are to big in scale?.
JTalmage Posted June 17, 2015 Author Posted June 17, 2015 Well that's exactly what I was thinking too... but have you seen the size of the old AMT 49 Ford flathead?
1930fordpickup Posted June 17, 2015 Posted June 17, 2015 Jesse is you have the Monogram 49/50 Ford truck that is a great flat head.
Ace-Garageguy Posted June 17, 2015 Posted June 17, 2015 (edited) The A-V8 was (and is) a very popular real-world combination, and almost always refers to a flathead-powered car (among old farts, anyway). You DO usually have to clearance the firewall to do any A-V8 swap, by the way. I've done several rods based on the Monogram A, mixing and matching scales as necessary. Any of the available flathead engines out there would look fine in the engine bay of the Monogram A, except the V8-60, as you mention, which is a very small engine indeed. All of the 1/25 flatheads are scaled fairly well, so just pick one you like. The most common transmission in reality on a period-correct car will be a '39 or so top-shift Ford box. The Revell '32 kit that includes a flathead ought to fix you right up with something that looks about right, or if not, try the Revell '48 Ford woody engine (I think it has a fairly correct gearbox). It was also very common on the real period A-V8 swaps to remove the old crossmember and weld in a trimmed '34 X-member, to get the right grearbox mounts, and to stiffen the chassis somewhat...really needed on an A V8. The desired Ford "top shift" transmission looks like this, and is loosely represented in the AMT '36 and '40 Fords, plus some of the Revell kits...the '37 Ford truck too, I believe. This one of mine has a 1/25 OHV engine in it, an engine that is larger than a flathead, and it fits fine. Edited June 17, 2015 by Ace-Garageguy
Guest Posted June 17, 2015 Posted June 17, 2015 Don't know if it's the "best" flat head there is. But the flat head in the the Revell '48 Ford custom is pretty nice. It comes with aftermarket heads, dual carbs/intake, bell style breathers, chrome generator and chrome headers. This one is out of the box with details added.
Ace-Garageguy Posted June 17, 2015 Posted June 17, 2015 Great looking engine, Roger. That's one kit I don't have yet. Gotta get one now.
1930fordpickup Posted June 18, 2015 Posted June 18, 2015 (edited) Bill and Jesse the early 48 Ford Convertible had Motor City Flat Head heads and intake. Not sure if they have been changed now or not. Edited June 18, 2015 by 1930fordpickup
JTalmage Posted June 18, 2015 Author Posted June 18, 2015 Man, thats a good looking flathead. I would totally buy one of those 48's... I've been picking them up and putting them back down at the store... dunno why. I'd hate to just sacrifice it for the engine though!
Ace-Garageguy Posted June 18, 2015 Posted June 18, 2015 Man, thats a good looking flathead. I would totally buy one of those 48's... I've been picking them up and putting them back down at the store... dunno why. I'd hate to just sacrifice it for the engine though! So, put a Y-block in the '48.
Casey Posted May 27, 2020 Posted May 27, 2020 On 6/17/2015 at 11:17 AM, Jantrix said: The Mono 30 Model A is 1/24 scale so I'm wondering how all your spare engines are to big in scale?. Using Rob's reply as I am in a similar predicament-- building a 1/24 scale '37 Ford, and wanting to keep things consistently in 1/24 scale. Having both 1/24 Monogram '36 Ford and 1/25 Revell '48 Ford flathead engines on hand, I placed them side-by-side and snapped a few comparison pics: The white/top engine is the 1/25 Revell, both both are nearly identical in overall size. The 1/25 Revell engine is actually a bit longer than the 1/24 Monogram engine, and both cylinder heads are shaped slightly differently (hard to see in the blurry third image, sorry), but without 1:1 measurements on hand to check both, it would be difficult to tell which scale both engines are, at least to my eyes.
Ace-Garageguy Posted May 27, 2020 Posted May 27, 2020 (edited) 41 minutes ago, Casey said: Using Rob's reply as I am in a similar predicament...it would be difficult to tell which scale both engines are, at least to my eyes. Neither engine shown really correctly represents what the top of the block actually looks like, so even if you had 1:1 dimensions, there's "interpretation" involved. And it's been my experience that engine scaling in kits is generally pretty poor across the board. For instance, the supposed 1/24 Buick nailhead in the Monogram Orange Hauler is pretty much dimensionally identical with both of Revell's 1/25 versions (old parts-pack / Ivo Showboat and the recent '29 Ford). The only Ford flathead V8 in a kit that I recall being really kinda obviously small is in the Lindberg '53 Fords. Even though I'm usually kinda anal about this stuff, in your shoes, I'd probably just use the bigger white one and call it good. I don't currently have any flatheads around, or I'd measure for you. But the width across the heads is listed as 30" on a supposedly reputable site, and 24" on another one, so there's that. And for what it's worth, all the machined surface dimensions on all the blocks are the same. EDIT: I'll do some checking and at least get you a nominal length for a head. Edited May 27, 2020 by Ace-Garageguy
Ace-Garageguy Posted May 27, 2020 Posted May 27, 2020 (edited) 1 hour ago, Casey said: ... but without 1:1 measurements on hand to check both, it would be difficult to tell which scale both engines are, at least to my eyes. Extrapolating from a good online photo of the top of a block with a 3.1875 inch bore, a 1:1 cylinder head is about 18.88 inches long overall. Edited May 27, 2020 by Ace-Garageguy
Flat32 Posted May 27, 2020 Posted May 27, 2020 (edited) Actual 1:1 early block is 25.625" from front machined face to machined transmission mount surface. I have complete computer models of the 59 block and 1939 transmission. White one looks better except for strange inaccuracy in driver's side head mounting surface at the rear. Black one is more correct in this detail. Edited May 27, 2020 by Flat32
Ace-Garageguy Posted May 27, 2020 Posted May 27, 2020 19 minutes ago, Flat32 said: Actual 1:1 early block is 25.625" from front machined face to machined transmission mount surface. I have complete computer models of the 59 block and 1939 transmission. White one looks better except for strange inaccuracy in driver's side head mounting surface at the rear. Black one is more correct in this detail. What have you got for the length of a head?
Flat32 Posted May 27, 2020 Posted May 27, 2020 18.68", but the block and head castings can vary and this dimension is not determined by machining. I believe nominal was probably 18.75". The machined head mount surfaces on the block are 7.19" wide on the driver's side and 6.81" wide on the passenger's side.
Ace-Garageguy Posted May 28, 2020 Posted May 28, 2020 (edited) 4 hours ago, Flat32 said: 18.68", but the block and head castings can vary and this dimension is not determined by machining. I believe nominal was probably 18.75". So...pretty close to the 18.88" I derived from the photo. Roughly one to two tenths difference in 1:1, or about .004"-.008" on a 1/24 scale model. I'd say that's close enough. EDIT: Casey, as Raymond says, the ends of the cylinder heads were not usually machined, on OEM or aftermarket parts, and overall you could probably expect there to be about 1/2" variance in length among a group of factory and aftermarket heads. Some aftermarket alloy heads are also sometimes a little longer to give more meat around the end studs, for more reliable gasket sealing. Another note...the gearbox behind the white engine isn't the desirable "top shift" box everybody usually wanted. Edited May 28, 2020 by Ace-Garageguy
Flat32 Posted May 28, 2020 Posted May 28, 2020 Henry Ford had his foundry pattern makers use precision measuring tools that the toolmakers and production machinists used. I doubt if the head castings varied in length by even plus or minus 1/16". In my somewhat limited experience with aftermarket aluminum heads I never saw a variation much more than 1/8" in length. Don't forget it was Ford that manufactured the Johansson gage blocks used throughout industry as precision certified standards. You'd probably be surprised at how close Henry's manufacturing tolerances were and how all were checked.
Ace-Garageguy Posted May 28, 2020 Posted May 28, 2020 6 minutes ago, Flat32 said: Henry Ford had his foundry pattern makers use precision measuring tools that the toolmakers and production machinists used. I doubt if the head castings varied in length by even plus or minus 1/16". In my somewhat limited experience with aftermarket aluminum heads I never saw a variation much more than 1/8" in length. Don't forget it was Ford that manufactured the Johansson gage blocks used throughout industry as precision certified standards. You'd probably be surprised at how close Henry's manufacturing tolerances were and how all were checked. You're correct, of course, but I wasn't clear. What I should have said is that in a random group of cylinder heads including stock and aftermarket, it would probably be possible to find a 1/2" variance in length by design...not poor casting work and sloppy tooling. Not too far back, I worked with a shop that did extensive work with these engines, and I seem to recall seeing variations in length between 21 and 24 stud heads, and particularly longer ends on some of the unusual aftermarket alloy heads we saw. I could also be wrong...but for Casey's purposes, having that 18.75" nominal length for a head should allow him to get an engine that looks close to scale-correct.
Casey Posted May 28, 2020 Posted May 28, 2020 The 1/24 Monogram '36 Ford cylinder head* measures .725" long, so x 24 = 17.4" The 1/25 Revell '48 Ford cylinder head measures .767" long, so x 25 = 19.175" (Navarro heads) The 1/25 Revell '32 Ford Sedan cylinder head measures .775" long, so x 25 = 19.375" (Edelbrock heads) * = definitely some type of aftermarket ribbed head, with no manufacturer markings
Flat32 Posted May 28, 2020 Posted May 28, 2020 That is interesting. The 1/24 Monogram is more closely 1:25 scale while the Revell 1/25 examples are more closely 1:24 scale. ,725 x 25 = 18.125 .767 x 24 = 18.408 .775 x 24 = 18.5 So if Casy's model A is 1/24 either of the Revell engines are pretty scale accurate for it. All of the builds with Flatheads that I've seen on this forum look very OK to me.
Rocking Rodney Rat Posted June 3, 2020 Posted June 3, 2020 1/25th vs 1/24th....I see very little difference and consistency from kit to kit. I mix them up and together all the time and don't think twice about it. (I look forward to your responses)..... -RRR
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