okay first things first, its not getting a flat head so don't bother, I already have a couple stovebolts so I dont need another money pit for an engine now as jj would say, with that said I have a 49 merc that some one waaay long time ago clipped with a 79 caddy front end, it was done rather well and I am poor so I am inclined to keep it unless the track width is screwed, either way it is a power steering set up which totally kills the need for a vintage engine in my opinion. so here are the things I am looking at, oh and it will be a daily so Gas Milage is important as is budget as I am poor. stock small block with a rv cam and a 600 edlebrock carb with a 700r4 or caddy 500 with a th400 or maybe a 4180es or 460le? or a 352 with a c6 any other suggestions? I like the idea of the small block for availabilty and cheapness of parts however I am apprehensive about a stock small block struggleing with such a big car. seems like from what I have heard I would get close to the same mpg with the caddy 500 and have 3x's the power. the FE is just a good running engine I can get for cheap, its a 2bbl all stock engine from a 63 galaxie, it just needs new freeze plugs. remember though guys this engine is not about cool its about affordability, reliability, MPG and what a rebuild would cost down the road if it had to happen. hell I could always put a 4bt turbo diesel and run it off of cooking oil
Though I am not fan of the belly ****on SBC, for that reason, they are nevertheless, good engines. There is absolutly NO reason an sbc would not be adequate for a '49 Merc. Any medium to full size GM car in which SBC's were installed were as heavy, or heavier, than your Merc. The 500 Cad is an interesting option, not especially heavy despite it's outward size with gobs of torque but the combo of it and a 400 still exceeds the weight of a 350/350. However, the 500 with a rear end geared very tall, low to mid 2's, should deliver decent economy. But if you are looking for max economy, weight is the enemy. IMO, the FE is a non-starter for consideration. They are heavy and not particularly fuel efficient, actually a little hoggish in that regard. Ray
******knuckles has a cad 500 in his truck and told me that he found that a 500 is only like 50lbs heavier than sbc. I am pretty sure he said 50lbs... anyways yea I see your point on the FE. He also was saying how the caddy 472's and 500's have a higher nickel content in the blocks and therefor last substantially longer milage wise.
Caddy 472 or 500... I am dropping a 472 into my 51 mercury. It has the th400. The 472 doesn't make my engine stand droop like a chevy 454 does so I would say its light. The only thing that looks to be a obstacle is the oil filter location but you have a late model front clip so you might not have to notch the front frame rail. Cad500parts.com has some different angled oil filter housings that might be helpful. Caddy motor should be fun with all the torque they can make.
The other thing you want to check out on the Caddy is the pan sump location. I'm thinking the RWD versiomn have mid sump and Eldo's had rear sump. If you can use the standard RWD pan you're way ahead costwise, as Eldo pans have become a bit expensive. Ray
Nothing wrong with caddys but you said you wanted to possibly rebuild the engine in the future. It costs more than double to rebuild a caddy than a 350-400 sbc engine. For good money-return, I'd use a 400 sbc...lotsa grunt and they practically bolt-in place..plus cheap to rebuild in the future.. That said, If I had an opportunity to score a 500 caddy/400 turbo with 100,000 or fewer miles on it, I'd prolly do it for coolness/big power factor. Best deal is to buy a running 70s caddy coupe deville. YOu can scavenge the caddy for all the important stuff...wiring, tilt/tele column, engine/******, seats and all the A/c stuff...big deal is the wide, 4 core radiator and it's shroud. Don't forget to use the stock caddy 7 blade clutch fan too. I robbed a 75 caddy of all the radiator/fan/shroud when I put a 350 chevy in my 49 ford coupe....first test was taking the car to GoodGuys in DesMoines....was over 100 degrees and I idled all over the fair grounds all weekend at 170 degrees...that stuff flat works!
I would find a mid 70's cad and pull the engine, trans and interior out of it.... gatta have some of those layin' around that are inexpensive and running. Or a mid 70's cougar with a 351...
I grew up with a 51 Merc. That old flat motor with a 255 and the Borg Warner overdrive pulled it around quite well. I don't see why an overhead valve motor in the 300 to 350 cubic inch small block range wouldn't do just fine. Modsville Mercs go on looks more than speed anyway.
you know me, sbc and a 700r4. cheapest easiest to get parts for. you can rebuild it with parts off the shelf of walmart... hahaha
I"ve got a 50 shoebox that I'm building and struggling with the same issue. I'm leaning towards a 305 HO with bigger 1.94/1.60 valves, some monor porting, and a mild cam. Then either a 5spd of 700r4
I've got some variant of the belly ****on motor in my car and it gets around just fine, it also can chirp the tires in 2nd gear.
My 49 is subframed with a 70 nova clip and I just got done with the motor mounts for the 500. I had a 302 with an aod and it was ok, but im almost trippleing the horsepower and torque with the caddy. Planning to run 2.75 gears out back. A merc is not all that heavy of a car I've had mine on a scale with the smallblock it only weighs 3005 lbs... Thats mustang weight. I'm dealing with The cad company here in Albuquerque. They are building the engine now 380 HP 600 and some Torque = 3400 bucks yea its expensive but the engine is awesome. With 2.75 gears my tires were figureing 19 to 22 highway and 14 to 17 in town.... High 12's to lo 13's if I can get it to hook up at all....... TORQUE oh yea