I need to know how reliable a Flathead V8 is.... I'm taking an approximately 145 mile trip @ 55-60 MPH its an off frame Restored 1936 Ford Pickup with about 800ish miles since the build. I'm trying to weigh out my options so I don't have to trailer it... I believe It still has the original gearing and drivetrain but fresh.. I'm unsure about the year of the engine and HP rating but it moves fairly well and tops out around 70mph... I'm leaving in three days so any good advice would be appreciated I just Installed the Tach and took it for a short drive... 2500 RPM The 50 MPH 2800 RPM @ 55 MPH 3200 RPM @ 60 MPH How are these numbers for the trip?? Its a .030 over bore and .010 X .010 Shaft Grind The Temp stays fairly consistant @ 140... and on 100++ degree days 160.
Remove the tach, and drive. If it sounds sweet its Ok Ive got 4,11 in the rear and at 80mph it starts overheating. but i can go 70mph all day Dont worry
Given the numbers you've given here, I wouldn't even consider driving it 145 miles at over 4000 RPM; that is almost the maximum revs on a stock flathead . Since you seem not to know a lot about that particular engine, I wouldn't even consider it. All respects to the second poster, but I think he's giving you some bad advice.
It has a .030 over bore and a .010 X .010 Shaft Grind... ill go through my sheets and see what else I can find...
If the engine is a fresh build with 800 miles, I will back off a little; from your original post, it seemed that you were unsure of what the engine is. I still wouldn't do it, though.
Thanks, Ill just throw her on the trailer then... Im going to be selling it so I know I dont want to screw anything up.
I took off 2 years ago in my 40 with a worn out 8BA that I had only driven 30 miles since the 70's drove Tulsa to Austin about 9 hours each way and drove it another couple of hundred miles around Austin for three days and never had an issue. 3.78 gears 6.00 rear tires 55 t0 60 all day, don't know the rpm? it was 30 degrees when I left Tulsa and 90+ every day the rest of the trip. Yours is new, I would say drive it. sounds like you have 4.11's though, taller rear tires would help!
I'm on the fence right now... I might just do it but stay at about 50, might take longer but would save me the hassle of a trailer and 2 trucks...
When you get back from your trip you may want to gear it up some. I just got a GPS and now can tell how fast i,m going. I,m running 2.78 gears and 2000 rpms is 55 mph.
If you plan to run that bad boy on the road once you get it home, stick a rebuilt Columbia or new Mitchell OD unit under it. Just sayin'
Those RPM's sound like the 5.13 gears in old Jeeps. What rear end gearing do that year truck have stock. Probably 4.11 ish? RPM's at 60 should be 3000-3200 or so. Try another tach..............
This subject has been debated (beat?) to death on this and other sites. 3500-4500 is WAY too fast to twist that engine for any more than short spurts. Even 3000 for extended periods is pushing it. When Ford built over-the-road trucks (1 1/2-2 ton)they were governed to around 2500 (2800 max). You need to seriously consider changing to at least a 3.78 gear if you want to enjoy that truck. A 3.54 would be even better.
Just drive it at a speed that feels comfortable. 145 miles isn't that far - even at 50mph it'll only be 3 hours. When you drive at a comfortable speed, you'll enjoy the journey and be able to look around and see the scenery. Make the trip a pleasure drive, and not something that just has to be done and got over with as fast as possible. If it tops out at 70 mph that would be 5000 rpm plus according to your tach. I would say the tach is not reading right. Are you sure the tach is not set to 6 cylinder? Your truck probably has a 4.11 gear. I'd go with Lars, disregard the tach, drive at a comfortable speed and enjoy the ride. Mart.
That's what I was thinking - are you sure the tach was connected properly? Rear gears and tire size have more to do with roadability than what the engine is. Take it easy, learn to listen to the engine - it will tell you what it likes. Have a good time!
Do you think any of these cars and or motors would still be around after 50- 60 - 70 years if they couldn’t go 150 miles? Drive that V8 Ford
This is good advise....enjoy your ride, and what is the hurry...if traveling with friends, they shouldn't mind slowing down for that short distance !! One of my friends has a '32 HiBoy and we slow to ~45-50 mph for him, as it bounces all over the place any faster... ENJOY, Cheers...
the best way to save a flathead is a coolant recovery tank you can run it pretty hot as long as you can keep water in it what broke the flatheads was pukeing water out and steam at the top cracked the block. ive run mine for years at 210 degrees and no problems when i pulled it no cracks dont run it over 2200-2300 rpm you will be fine
Don't beat on it...55mph....maybe 60mph....no more than that....no need to wind the old girl any higher than that....anything more than 60mph is just needless and preventable wear and tear on your engine...what's the hurry anyway??...you wanna go fast??...drive your OT daily driver.
You have an edge your engine is worn, or loose. A tight flaty doesn't not want to do extended periods of high rev cruising. Actually no tight engine wants to do extended periods of high rev cruising, that is why we set up our performance engines on the loose side of tolerance. To the OP, if your truck is stock you own a 45 MPH vehicle, it should be driven as such for extended periods. Old trucks were not intended to go fast in stock configuration, they were meant to go to town and get a sack of feed or supplies for the month then go home and toodle around the farm. You shold be able to cruise in the 45-50 MPH range all day long and occaisionally get up a little faster to pass someone, yea right.
The cruising sweet spot on both of mine seems to be about 2200 rpms but I think you would be safe for extended periods as long as you stayed under 2800 or so. I road trip mine regularly I changed the final drive ratio to 3.00 in one and 3.12 in the other.
Think also about the roads that were about in 1936. The big fast moving freeways where you can do 70 plus all day did not exist. You need to set your mind back to the 30's and drive accordingly. Nowadays people modify their cars with overdrives and taller axles to travel more like a modern car, but the old stock ones are still very capable if driven at a speed appropriate to their age. Mart.
In the early to mid '30s my grandad used to drive the old caddy from Wamic, Oregon, to Los Angeles California every year. Took 5 days each way, now it can be done in 17 hours. No one said they didn't go far they just didn't go fast.
X2, you dont have to take freeways. Take backroads and enjoy the ride. Who knows, you might even spot some tin along the way.
Flat head V8 are very reliable. They use to run 100000. miles with no problem. You can drive them any speed you wish. They were not babied back in the day. The biggest problem was vapor lock on real hot days. Most of the time it was from a worn fuel pump push rod. The other thing was cracks from the cylinder wall to the exhaust valve. That was some times caused by a bad radiator, and adding cold water. They have a very good crank and bearings. And I'm a chev man, so I'm not just making them look good. I worked on all kinds of cars in my Dads garage, plus we rebuilt engines, back in the day.
Thanks Mart, I compleatly forgot to change the switch in the back to the Tach ... It is set to 6 cyl. Ill give it another shot and see what I come up with.
You could consider a decent tranny? We put a T5 in our roadster and the stock '49 flattie turns about 2,000 RPM at 60 MPH, about 2,300 RPM at 70 MPH. The rear is a '48 with 4:11 gears I'm thinking. Rolling at 60 MPH is about cruzin speed for us - any faster and it can get kinda scarry with the bias tires and all. Take that tool box and hit the road for a nice slow trip!
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