I recently came into posession of a '77 chev 400 motor, small block,looks to be in good shape, can anyone tell me briefly the pros and cons of using this motor instead of a 350?
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I recently came into posession of a '77 chev 400 motor, small block,looks to be in good shape, can anyone tell me briefly the pros and cons of using this motor instead of a 350?
needs external balanced flywheel/harmonic dampner-------if its complete engine everything compatibal---mounts, exhaust, accessories
I have the truck, so it is all there. Flywheel is cracked but that can be replaced easy enough. (motor/trans already removed) I was asking in terms of reliability and what kind of cost comparisons in improving on power. I know most parts are interchangeable but I would think the 350 would have less expensive parts inside as the 350 was produced in much larger quantities. On the other hand I have heard(and read) both good and bad things about the 400. Also, in checking prices it seems the 400's cost quite a bit more if one was to buy a complete motor.
Price of what parts? Doubt there's enough difference in 350 and 400 internals to even make it a consideration. 400 has a longer stroker and makes more torque, probably better for a stock type rebuild for a truck. I'd have to suggest you consider which would provide you the best engine for your application rather then just counting the pennies.......
Some folks don't put much stock in the 400 because of the siamesed cylinder walls, claim they cause heating problems, and the external balance bothers some; the heads are also different, have some extra steam venting holes in them that the 350 heads don't, and it has been said that the 400 heads are prone to cracking. That said, I never had any problems with the 400s I had in my trucks, and I worked them pretty hard; in my experience they are good engines, and given the choice, I would take a 400 over a 350; appropriately massaged, they will make excellent power and be dependable doing it.
400's are horrible,and as a real pal,I'll offer to sacrifice myself by letting you give it to me. I'll put up with drilling steam holes to swap in 350 heads and the horror of using reduced base circle cams to clear the crank. Hank
Reduced base circle cams? By that you mean there are special cams for the 400? I have a retro-fit roller cam for a 350, but if I cant use it then the price of improvement just went up. I have read of cracking problems with the stock heads but I also have some good 350 heads, should I put them on instead? How about you stop beating around the bush?
Hey Pat, can you give me the real story on the 400?
If I didnt have to count pennies I'd be drivin a Ferrari
Check with your cam manufacturer to see if the one you already have will work in a 400. I used early 327 heads and just drilled the steam holes myself. You may not want to increase the compression that much. Quite a few late seventies chevy heads were prone to cracking not just on 400's. Hank
and he didn`t beat around the bush ,,,Quote:
Originally Posted by halftanked
I always thought it was inferior to 350. I always heard just like 400 Mopar is inferior to 383,400 Ford inferior to 390,360 Mopar inferior to 340. I' can't verify 350- 400 but the others are all true lol. That I can verify!!
Comparing a 400 Ford to a 390 Ford is light comparing an apple to an orange! They are 2 different engine designs / families.. The 400, known as a Modified, and the 390 known as the FE. Completely different designs and intended uses.
The 340 / 360 comparison.. I've never heard anyone ever say a 360 was inferior to a 340!
Perhaps it's a regional thing?
I meant when I was looking to buy a late 60's early 70's Ford everybody said make sure you get a late 60's cuz 390 is a lot more durable and has more horsepower. Same when I was looking for a Duster everybody said get a 340 their a lot hotter. That's what I meant not internals and such. We on the same page now?
Oh apples and oranges are both fruit ,round and grow on trees close enough. Its not like comparing an orange to a basketball lol.
If you were raised in a Mopar family like I was you would hear the 383-400 340-360 comparisons often and 400 and 360 would always coome up short. More cubic inches less horsepower does not weigh heavily in their favor...
That is not true that the 390-400 came in different cars with different intentions. IT replaced 390 in all cars LTD,Galaxie,Montego,Marquis etc... I won't go on but it was all of them rest assured.
Thanks, I think I will just scrap the 400 along with the rest of the truck and stick with the 350
FWIW, a few years ago I pulled a 400 out of a wagon and stuck it in a 621/2 ton. I hooked up a 3 speed using a 454 flywheel. When a cam lobe wore out I replaced the cam with a 64 edition Isky 30-30 cam, Offy 360º intake, Holley 650dp and a cheap set of Hedman headers. I used the stock 283 bellhousing with hydraulic clutch and had a 3100lb pressure plate built locally and the best clutch disc they had. My only problem was keeping rear ends under it and at the time it made a few believers out on the street especially a guy in a 455 Bonneville amongst others. Never had a over heating problem running the stock radiator and the clutch fan that came with the engine and no shroud. It pulled a 16 ft camper trailer like it wasn't even there. I quit driving it when I busted a valve spring grabbing a few too many R's. It still sets in my garage and if I ever rebuild it it will go in my 76 Vette, same cam and with a Offy 360º dual quad intake.
double post
DO NOT SCRAP it! Circle track guys will buy it from you and pay decent money for it as long as it is a good core and not cracked. I'd look into that. Keep in mind the 400 crank is used for 383 builds in 350's. You have to have the mains turned down, but it is an option. Don't just scrap it. :LOL:Quote:
Originally Posted by racemaster
Heck no, don't scrap it!!!!! If it is a 509 two bolt main block, it is a good foundation for a nice engine. It would be best if the block can be cleaned up with a .030 overbore. Lots of potential here with this engine. Don't be too concerned with a small base circle cam. The big end of the rods can be clearanced to get around this.
NOooooo!! No, no - don't scrap it! It is very salable, and if you just don't want to bother with it, I need a (looong) day trip, I'll drive over and take it off your hands.
If you are contemplating a rebuild, before you buy any parts, have the block magnafluxed. 400 blocks are more susceptible to cracking than other blocks. It is getting harder and harder to find a good 400 block.
400's used a 5.565" center-to-center connecting rod, which cleared the camshaft lobes. When you build a 400, you would normally use a 5.7" or 6.000" connecting rod because there are more piston choices with those rods. Problem is, these 5.7" and 6.000" rods will interfere with the lobes of the cam. Aftermarket rod makers, such as Scat, make rods that will clear the cam or you can use a cam with a smaller diameter base circle to clear the rods.Quote:
Originally Posted by racemaster
A 400 bored to 406 and with the right cam and a good set of aftermarket aluminum heads will easily make 500 hp. Any head used on a 400 needs to be drilled for steam holes if the motor is to be operated at street rpm's. 400's used for racing would make enough rpm's to keep the steam pockets in the block flushed out without using steam holes in the heads.
Technical Articles at Greg's Engine & Machine
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Before you give up or get too far along, drop by Anderson Machining on 1st street - across from the main NAPA warehouse. Talk to them for the straight skinny on what both rebuilds will take and get an estimate of how much. They also will be able to speak to modifications for more power. Excellent shop with good work ethic.
Stock 400's are torquers! Of the 9 engines I put in my '72 El Camino in 450 thousand miles, two were 400's. They lasted as long as any 350 hand grenade, ans smoked the hides a lot better. Short on RPM, but you can't have everything in this world, I guess.
Well, I pulled a valve cover and everything looked clean. So I pulled the intake and boy howdy, looks like new lifters. Looking down the distributor hole I could see what looked like new bearings. From the other end I could see a double roller chain. At that point I am thinking this motor was recently rebuilt. So I crossed my fingers and put it in the broncamaro. Would not start. Pulled the plugs and two center plugs on driver side came out wet with water in the oil. Started thinking "great, cracked head". So I pulled the one head and the head gasket was ripped, Im guessing during installation. Also some of the head bolts were not torqued. Cylinders still showed cross-hatch. All valves were a bit loose. Had 3 head gaskets hangin on the wall, drilled one for steam holes and put the head back on. Once I got the timing right it started right up. Changed oil and filter. My freinds, I believe this motor has less than 1000 miles.
My offer still stands ---- just in case you get dis-enchanted.
;):3dSMILE::D
Rrumbler, you are welcome anytime.