crazy schemes are going on in my head again. I'm thinking I'd like to build a 427 block 428 crank torque monster. What does desktop dyno say for the following:

427 block- 4.25" bore is standard, right? Assuming I cough up the buck for one of the genesis new blocks or the like.

428 Crank- what is the stroke, and can someone explain how this changes with the crank having been turned x amount? Any advice on identifying a 428 crank and what else to watch for?
Edel RPM Intake
EDEL 750 Carb
Edel Aluminum Heads and included CJ sized valves.
Crower Cam currently in possesion:
Cam Specs,
Grind Lobe Center :292H/112D
Advertised Duration (Intake): 292, (Exhaust) : 302
Duration @ 0.50 in. (Intake) : 214, (Exhaust) :224
Gross Lift(1.76/1.76) (Intake): .521", (Exhaust): .547"

Thanks in advance.

 

After I left, I realized some compression values may be needed for the desktop dyno. Use the values that would run best on 93 octane pump gas. Is that about 9:1?

Thanks,

 

standard bore on a 427 is 4.23

 

410 and 428 stroke is 3.98

 

Sorry to keep replying to my own posts, but, I've been looking at the cam you have and am curious how you like it. How's the idle? does it lope? Where is your power at? Thanks

 

The 427 bore .030 over and a 428 crank will give you 454 cubes. Doing a regular grind on a crank will not change the stroke since you just use thicker bearings. You can offset grind the crank quite a bit but I wouldn't. It will weaken the crank and will require custom rods and pistons. Good luck on getting a Genesis block. There are several people that have already sent their money to genesis a year ago and haven't seen their block yet. I do think it will be a great block when it comes out though. Your power peak will be probably at 4,000rpm or so with that cam and that many cubes. I will try and run a desktop dyno for you later if I get a chance to sit down. At work right now.

 

[updated:LAST EDITED ON 27-Sep-02 AT 02:52 AM (EST)]I am a novice tuner and am still tweaking the 390 setup. Right now, it seems a little weak on the low RPM power, but picks up nicely after about 2000rpm. There is mild lope to the idle that I kind of like. It runs up to 6000RPM with the stock valve train (In neutral, I havn't pushed passed 5500RPM in gear yet). I may have too much carb for the stock heads. I originally purchsed the Edelbrock package including the AL heads with better flow and bigger valves and the single pattern Edelbrock Cam. Folks here advised against the single pattern cam and reccomended this Crower among others. I had trouble with the Al head heli-coils upon installation and ended up seding the heads back. One of the guys here is running the same Cam on his 428.

Will a 428 block safely bore to the same as a 427?

 

Nope, the 428's 4.13 bore would require a .100 overbore to get to 427 specs. There are 428's out there that won't even go .060 over. It would be nice though. There is one guy on another forum that claims to have an early 390 block bored that far but that is the only time I have heard of that.

 

I plugged some numbers into Desktop Dyno for you. I had to make some assumptions, including compression ratio. Keep in mind that you may need custom pistons. There are quite a few choices for stock 427 and 428 pistons, but I don't know that anyone stocks pistons for stroked 427s. I assumed that you would use the Edelbrock 76cc 427 heads, small tube headers with mufflers, and would have dished pistons to keep the CR at 9.5:1. Using the cam specs you provided, DD showed peaks of 431 hp at 5500 rpm and 462 lb-ft at 4500.

You could build a 428 or even a 410 that generates that much torque for a whole lot less money (see my Project F-475 thread for details) that a stroked 427. The 427 can be built to deliver a lot more horsepower, however, because a high-torque 410/428 will start to run out of oomph around 3500 rpm and will probably deliver peak horsepower of around 350.

For instance, I'm building a 428 right now (using a 360/390 block that is .080 over). With a 9.5:1 compression ratio and the Crane 343901 cam, Desktop Dyno shows peak torque of 474 at 2500 rpm, with a nice flat 470+ from 2000-3500 before it starts to trail off. Peak horsepower is only 361 at 4500, however. So my 428 should actually pull harder that the 454 you spec'ed up to around 4000 rpm, but above 4000 rpm that 454 will easily outperform the 428.

Of course, you could always go with a milder cam in the 454, which will increase your low end torque substantially at the expense of higher rpm power. Still, the expense of building a 454 ($3-4000 block, $500-1000 custom pistons, etc.) just doesn't seem worthwhile to me. It would be cool, though, so if you have the cash, go for it!

 

Sorry to butt in on this one, and don't get me wrong, I really like my FE engine... But once you talk about spending that much money, you have to ask: "What is the end goal?". It would be cheaper to swap in a 460. Just my 2 cents...

--Matt



1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Soon to have a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

 

Now a 410 is the same bore as my 390 but with the longer stroke of a 428 crank, correct? I guess I Would need to change pistons and rods?

And this 410 combination is pretty good for torque? That's just 20 cubes, is it worth it?

I'm not looking to just throw money away, but would like something that bolts in to my truck and transmission since I've got the rest of the drive-train , suspension and brakes , wheels and tires are up to the task. I've still got to work the power steering. I'm exploring these ideas because I may want the truck to become an occasional big boat tow vehicle.

Thanks for all of the info.

 

Yes, a 410 is a 360/390 that's been stroked with a 428 crankshaft. The advantage of a 410 over a 390 is more than just the additional 20 cubic inches. The longer stroke results in better torque because of the lever effect. Remember that stroke is determined by the distance between the crank main journal centerline, and the rod journal centerline (that distance is the "throw", and stroke is equal to twice the throw). Picture the piston traveling up and down in the cylinder, the crankshaft turning, and the rod connecting them. The longer the throw/stroke, the longer the lever that is applying a rotating force. So the same amount of pressure on the piston results in greater rotational force at the crankshaft if the throw/stroke is longer.

That's why Ford built both a 427 and a 428. The actual difference is displacement between the two was only about 1.5 cubic inches, or three tenths of a percent. The 427, however, was a large-bore/short-stroke engine, whereas the 428 was a small-bore/long-stroke engine. As a result, the 427 didn't develop a lot of torque, but it would spin higher and develop more horsepower, particularly at 4000+ rpm. The 428, on the other hand, developed LOTS of torque from off idle up to 3000 rpm or so, but trails off after that and becomes a dog beyond 5000 rpm or so. The 428 was designed specifically as a torquer to move the very big and heavy cars Ford was building in the late 60s.

a 428 will be more powerful than a 410, but not by a lot. IMNSHO, the extra cost of a 428 block as compared to a 360/390 just ain't worth it. A 410 at .030 over is 416 cid, and at .060 over is 422 cid. That's just five cubes short of a 428.

 

Incidentally, to convert a 390 to a 410, all you really need are pistons, crankshaft and a new flexplate (the 410/428 is externally balanced via a weight on the flexplate). A 410/428 crank runs $200-400 and a new 410/428 flexplate goes for about $50-75. Pistons are all over the board. I'd recommend using Sterling 360/390 truck pistons if you are building a 410. They go for about $100 for the set and are available from Summit and many other places. They'll keep your compression ratio down near 9:1 depending on what heads you have, which is perfect for a tow vehicle.

 

[updated:LAST EDITED ON 27-Sep-02 AT 12:46 PM (EST)]Matt,
I can appreciate what you're saying about the 460. But I laready have a small compliement of FE performance parts, an FE compatible C6 transmission and an FE compatible engine bay and exhaust. Not to mention that I am more familiar with the FE setup since I have owned 2 and never owned a 460/429 series motor. For me, it's worth a few more bucks.

KarlSD- thanks for all of the great info. I'm currently at .020 over and that was a recent rebuild. Sounds like I could get away with the pistons and crank and it would probably be right to get some nice ARP hardware at that point.

Anymore reccomendations for pistons? I'll probably go with Edelbrock heads and would ike to run well on 93 octane pump gas.

Thanks Again

 

Roush racing used to offer a set of pistions for the 454 (427 WITH 428 CRANK). Its been a few years ago sense Ive seen the ad so I dont know if they still have them.
Leadmic