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Crossbolting 428 mains.....
Hello everyone! I am building a 428CJ engine for my cobra replica and have a few questions about crossbolting main caps. First am I better off finding original ones or does anyone know anything about the billet steel ones pro-gram eng offers. The block I am using is a NOS service block. It has extra webbing on main caps and is ribbed outside. Bought it new in the original box wrapped in plastic. Its very nice and could not pass it up! Engine will have 500 hp to start and I want the option of doing more without worry to bottom end. Finally is there anything to upgrade oiling through block. I see that southern automotive upgrades oiling on 390-428 blocks. Is this partally done by a pressure relief on back of block? What else.... thanks for all your help. G.
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To start, go to your nearest book store and buy/order, Steve Christ, How to rebuild your big block Ford. No experience with Pro-Gram??.
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FFR428,
You can put crossbolts in if you want them. It is NOT a home builder job as it requires machining not only the inside, but the outside and making spacers for each side of each main cap. Personally, I wouldn't bother and here is the reason: The 428 is not a high rpm engine like a 427...even if it has been built for extra performance. 5,500-6,000 rpm is plenty for it. With that in mind, a well prepared crank and rods, along with some attention to "detailing" the existing oil passages, will handle what you will likely subject the engine to. Not to rain on your parade, but 500hp from a 428 is not going to be a very driveable engine, not to mention a lot harder to get than one might think. That will take a lot of compression (12:1 or more) and a VERY aggressive camshaft, along with serious cylinder head/intake mods and race prepared carburetion. In reality, if you get it to make 400 REAL hp, you will have more than enough to give you the ride of a lifetime and still be able to use pump gas and drive it on the street. Don't let all of the "hp numbers" you read on this site throw you. A lot of it is "book numbers" or just wishful thinking and isn't based on reality. Great find on the block! They're getting pretty scarce. Enjoy your build. Al |
Thank you! Perry that was the first book I purchased a very good source to have. Al thanks for your reply. I fully understand the HP rate varies person to person. Car is not really being built to be a street car more of a weekend warrior thing at local tracks where I can get in to run the snot out of it! That is why I was looking into crossbolting mains. I know rpm's will exaust at around the 6000 range with cam I'm using. Can't really push it too much more. I have a mint CJ crank and lemans rods for bottom end. How do you think it will hold up without crossbolts? G.
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428's
FFR428,
The pro-gram stuff is suppose to be nice. The caps are made with plenty of extra length on the 'nibs' to allow for fitting and maching. You can probably find a good pair of 427 caps and save a few bucks. I think the pro-grams are about 100 apiece. I recently had Bill Parham of Southern Automotive cross-bolt one of my 428 race blocks and it came out real nice. I've got to disagree with Al on a couple of things. For a high-horse 428 that's going to see some track action, I think cross-bolting is a good idea. I've personally seen and heard of plenty of 428 blocks spitting from the mains to the cam journals. The cross-bolting cures this problem plus you get the '427' look. Also, cross-bolting keeps the main caps from 'dancing' at high rpm. It's not the high rpms that kill the blocks, it's the torque the engine is producing. I also think that 500 HP is totaly attainable with a properly prepared 428. I've been running NHRA stock class for over ten years and am actually amazed at the HP that can be squeezed out of these engines. We run factory carb, cast iron intake, unported heads, 0.525 lift cam factory dish style pistons (10.6:1), etc and the car runs 10.50's @ 125 MPH carrying 3400 LBS. Just my 2 sents. Rusty |
I have a set for you
I was going to go that route too until Turk shamed me into spending $20k on a side oiler. The good news for you is I have a never resized set of cross bolt main caps from a 427.. If you want them and are serious you should also have the machine shop put in a set of threaded core plugs.
I have a set of mains and a complete set of steel core plugs you can have for $180. + shipping Regards, |
Main Caps
IF FFR428 does not want the caps and plugs, I'll take them!
Rusty |
450-500.. no problem
I think 500 is obtainable pretty easily if you are serious about it. Hot Rod built a not so far from stock 390 in the Dec. 2002 issue and got 455 HP on their dyno.
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Rusty 2211 What cam are you running? What is the factor hp in your class? Is this a roller cam? What chip is the red line for your MSD? I have a CNC 452 FE motor and heads Alum with a 513-533 cam retarded at 4 degrees and make 348hp 427tork on a chassic dyno. What is your Tork numbers? I would like to know. Rick Lake
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428
Rick,
I run a flat tappet Crane cam that has a max lift of .526/526 @ the valve per NHRA rules. The duration is somewhere around 248/256 @ 50. I say somewhere because the guy I buy my cams from does all the dyno testing and he grinds the numbers off the cam. He just tells me where to put them in the motor (usually 106-107 range). I run about 215# on the seat and 415# open and I'm able to do this because I run Shubeck lifters. The factor in the class I run is 375 HP so you take 375 x 8.5 + 170 LBS for the driver and you come up with 3355 Min weight. I shift the car @ 6600 and in good air cross the traps @ about 7300 RPM. The engine is making about 550 ft-lbs @ the flywheel. Rusty |
Talk to George!
You need to talk to George at Gessford Racing. I could not recommend a better source for work or information on your motor. Look at his site, I believe he talks about cross bolting a 428. If your going to do it, it should be done right the first time. George will make sure of this.
http://www.gessford.com/cobraparts/fords.htm |
Crossbolting a 428
FFR428,
A lot depends on what sustained rpm you are going to run!! Is this car meant for the track, or is it mainly a street car? If it's primarily a street car that will only see occasional and quick bursts up to 6500 rpm, precise blueprinting on the mains and rods along with main studs will suffice. You get a far superior clamping force on the main caps with the fine thread of the stud. This cuts down on cap walk quite a bit if held under 6500 rpm. By the way, I can get 519hp out of a 428 with 9.9 to 1 compression, Edelbrock heads, 850 carb, and a hyd roller cam with only 236 at .050 duration. Tecnology has come along way since the 70's. |
FE Specialties
FE Specialties,
What is the lift on your cam, and are the heads stock like Edelbrock sends them complete with valves. |
Le Mans rods
At the risk of sounding like a heathen, I would suggest that you might wish to rethink the use of the Le Mans rods. In 1965, they were certainly the be-all and end-all of the rod world. In 2003, there is much better equipment on the market. After putting all of that money and effort into your engine, it would be a shame to see it scattered all over the track because a 38 year old piece of critical equipment proved to be insufficient for the task. The rods available in most high-performance factory cars are superior to the Le Mans rods; the aftermarket racing stuff much better than even that. If you are going to be flogging the car on the drag strip, this is not an area upon which to scrimp. My $0.02.
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