428 Cobra Jet stroker help

jmlay71 said:

http://www.network54.com/Forum/74182

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Agreed, and they are going to tell you a .60 over 428 block needs a sonic check.

Keith Craft has all the stuff you could need to stroke it.

Dove is a real popular company with bb Fords.

the 428 already has a 4" stroke. youre going to need a lot of strengthening if you want to take a 4"+ crank up to 6000 rpm (splayed main caps, strong conecting arms, etc.)
i would spend my money on ways to make the 428 more efficient, not more displacement.

Well, you can't put splayed maincaps on a 428. Pro-Gram Engineering does make some cross bolt caps that you can retro fit a 428 or a 390 though. Dave Shoe is making a Cap Saddle that ties the center 3 mains together, he made it primarily for N02 applications on a FE. The Scat stroker kits (4.125" and 4.25") come with better rods, although there's not much wrong with the stock rods at 6,000 rpm, but they won't work well with the kit. I know it's 6.7" rods with the 4.25" stroke and I think 6.8" with the 4.125" stroke. Several companies are stocking pistons for these Scat cranks in flat top and dished pistons, Diamond being one of them. In addition to Dove and Edelbrock for aluminum heads, Shelby ($$$), Robert Pond and Blue Thunder make aluminum heads and there may be another head or two out this next year. Shelby, Dove, Pond and Webber Mfg. (Genesis) all make aftermarket blocks as well with the latter 2 making iron ones in addition to all of them making aluminum ones.

You seem a little touchy today, Tim.

With good heads and a decent cam, 500hp at the flywheel is not out of the question at all.

Tim: I feel your pain. I have a 390 block thats .030 now and will not bore to .060 . The shop said .040 is pushing acouple cylinders. So I ordered a Scat stroker kit to go in it at .040 . I feel like its throwing good money after bad. But if it blows it blows...lol...I also went with a solid lifter cam to keep the rpm's down. It was a roller to start with. I'm not sure how much stress is going to be on the lower end of the block? But that is what worries me more than anything else at this point. I thought about doing the 4 bolt mains. But the price of those and the machine shop work to make them fit, sonic check and bore is 2/3 of what a new 4 bolt block cost. So if it lasts maybe next year I can swap blocks out. Here's a photo of the stroker kit.
Bud

bud4660 said:

Tim: I feel your pain. I have a 390 block thats .030 now and will not bore to .060 . The shop said .040 is pushing acouple cylinders. So I ordered a Scat stroker kit to go in it at .040 . I feel like its throwing good money after bad. But if it blows it blows...lol...I also went with a solid lifter cam to keep the rpm's down. It was a roller to start with. I'm not sure how much stress is going to be on the lower end of the block? But that is what worries me more than anything else at this point. I thought about doing the 4 bolt mains. But the price of those and the machine shop work to make them fit, sonic check and bore is 2/3 of what a new 4 bolt block cost. So if it lasts maybe next year I can swap blocks out. Here's a photo of the stroker kit.
Bud

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Damn that's pretty!! That's what my 308 wants to be when it grows up! Plus a little sqeeze

10secgoal said:

Damn that's pretty!! That's what my 308 wants to be when it grows up! Plus a little sqeeze

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Thanks!!! But thats not the pretty stuff. This is the pretty stuff here. I figured if it dont run fast it can look good sitting still......

Ok, Ok that's pretty, too. But a stock BB can look like that. Hehe,but it ain't gonna move like a stocker !! That's what gets my rocks off.

10secgoal said:

Ok, Ok that's pretty, too. But a stock BB can look like that. Hehe,but it ain't gonna move like a stocker !! That's what gets my rocks off.

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What you talking bout??? It is stock. It just gonna thump hard.....

You should see the Ported 428 CJ heads thats going on it.....lol

Tim, I'm not knocking your purchase, heck, I'm jealous!!! I've got a 390 that's .060 over now that I'm hoping to take to .080" over for a stock bore 428 and still have .125" walls. There's a test you can do on your block called a drill bit test. You take the shank of a drill bit (part that goes into the chuck) and after you've pulled the freeze plugs, find the largest bit that will still fit between the bores on the cylinders. Go from the top all the way to the bottom and do it in between the cylinders at all 6 freeze plugs. If memory serves, your looking for a bit smaller than 13/64's (a search on the FE forum should yeild the right numbers, particularly look for posts by Dave Shoe on the subject, "drill bit test" is the search I believe), anyway, you know the bit size and the bore spacing and bore size, math will give you the thickness of the two walls together. Mind you, a sonic check is necessary to determine core shif and this is on the non thrust surfaces, but it will give you an idea.

I agree with both the drill bit test and paying to have it sonic checked, but having had numerous FE's including 428's and having worked in a Core dept of a large foundry, I personally have NEVER seen a 428 last long past .060. The core shift on some of these motors( especially 68-70) is truly nasty. That being said I do wish you the best.

man I can barely afford to put a new (meaning used but better) intake and carb on my 289 and there is a thread about stroking a 428....

USU_Stang said:

man I can barely afford to put a new (meaning used but better) intake and carb on my 289 and there is a thread about stroking a 428....

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Thats where the old saying "you got to pay to play" comes from. My deal was one that I had been thinking about for years. And this is my last one. I have built and raced and sold a bunch of cars in the last 30+ years. And at 50 this is the last one. I found the right one and said I'm going to build it the way I want. Money is the only limit. I dont want to soak a 100k into it. But it looks like its going to end up around 40k by the time its painted. I have averaged a thousand a month into this thing until 6 weeks ago. I have had the car one year Nov 29. In the last six weeks I have spent almost 10k to build this motor and I thinks thats cheap from what I've seen. The trannys next. That looks like $3,500-4,000 for one that will last. Now it will probably take 3 years to pay it all off. But what else I have to do...