427 stroker small block the good and the bad please

[big_rob]

im looking at the 427 small blocks, it seems to me boring and stroking a 351 out to a 427 might be a little scary (paper thin walls).

i like the idea of keeping the 427 number under the hood but are they as reliable as the famous bored and stroked 408's

[Perf. Eng. Eric]

You can use a Dart block with a 4.125 bore and install a 4 inch stroke crank and its a bullet proof 427. Add some AFR 205 heads and a hydralic roller cam with .600 lift and you have 600 hp and its very driveable. Hope this helps.

[blykins]

The cubic inches in most cases doesn't come from the cylinder overbore...it's from the stroke. Most stroker kits are used with .030" overbore. The displacement comes mainly from the crank stroke.

It also depends on the vintage of the block you're using....80's and 90's blocks aren't cast as thick as the 60's and 70's blocks. The older blocks can be bored quite a bit. I have a D9 (1979) block...and it's bored .060" over. No problems.

As with any stroker, piston travel is increased. This could cause premature ring wear...but I'd say you'd really have to put the miles on the engine to see it. Also, with radical stroker kits, the rods are so long and the piston compression heights are so short, that the oil ring is moved to fit around the wrist pin bore. You can usually get around this (I did with a 425ci stroker)...but sometimes you can't help it.

The pro's? Gobs and gobs of horsepower and torque. There is no replacement for displacement.

The con's? I myself can't really find any on an engine that is to be used in a weekend car. If you install this in your everyday driver, it would be extreme. But these cars are toys.

Some of the engine builders even offer these engines with fuel injection. I'd say they're very reliable and tame.

Now you mentioned the 393's, 408's, and 418's. What you're dealing with there is a stroker with a little shorter rod than a 427W. What that brings is a higher peak horsepower....they like to rev a little. My 425ci engine peaked at 5400 with the torque peaking at 4500. So you're getting some of that increased piston speed back by the fact that you really don't have to rev it to get the power out of it.

Hope this helps.

[goaztecs]

I have a 1969 351W that's bored .030 over with under 10K on a total rebuild. Are you saying I could just replace the bottom end (pull out the crank assembly) and replace with a stroker assembly (crank, rods, pistons, rings), bolt back together and go? Assumes I like my heads, cam, carb, manifold. Or is a complete rebuild in order?

[blykins]

You could just change the rotating assembly, sure.....Of course certain engine will like a certain combo of parts...i.e. heads, intake, carb, etc. However, upgrading to a stroker is definitely do-able.

You can just order the whole rotating assembly already balanced, and bolt it in. On long stroke kits, you may have to clearance the cylinder skirts on the block to keep everything from hitting each other. No big deal though. Just call up a reputable parts shop, tell them what components you have, and you could have a kit specially made for you. They will have to know what heads you have so they can get the right compression and valve cuts in the pistons. Also, you'll need to know how your flywheel and harmonic balancer are balanced so you can get a good total balance on the assembly.

The only thing is that if you have 10000 miles on an engine, more than likely there may be a little wear in the cylinders. The cylinders may need to be cleaned up to make sure the rings will make a good seal.

[Tony Radford]

I had to go with the 427 stroker. My previous engine was a stock stroke 351 that made a little over 400 HP. My new stroker is so much more powerful. Waaaayyyy more fun! Go for the max. Just use top of the line components. Southern Automotive here in Atlanta set mine up and did a great job.

[powerpagers]

Hey;
I got an 83 windsor from Cleveland Stroked up 427,plenty of room left after 30 over. No worries.
PP

[Hal Copple]

i have about 70,000 or more miles on my 393 stroker, about a thousand race course laps. Runs the same oil pressure as new, and compression is even on all 8 cylinders, doesn't smoke, or use oil.

How good can it get.

[blykins]

Hey Hal,

At what rpm does your engine make all its power?

[DC COBRA]

I have 427 aluminum windsr from Keith Craft. Dart block with 4.125 standard bore. This motor is totally street friendly with 10.5 comp, hydraulic roller, made 615 tq at 4900rpm, 612 hp at 5700 rpm and carried 594 hp to 6800 rpm. this motor weighs close to 375 pounds. Haven,t got to drive car with this motor yet, real close to completion. I am sure it will be a learning expierence with clinched butt, white knuckles, non removable chek to cheek smile.

DON

[big_rob]

what costs can i expect when building a 427 stroker and what short cuts (if any) can i take.

[big_rob]

i see them on ebay for around $4000 is this a good deal???

[Streetwize]

I know of no real bottom end problems if you start with a good sonic checked and well machined block. As for quirks, well once the stoke gets in the 4.125-4.17 range, you should be real careful with rod to cam clearence, you want to allow .060" minimum clearance up there, you have to allow for chain stretch, I use a reduced base circle cam along with the quiet Gear drive on long arm motors.

The other thing to consider if upgrading from a 351 is that you need a lot more Airflow out of the heads, I look for a minimum of 280 cfm @.500" valve lift to insure the motor will rev in the 5500 and up range.

You'll love the all-over power and wall top wall torque. To me it's the best of both worlds to have big block power and small block weight.

Also, Please strongly consider a scattershield when running a stick behind a torque monster motor like these. An exploded clutch will cut through a cobra body like a hot knife through butter and the flywheel is about even with your calf (not your ankle) in most Cobras.

[big_rob]

a shattered clutch huh, sounds like you had a scary experience yourself. but, good to know. i will consider a shatterhield .
Where do i find one and the aprox. cost would be apprecated
thanks
big rob

[Streetwize]

For small blocks they are fairly common in the 5.0 racing world. Lakewood is the best known mfg of Scattershields. Look in a summit or Jegs catalog. I think the cost is in the $300 range, I bought mine used from a 5.0 racer who switched to an automatic in his drag car.

No personal horror stories, but I've seen the aftermath of a clutch explosion several times. There is a thick motor plate and a bell housing, they are steel and SFI certified. They add a little weight vs a cast aluminum bell housing but with the close proximity in a cobra I won't even ride as a passenger in a strong motored car that doesn't have one. An exploded flywheel has enough momentum to sever your leg in a split second. At least the scattershield's weight is in the back of the motor and in a Cobra it's where it can actually help the CG and f/r bias.

[gsharapa]

I love mine and it is very streetable. The key is a good engine builder and a combination of bore and stroke. If you try to do it with to big of stroke it won't last. Get yourself a block like a Ford Racing W block, Dart etc that you can take out to .060 or .125 and you'll be fine. Call Keith Craft at Keith Craft Racing and he'll be glad to answer any of your questions..............