402 BBC Stroker

Hey guys,

The Navy is getting ready to deploy me in a couple of weeks and with the extra money I'm going to make, I figured it's a good time to buy parts for my 72 Monte Carlo. My question is this. I want to stroke my 402 out to a 427 and I am unsure of what parts I need to do it. I know I need a 4.00" or 4.125" crank. I am assuming a crank from a 454 will work. Will my stock 6.135(?)rods work or do I need different rods. Do I buy pistons for my 402 or are there some special ones I need specific to this application. I have also read about long rod and short rod strokers, are there any specific advantages to each? Swapping with a 454 engine is out of the question because mine is VIN stamped and all original down to the alternator and starter. I figure this is the only way to build the most power out of it with the stock heads. I'm looking to get in to the high 11's low 12's. If there is anything you guys can recommend on a reasonable budget it would be greatly appreciated. Thanks again guys. Later

The Wolf
Chief Petty Officer, United States Navy


Register now (free) or login to remove ads

You might try taking a look at www.speedtalk.com in the general tech section. This exact build is being dicussed including pros and cons and including part #'s for the pistons.

Thanks for the link. It seems most people are against it, but I'm going for it any way. I can't gather why it would be a bad build. No replacement for displacement, and this is the only way I'm going to get a bigger motor without losing the the original block. A lot of folks are quick to talk smack about "little" big blocks, but when you are trying to keep it numbers matching you do what you have to do.Thanks again.

The Wolf

a 427 and a 395/402 have the same stroke. The 427 has more bore. A 454 has the same bore as the 427 but another 1/4" of stroke.

There are stoker kits for the 396/402 that use 454 cranks. Makes around a 440 cid.

as you already know, a 454 would be better, as it can easily be bored to a 470 cid, or stroked to 496 cid. But you seem determined to stroke the 402. 440 is better than a 402, that is for sure.

Why don't you use a 454 and bolt all the original accesories on it? Then you can store the original motor original. Remember you can only rebuild them a few times and if it gets fouled up your original block is going to be junk.

What ship are you on?
I hitched a ride on the USS Truman on its maiden voyage when I was in the Marine Corps.

Your backing up, the small bore long stroke combos don't make much power the small bore shrouds the valves too much. They used to ues this type of setup in boats 4 3/8" stroke and 4.250 bore. I have bored a few of them (bowtie blocks) to 4.500" to build a 557 and they came to life.

I would not blow money on that setup.

Thanks again for the replies. I'm deploying with the USS Bataan. I'm a stubborn SOB so it looks like I am going to go for it anyway. I could store the block, but it has never been rebuilt so hopefully it has a few more left in it. If it's done right it will only need one. I still can't understand the disadvantages of this combo. More cubic inches should result in more power or am I better off just building my 402? I have seen and owed a kick butt 396 that put my 72 Camaro into the mid 11's. I didn't build the motor, but it was wicked. Like i said I'm just trying to get the most power out of it using the original block. Thanks again.

The Wolf

Think of a 366 same stroke as yours but a smaller bore. They make good torque but no power.

Now think of a 509 4" stroke and a 4.5" bore, mine made 822 HP big bore short stroke BBC's make the best power.

I agree with you.

Just stroke the engine you have, and install whatever camshaft grind you want. Do whatever you want to the heads, and 'gear' it to your engines final horsepower range.

I realy cant see the point, if you like matching numbers I dont anderstand why you wold risk blowing the orginal engine upp, if you punch a hole in you block you culd never make the car matching number agen...If you after most performanc four the buck, it wont cost mutch more (maby less) to build 454.I like the stock look tho, I wold have bult al the stock accesories to a suped up 454, paint the alu intake (if you youse one) Chevy orange and juse the stock air clener whith 402 sticker on it

here is a stroker 396/402 with a 454 crank.

http://www.classictrucks.com/tech/0...uild/index.html

good torque but the hp is on the low side.

I would lean toward aftermarker parts and building a 454. As said earlier if you start poking hole in the 402 its value is depleted

USS Bataan, that's cool, are you going out with a group, im a PO in the navy and stationded out at Oceana NAS, i dont know of any groups going out in the next few weeks, i know that the IKE and wing 7 went out in late Feb, you can definalty tell that im in the aviation side, cause i couldn't tell you squat about the surface side, good luck, what cruise are you doing

im not much on all original resto's but if you want more power everyone is right, go to the 454, it will cost just as much to do but in the end you will actually have 2 motors (if you keep the 402) and the car wouldn't have lost any value casue if you plan on selling it (this is the only reason for oem resto's IMO is to sell it) then you could still put that 402 back in (make sure you store it properly) and then you will still have a 454 you can put in the next car that you want to drive

Thanks for all the replies fellows. To answer your question I am out of Little Creek, stationed at Assualt Craft Unit 4. We are part of the 22nd Marine Exp. Unit. We'll see how it goes. After reading the previous post I may lean towards another motor. The bulid that was posted was kinda of disapointing. I know a 396/402 is capable of more than 375 or so horse power. Like I said before my last big block ran mid 11's in a 72 Camaro with under 400 ci, so we will see. Take care guys and remember " The men and women of the United States Military, we defend your right to ****** !!


The Wolf

ah fraiter gator, good luck i hope the time goes by quickly for you

yea i would like to know what top end that 396/402 was built with cause i would think i should make a lot better than those #'s, remember that your 72 camaro was a lot lighter than the monte carlo i believe around a 1000lbs, it will take another 100hp/tq (est.) from a motor to do what your camaro did
i will still go with the 454 and save the 402