destroke 454?

the13thround · Newbie Joined: 04 Mar 2007 Posts: 12 577.06 points

i was wondering if anyone has done this and if so was it worthwhile?
like a 427 crank in a 454? just juggling ideas around because in need a new crank. the rod to stroke ratio is much better on the 396/427 motors.

Hanz · Posted: Wed Mar 07, 2007 12:23 am Post subject:

If you put a 427 crank in a 454 block, you get ...a 427

You don't go with a shorter stroke to get a better ratio, you go with a longer rod...but have never heard of any problem with the stock rod length in a 454...
Hanz

the13thround · Newbie Joined: 04 Mar 2007 Posts: 12 577.06 points

well the 427 has a 1.63 ratio while the 454 has a 1.53 with the same rods.
i looked into it and generally everyone seems to think that its not worth it except for race motors, which makes sense but has anyone done it and posted results like e.t. or dyno graphs?

Hanz · Posted: Wed Mar 07, 2007 6:37 am Post subject:

Done what, compared a 427 to a 454, or compare different rod lengths in the same ci motor and dyno?

If its the latter, I have looked for hours and asked that same question, with no results. I have marked it on my 'to do list' someday when I have the time and money. lol

Hanz

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

I have posted about this before. Rod ratios dont seem to make any differance on the dyno. The only thing that matters is weight, and the shorter rod is lighter, the lighter the rotating assembly the more power it will make period. All this stuff about dwell at TDC and such is crap as far as power. At 8000 rpm the dwell isnt going to matter. Just advance the timing and get the burn started sooner if your worried about dwell.

Hanz · Posted: Wed Mar 07, 2007 11:23 am Post subject:

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

Actually mine is 17.2 to 1 LOL. Dont get me wrong, I think a good ratio is good for the street and engine life. As far as timing I am talking 1 degree. My personal experience is my engine has a sweet spot where it likes to be timed and no matter what the altitude, changing the timing slows it down. The only thing I do is maybe a air bleed change if the air is terrible to lean it out a little. One of my engines is decked so low that we had to install studs with set screws in the top water pump bolt holes so the studs could be decked (the deck goes into those bolt holes) I was still able to run a stock length rod with a light weight piston and a tapered wrist pin to net 1700 grams which is pretty light for 500 C.I. I dont know where this post is going, just a subject that hopefully will be interesting.

Big Dave · Posted: Wed Mar 07, 2007 3:46 pm Post subject:

If we are talking a race motor I favor the 427 all the way. If were talking a pump gas street motor I’d go with the 454, or if looking for a new crank the 4.25" which nets you a 496. The 496 makes a very good street motor, especially with the round port heads and a matching hydraulic roller that will make use of any valve and bowl work.

I have run a number of 13:1 BBC 427 engines with solid rollers, some on the street, but mostly for weekend’s night time entertainment in my youth. To take advantage of this combo you need stiff gears and decent suspension. It also isn’t the most economical engine I have ever made with my last motor averaging half a mile to the gallon of Sunoco 260. Course gas was cheaper and I was still living at home, so that wasn’t what I built it for.

Big Dave

alfonsothefons · Posted: Wed Mar 07, 2007 6:51 pm Post subject:

knarley what kind of alky and nitro mix are you running with that 17.2-1 compression is it injected? Surprised

what is it in?

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

67 camaro true 10.5 tire car, stock suspension, floors, and fire wall. Normally asperated(Two 1150s). I run VP c-16

af2 · Posted: Wed Mar 07, 2007 10:27 pm Post subject:

alfonsothefons · Posted: Thu Mar 08, 2007 3:15 pm Post subject:

so it is a pro stock style motor 500ci. set up?

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

alfonsothefons · Posted: Thu Mar 08, 2007 3:38 pm Post subject:

back to topic what is the purpose of destroking except higher rpm's and extending the powerband range,is that what you are looking for?

the13thround · Newbie Joined: 04 Mar 2007 Posts: 12 577.06 points

i don't know i was just wondering if anyone had numbers or dyno graphs? i guess im just curious like a cat. my friends call me whiskers. anyways im planning on just doing a stroker 496.
it seems like a good all around engine and its been done before so i shouldn't have trouble getting info on the setup, being that this is the first big block i've ever built.