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416 sm block stroker & rod ratio?

Posted By: ragtop

416 sm block stroker & rod ratio? - 05/29/09 02:50 AM

Does the short 1.53 rod ratio have a noticable negative effect on cylinder side loading, the faster piston speed at top and bottom dead center, and the less dwell time at top dead center? Thanks.
Posted By: RapidRobert

Re: 416 sm block stroker & rod ratio? - 05/29/09 03:13 AM

I read up on it as I was contemplating going that route & yes(from what I gathered) that the 4" crank reduces the rod/stroke ratio almost to the point of the side loading being an issue but there was a long thread on stroking them & every one to a person said that after stroking their 340/360 that with the added street manners from the torque increase that they would never go back to using a stock stroke SB
Posted By: cudasam

Re: 416 sm block stroker & rod ratio? - 05/29/09 03:32 AM

I love my 406 Magnum. It feels like a strong 440, and the car handles nice with the weight reduction up front.
Posted By: goldmember

Re: 416 sm block stroker & rod ratio? - 05/29/09 03:39 AM

There is no free lunch. For a low RPM street/strip combo the added CID is a big plus. The small head CSA(not including exotics) keeps the RPMs and HP down. Last year we had a cylinder wall fail in a mild mid 10 second street/strip car(J heads). That went 2 years with the 4" crank,it went 25years and 9yrs on the track with the stock stroke. Not very scientific test,but I disasembled a 408" street/strip shortblock today and the pistons look like they have 100,000 miles although it's closer to 10,000 miles.
Posted By: cudasam

Re: 416 sm block stroker & rod ratio? - 05/31/09 03:23 AM

A lot of Harleys have a similar rod ratio, and I have 32000 on mine with zero problems. And this motor is air-cooled !!! I can't see it being an issue in a V8.
Posted By: RapidRobert

Re: 416 sm block stroker & rod ratio? - 05/31/09 04:58 AM

Goldmember. I have a 360/408 on paper & I have some badger .020 cast pistons w .017" clearance in a freshly bored/honed block. If I go with a 4" crank would the tight clearances here minimize the piston problems with this deal? 360/6.123" rods/5/64" rings, Daily driver low rpm
Posted By: Dusted_Ya

Re: 416 sm block stroker & rod ratio? - 05/31/09 05:01 AM

If your wanting reliablility stick with stock ratio's... There is no such thing as ultimate performance AND reliability. Everything has a trade off. Look at women for example Either you want smoken hot or reliable...
Posted By: goldmember

Re: 416 sm block stroker & rod ratio? - 05/31/09 05:13 AM

.017" piston to wall sounds loose to me. It's been many years since I used a cast piston,but I thought you'd want around .002" clearance? I'd stick very close to the piston companys recommendation for clearance. I assume this piston is from another application or has Badger built a piston for this combo. You will need to check for crank counterweight clearance and consider a small deburring of the bottom of the bores to minimize the chance of scuffing. My test above really doesn't prove a thing as old blocks break and even with a stock stroke it can happen.
Posted By: RapidRobert

Re: 416 sm block stroker & rod ratio? - 05/31/09 05:19 AM

My mistake I meant .0017" EDIT I have everything covered except I am wondering about any possible piston/wall problems from the side loading/rocking from the low rod/stroke ratio.
Posted By: goldmember

Re: 416 sm block stroker & rod ratio? - 05/31/09 05:28 AM

I don't see a problem.The rod/stroke ratio doesn't cause any problems and plenty of 454 and 400 chevys seem to verify it's not a big deal.
Posted By: RapidRobert

Re: 416 sm block stroker & rod ratio? - 05/31/09 05:34 AM

Alright, if it is good enough for you it's good enough for me
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