302ci, or 302ci Long rod?

[Thomas302]

Hey guys, I just wanted to know if someone could explain to me the differance between a standard 302, and a long rod 302. What would be the benefit of building a long rod motor? Is the complete rotating assembaly different, or just the rods. If it is all different, it probably would be better to just build a stroker. Just curious, I have a friend thinking of building a long rod motor. Thanks.

 

[what_stanger?]

the long rod keeps the piston at TDC longer and BDC longer doesn't it?
increases piston dwell?

at least i bumped ya.

 

[dastang2]

i never heard of one

 

[hllon4whls]

There are some HP advantages to a long rod motor. But those can be overcome with a stroker.

 

[thumper460]

Wit the cost of stroker kits now a days... stroking is better and just a littl more expensive! the Longer rod on the 302s will make about 15-20 HP over a stock rod 302. Before all the aftermarket rods hit the markets the trick was to use a 289 rod ( which is longer than the 302 rod) and then cut .060-.065 off the top of the 302 piston, for the correct compression height!! Or an aftermarket rod and pistons... and there the cost comes in.. Stroke IT!! My self?? anyone ask what size engine...?? I look them in the eyes and answer...302, Why?? LOL

Just me...................

Thumper

 

[Michael Yount]

Thumper - I tell 'em it's a 260.

Here's an article that explains the differences pros/cons of bigger and smaller rod/stroke ratios. By the way - it's not a tradeoff without repercussions. While a longer rod motor (all else equal) is better at filling the cylinders at higher rpm, the shorter rod motor is better at filling them at low to moderate engine speeds. So low end torque is better in the shorter rod motor - think about that for street applications.

To answer the question - the rod and piston has to changed/altered. When you increase the rod length, if you don't alter piston height, or get a piston with a relocated pin, the piston will hit the head when it reaches tdc. Well, it actually won't reach tdc. At least not without making some very expensive noise.

http://www.victorylibrary.com/mopar/rod-tech-c.htm

 

[Thomas302]

Thanks guys, that was some good info.