409 pistons

[wecenter]

Has anyone ever used the 6.135 bbc rods ina 409/340 hp engine with any sucess.I understand it moves the piston up in the cylinder 125 thousands .Is there enough clearance for the head and will the top ring be up too high in the cylinder.Of coarse the whole rotating assembly would have to be rebalanced.

 

[CDNpontiac409guy]

It's done daily, wecenter... but you REQUIRE a special piston with the relocated pin hole. A factory piston will not acommodate the modification.

I know that if I'm building an engine with fresh bores, I prefer to use the BBC rods ( but NOT Scatno1: ).

 

[Impalaguru]

I'm doing exactly what you're planning, wecenter! I got my pistons from the first responder to this thread!!. Aubrey won't steer you wrong.

Whats the deal with SCAT rods? Are they made out of recycled Yugos or something?
Ross

 

[models916]

I used Eagle

Here is a pic of the Eagle BBC rod. About $250, good to 700 HP. This is the rod I used in my 348 block/409 crank build.

 

[bobs409]

Whats the deal with SCAT rods? Are they made out of recycled Yugos or something?
Ross

Great line!

 

[wecenter]

Trouble is I already purchased a set of good used Ross forged pistons .030 oversize.Another question.I have a 409 truck rod here and a car rod.The car rod seems to have heavier ribs on it.Is that correct or are my tired old eyes decieving me?

 

[wecenter]

I have a truck rod and a car rod here and it looks like the car rod has thicker ribs.Are they heavier

 

[jim_ss409]

I thought the car and truck rods were the same, but I could be wrong about that. I remember Curt Harvey telling me that the pin end of the stock rods can sometimes get stretched out of round if the engine has been over reved.
The Ross pistons are lighter than the stock TRW's so there would be less stress on the rods. But I know for myself I like having good rods because I've been known to blow a shift from time to time.no1: Maybe Eagle or one of the other rod supliers makes a 6" rod. But maybe not because most everybody wants to go with longer rods these days. The rod to stroke ratio on the 409 is very good though, about 1.72 I think. The main advantage of the big block rods is that they are beefier.

 

[Ronnie Russell]

wecenter, I realize I am in a tiny minority that believes there is nothing wrong with a 409 rod. I have used many by re-sizing and installin ARP bolts and have never experience rod failure. Are they strong as big block rods? NO Are they as strong as Eagles? No way. But how much is strong enough? If I were building a street 409 for myself today, I would use 409 rods, especially if I had a set of good forged 409 pistons to use. Its all about the money.

 

[Impalaguru]

I have to agree with Ronnie. I'm going with the BBC rods mainly just because its basically free torque. Probably not much but it might make a little difference. I wouldn't have had a problem using my original rods again. For me, this was kinda one of those "might as well" mods.

Now, I'm a little scared about the rods I got from Summit. They were Summit brand I-beams. ARP bolts, bushed, and all the other stuff they like to brag about with aftermarket rods. I'm kinda thinkin' about returning them and getting some Eagles. There is a place here in town that has them on the shelf. I'm begining to think that the extra $$$ is worth my peace of mind. What do you guys think?

Ross

 

[models916]

resized stock

every time you resize the big end on the stock rod it gets that much shorter. You loose the quench area and horsepower. Would have to deck the block to get it back.

 

[Ronnie Russell]

Mike, Dont see the problem. "Everytime you re-size"?? How many times can you rebuild the same motor. One rebuild should last a life time. If not, that is what mock-up is for, to see how the parts relate. More often than not, the block has already been decked and the problem is opposite of "being in the hole". I have had to shave pistons on the last 3 motors. Anyway , I still maintain 409 rods are sufficient for a street 409.

 

[Mr Goodwrench]

916 is correct but sheee's I've resized hundreds of rods and never had to cut more than 2 or 3 thousdths off the rod and cap, besides if you measure a stock rod, any stock rod they are never all exactly the same length, and if that worries you wait till you gring a stock crankshaft I've seen the stroke very as much as .020 from one journal to the next, centers can be off that much too. If you want to index a stock crankshaft it was very common to have to take the rod journals to .030-.040 under when .010 would have cleaned them up just fine.

 

[models916]

fussy i guess

I must be too fussy about this stuff. Goes back to my Drag race days. Every HP for whatever cost. Besides, I think I drive harder on the street nowadays than I ever did on the strip.

 

[Ronnie Russell]

Models, Could never fault a guy for being too fussy about hp. My problem is having to weigh hp versus dollars. Rods that are in our current stroker in our race car are GM rods I picked from a core supplier bin and purchased for $2 apiece. Re-sized and ARP bolts. Just completed 3 years of racing. New motor that i am finishing has Eagle rods. My partners money. It is much easier to build a motor with someone elses money. The Lamar Walden pedestal rockers are gonna work out nice, but are they worth $800? Not to me, but they are to my partner. A wise old machinist I was talking to recently , that has much experience with exotic stroker motors said, "you can ask 6 machinists a question and get 6 different answers." Guess that is what makes these discussions interesting. Different opinions, different ways of doing things.

 

[models916]

Partner?

Why didn't I ever think of that? A partner with money. Hey Ron, What's your partners phone number?

 

[Ronnie Russell]

Models, My partners name is Barry Taylor. We built the car in Barrys garage over a period of 5 yrs. Raced as a partnership for 5 yrs , then 3 yrs ago I sold the car to Barry. He kept my name on the car because 1. I build the engine 2. We are best friends 3. I work for free Barry believes in using only the best parts available , hence all the "good stuff" going into new motor. Every now and then I have to remind him of the $2 rods in the current motor that have over 600 runs. He always changes the subject quickly. My apology to wecenter for wandering off the subject, however Im sure he got the answers he needed.

 

[raymar58409]

Ronnie, I've got a need for someone that works for free. I'll put your name on the car. Maybe even throw you a sandwich and chips every so often.And a beer at least once a week.bang
Ray

 

[Ronnie Russell]

Thanks Ray for the offer. Better hang around here, besides , Barry buys me a full 6-pack every Friday.