470 ci build opinion

[m79ded]

Hi

I am getting ready to pull the trigger on a 470 B engine. It's going into a street car that will see limited track use but go to shows and go for like 150 mile trips, and it will be running on manifolds. Reliability and longetivity is important.

I have a 440 steel crank and getting that done by a local machine shop here they will cut mains and counterweights and offset gring it to 3.915.

The choices I have for internals are 6.70 rods with 1.32 comp height pistons or 6.535 rods and 1.48 pistons.

Although the weight of the 6.70 rods with 1.32 is a lighter assembly, I wonder if the piston comp height is not too short.
Will it cause wobble in the bore?? Would the 1.48 comp height pistons be better.

I have noticed a great bunch of talented people on this board that have done alot of builds and would greatly value your opinion

thanks

 

[Cranky]

I like longer rods in my engines but haven't don't the math on your 6.70 rod to see where the pin is located but longer skirts help with piston rock. Short rod engines usually produce more cylinder wall loading thus more friction. That said, I never did understand the reasoning why people want to build strokers and then choke them down with stock type manifolds etc? It's a waste of money imo. I ran a stock stroke 440 in the early 80's that ran 10.60's in a 68 road runner and ran 9.90's with a 470 stroker in a lighter car but both engines were built for it with good breathing heads and large tube headers. You lose a lot of potential building a big engine that's choked down with restricted breathing.....

 

[lewtot184]

usually shorter pistons will run a little tighter clearances. i've built a 470 with 6.8 rods and short pistons with no piston or rod issues. if it were me and driving and reliability were very important i'd do the shorter rod. the piston will be more stable and the shorter rod will help the low and mid-range a little.

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rod ratio differences are 1.71 long rods, 1.66 short; not a big difference.

 

[Garys1969RR]

I built a 451 using 6.76 440 length rods with the 1.32 C/H piston. 3.75 stroke. My pistons ended up at .017" below deck. Have you calculated what the below deck piston clearance is in your build? Just curious. Looks like it is going to be .075" higher with the 3.9 " stroke? Is this going to work ok for you? I like to work out all the math and clearances before hand. This will ensure no surprises later.

 

[m79ded]

I built a 451 using 6.76 440 length rods with the 1.32 C/H piston. 3.75 stroke. My pistons ended up at .017" below deck. Have you calculated what the below deck piston clearance is in your build? Just curious. Looks like it is going to be .075" higher with the 3.9 " stroke? Is this going to work ok for you? I like to work out all the math and clearances before hand. This will ensure no surprises later.

Yes I did check and it would end up at .0025 below deck with 6.70 cheby rods and 3.915 offset grinded crank
I heard great things about a build like yours and maybe that is something to think about.
I particularly took the statement that cranky made to be very realistic. Is it really worth the added efforts expense just to choke it up?? maybe I got blindsided by the F.A.S T cars I saw at drags and wanted a bit more.

I followed your build for a while and you seem to be happy and it's doing well for you.I know it's a easier build to do as well.

I also read some posts and took some valuable info from other members particulatly IQ52,

Thanks

 

[383man]

I agree with Cranky about why you should use good headers to take advantage of the strokers power. I also see the FAST cars run truly crazy numbers through exh manifolds. But dont be fooled by the really fast FAST cars as some are basically high dollar Superstock engs but they build them using the best cam they can to work with the exh manifolds. Sure they could gain power with headers but they would also change their cams. So if you really decide to use manifolds make sure you go with a cam that works best with them as I would have a good cam grinder grind a custom cam if I was using manifolds. Course I dont as I use headers because they make more power as my eng is just a basic mild stroker and I wanted the extra power from headers. I myself could not afford to build a strong FAST eng as they can get very trick. So unless you are going FAST racing I would use headers as thats what we all did back in the 70's. Headers is one of the first things we would put on our muscle cars. Good luck with your 470 build. Ron

 

[lewtot184]

those FAST cars and engines are purpose built; mega money.

 

[rumblefish360]

The fast engines are no different dollor wise than a regular race engine really. Particular attention has to be paid to the cam timing, intake and exhaust. On the rest of the car, attention to the converter on back must be eye balled and thought about!

I like the idea of the FAST catogory. Guys with deep pockets took it over to quickly.
It is sort of a good thing. The bad was it squeezed us empty pocket guys out quickly.
The good part is they showed us how to go quick with using stock parts. Just how capable the parts really are and what careful thought can do. I have long been telling people that the (small block) stock intake is a capable part. Leave the Performer or the LD-340/Action Plus alone. For what most people are doing, they could have saved the money for a better cam.

But back to the topic at hand.....

I myself would save the money on building the 470 and do a 440/451 since stock manifolds are to be employed. There is really no sense on adding the extra cubes. While most of the power gain will be in torque, I find it hard to see the 440 or a 451 short on torque for a street or mild street strip car.

 

[HT413]

But back to the topic at hand.....

I myself would save the money on building the 470 and do a 440/451 since stock manifolds are to be employed. There is really no sense on adding the extra cubes. While most of the power gain will be in torque, I find it hard to see the 440 or a 451 short on torque for a street or mild street strip car.

the biggest question - what is the budget? for me, i'm building a 451 (that i JUST picked up) and it was always about the biggest bang for the buck. the 470 is 19ci larger, or 4%, so it will have about 4% more capability. find out the additional cost for that 4% and figure out if it's a wise decision or should you invest it in some heads?

first consideration is the condition of your parts. you have the crank, but does it need machining, or are the journals ready to run in a 440 block? if they just need a polish, buy a 440 block and build it. also, look at the rest of the build - what parts do you already own that you plan on running? iron heads, mild intake, 750 carb, mechanical fuel pump, stock-ish fuel line, etc? all that has to be replaced on a stroker.

do you have the 400 block? if so, does the block need machining? if you don't have the block, smart money buys a 440, gets the crank ready to run and spends the extra coin on heads. if you have the block, but it needs machining, sell it and buy the 440 block. the 440 will be cheaper, so you profit on the sale of the more expensive 400 block, plus you save on lots of machining of that crank. all that goes into heads.

if you have the crank and it looks like hell, dont waste money machining mains, rod journals and counterweights to get to a 470. for probably the same $$ you can buy an aftermarket crank and build a 500-512 beast. don't forget that you're buying rods and pistons anyway, so including the cost of the crank machining, you're 90% of the way to a stroker kit.

however, if you do build a 500ci + beast, you now MUST invest in major fuel system upgrades as well as heads or you've wasted your money.

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and THAT was my best impression of budnicks.

 

[m79ded]

The fast engines are no different dollor wise than a regular race engine really. Particular attention has to be paid to the cam timing, intake and exhaust. On the rest of the car, attention to the converter on back must be eye balled and thought about!

I like the idea of the FAST catogory. Guys with deep pockets took it over to quickly.
It is sort of a good thing. The bad was it squeezed us empty pocket guys out quickly.
The good part is they showed us how to go quick with using stock parts. Just how capable the parts really are and what careful thought can do. I have long been telling people that the (small block) stock intake is a capable part. Leave the Performer or the LD-340/Action Plus alone. For what most people are doing, they could have saved the money for a better cam.

But back to the topic at hand.....

I myself would save the money on building the 470 and do a 440/451 since stock manifolds are to be employed. There is really no sense on adding the extra cubes. While most of the power gain will be in torque, I find it hard to see the 440 or a 451 short on torque for a street or mild street strip car.

Thanks very much for the advice, you and a few other knowledgeable people here have mentioned the same thing.Since i'm running through manifolds, extra cubes might be a headache. I really do want to stay with manifolds because they are virtually maintenance free. The car I own is a black version of your Dodge Magnum avitar so it's heavy and needs torque. Although the 440 engine in it now is very tired I was going to do up anothe engine and just do a swap over the week-end. And I have experienced headaches from a stroker engine with manifolds, about 23 years ago I put a welded crank 4.15 version in that car with manifolds and 9.5 comp and it would not stop pinging it literally almost rattled to death. I then put on headers just to try it out and all the pinging went away even with the thermoquad which is still on it and a cast iron intake it managed a 11.60 119mph. I stupidly took out that engine after 3 weeks of use and sold it and put in the present engine. So I did want to get a bit more out of it but quickly come to realize that choking more cubes might get me in trouble again. Well it was a fun ride back then.

 

[HT413]

If you are set on the manifolds... how about saving the stroker $$ and investing on some of the technology the FAST guys invest in. Like extrude honing the exhaust and intake manifolds for better flow? Just sayin.

 

[383man]

I like what the FAST cars have done also and I agree the real fast ones have pushed the little guy out from running with the big boys. But from what they say you can still race in the FAST class if you run 10's or 14's. Course the quicker cars get all the limelite.

That said I would use some of their tricks when you can like the extrude hone manifolds and all. But remember on cubic inches the FAST cars are running alot of cubes as thats helping them make their power and torque and the big cubes eats up the sound of the huge cams they run as the rules say they SHOULD sound close to stock !! I stress the word SHOULD as thats a tuff rule to enforce. But my point is they run alot of cubic inches as thats one of their secrets also.
Also I was going to mention this because you said you like exh manifolds because they are basically maintance free. Well my TTI headers are the same as when I put them on with the eng going in the car in 2011 I have not touched them since and they have never leaked. They have thick flanges about 1/4 or close and they will not warp like old headers of the 70's. I mean mine have been great and I have not touched my exh system since I put my 63 together in June 2011. I have driven it a ton all the time and raced it a bit over the last 3 years . I have never uncapped my car because I have never touched the exh as I race capped up. My point is if you decide to go to headers the good modern headers like TTI are basically maintance free also. Just something to keep in mind if you decide to go with headers but you may have your mind set on manifolds and I understand if you do. I know when I decide I want to do something one way then thats what I do if my mind is made up. Anyway just wanted to drop this in here and I wish the best of luck with your build and you know everyone here will help all we can. Ron

 

[m79ded]

Hi Ron

Thanks for the advise and yes I will strongly look at those TTI headers. You aren't the 1st to say that they are good and much better than those 70's headers.Also like I mentioned before there are a great bunch of people here that are very knowledgeble and eager to help out. And because I had a negative experience with a 493 ci corked up I was kind of gunshy and asked for opinions.So I figured a 470 might not be as bad as the 493 was. BTW you have a very nice car and very well setup.

 

[Garys1969RR]

Start with good flowing alum heads such as Eddy RPMs , or Stealth. That's where you will get the most torque and horse power, all other things being the same. And as 413 pointed out, 4% more cubes isn't much considering the extra effort. The beauty of the 451 build in my opinion is: 1- the 400 block is more rigid, with more strength in the main webs than the 440 block. 2-can use stock 440 crank and rods which are still plentiful, and plenty strong. 3-the 1.320 C/H of the 451 piston makes it much lighter than a 440 piston with C/H of 2.08 or whatever it is. And the 451 piston will end up at .017" below deck. Thats just right. 4-the 400 block lower deck height allows more room in the engine compartment. I.E. for header clearance and ease of spark plug access.

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I have had no noticeable probs with the 1.320 C/H pistons. The motor is running better each year. After 3 years of racing the 1/4 mile at 5600 feet, have gone from 13.40 at 100 MPH, in 2012 with stock ex manifolds and 906 heads, to a best this summer of 12.32 @ 110 MPH. This with ported 915s, larger valves, headers, and a street fighter torque converter. Oh, and I threw in a stock 727 from a low mileage 68 Polara 383 motor.

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Have been running the old reliable .509 cam with the original stamped steel rocker arms, from the beginning till now.

 

[383man]

Hi Ron

Thanks for the advise and yes I will strongly look at those TTI headers. You aren't the 1st to say that they are good and much better than those 70's headers.Also like I mentioned before there are a great bunch of people here that are very knowledgeble and eager to help out. And because I had a negative experience with a 493 ci corked up I was kind of gunshy and asked for opinions.So I figured a 470 might not be as bad as the 493 was. BTW you have a very nice car and very well setup.

Thank you for the kind words. I do run my 493 capped up on the full exh system as actually I have never uncapped it. Ron

 

[wyrmrider]

Yes I did check and it would end up at .0025 below deck with 6.70 cheby rods and 3.915 offset grinded crank

closed chamber heads will give you some quench at that of 0.0 deck
what compression are you shooting for?

 

[m79ded]

Yes I did check and it would end up at .0025 below deck with 6.70 cheby rods and 3.915 offset grinded crank

closed chamber heads will give you some quench at that of 0.0 deck
what compression are you shooting for?

I am shooting for about 9.5 due to pump gas available. I did find a good match on pistons from Diamond 1.32 comp height and 13cc dish.Should work great. or I can go with same pistons with 3.75 crank and stock 440 rods to make up the 451 which is much more cost effective. And like a few members pointed out 451 will do well. The extra 19 cubes vs $$$$$$$ spent ????????? might be a better idea to throw $$$$$$$$$$$ in heads.

 

[wyrmrider]

I am shooting for about 9.5 due to pump gas available. I did find a good match on pistons from Diamond 1.32 comp height and 13cc dish.Should work great. or I can go with same pistons with 3.75 crank and stock 440 rods to make up the 451 which is much more cost effective. And like a few members pointed out 451 will do well. The extra 19 cubes vs $$$$$$$ spent ????????? might be a better idea to throw $$$$$$$$$$$ in heads.

another option but for your cr wishes you need a larger dish
https://www.uempistons.com/index.ph...id=375&zenid=d8f202404700fc73f9bfb71ac8101da2
see the cr chart by clicking on piston image and scroll down

 

[m79ded]

another option but for your cr wishes you need a larger dish
https://www.uempistons.com/index.ph...id=375&zenid=d8f202404700fc73f9bfb71ac8101da2
see the cr chart by clicking on piston image and scroll down

That would work as well,the only drawback is that it's about 150 grams heavier than either the Ross or Diamond pistons and the price is comparable.

 

[wyrmrider]

That would work as well,the only drawback is that it's about 150 grams heavier than either the Ross or Diamond pistons and the price is comparable.

but irrelevant as he needs a bigger dish to get the compression he wants
keep looking I just used for the CR chart