| Tony Radford |
07-09-2003 08:44 AM |
SB Stroker Experts - Comments wanted
My biggest problem is that I'm not smart enough to know what I should and shouldn't worry about with regards to my current project. As most of the english speaking world knows by now, I'm in the process of replacing my 351 with a 427 Windsor stroker. My existing headers are the standard Unique 1 1/2" tube type. I've determined that increasing the tube size will be prohibitively expensive. Are any of you running a similar set up? If so, is the performance adequate? Has anyone upgraded after the fact and experienced the performance enhancement (or not)? I'm stressing.
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| coyled |
07-09-2003 10:31 AM |
Tony, I am not an expert but 1.5 tubes are not big enough for 427 cubes. I would go to at least 1.75. I am running 1.875 to 2.0 step headers on a 358ci motor. 1.5 inch headers will choke that motor in the mid range and high end. Scott
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| Mr.Fixit |
07-09-2003 10:57 AM |
Skinny primaries will hurt top end, but help low end torque. The gains made by having custom headers made may not be worth the $ it costs. You can always have bigger headers made later, if you decide you have too much money and not enough HP.
I have seen a chevy with a 632 cid motor running through 1 7/8" primaries, so much torque it couldn't hook up it's big tires in third gear (3 spd auto, manual valve body) from a standing start.
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| Tony Radford |
07-09-2003 11:20 AM |
Thanks guys. Custom headers look like a challenge with regards to price and inconvenience. Mr. Fixit, that sounds like good advice. Who knows, maybe my weekly lottery ticket investments will pay off.
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| hound dog |
07-09-2003 11:33 AM |
Tony,
Ask Maurice if he'll step the headers for you. You will also have to give him the type head you're using before he makes the headers. Some have raised exhaust ports and that will make a difference on how they're built. Speaking of stroking, I'd have to give it some thought if I were to do it again. There is nothing like the sound of a small block, short stroke engine bringing up the revs. In comparison, my stroker sounds like a John Deere pulling a sod buster (or was that a big block falling all over itself). So many choices, so little time. :p
h dog
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| GeorgiaSnake |
07-09-2003 11:44 AM |
Tony, we need to talk. I can tell and show you what I did with my headers. I was freaked out when I saw the huge ports Bill had provided and the little hole I had in the headers. I spent a weekend with a grinder (carbide) matching my ports as best I could. My motor pulls like a freight train and revs like a banshee. I'll be glad to help you - it ain't hard.
Randy
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| Tony Radford |
07-09-2003 01:02 PM |
HD, I spoke to Alan yesterday (Maurice is out of town) and he talked like it would be the end of the year before I could get a set from Unique. He said that the header fabrication was one of the hardest steps in getting the car kit together.
Randy, I remember you mentioning the port dimension indifference a few weeks ago. Didn't Clyde do the same thing to his? I figured I could probably pay SA to do the work on my header flanges while the engine is out of the car. Were you pretty happy with the outcome?
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| GeorgiaSnake |
07-09-2003 02:51 PM |
Tony I think I took off much more material than Clyde. I matched the height 100 % and increased the sides by as much as possible. I also angled the entire port to get better flow. I'm sure SA can do it.
I can't offer much on the outcome because I never drove it before I made the improvements. It is one strong little motor :3DSMILE: :3DSMILE:
Randy
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| Tony Radford |
07-09-2003 02:58 PM |
Randy, do you have the standard 1 1/2" pipes or the optional 1 3/4" ones?
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| GeorgiaSnake |
07-09-2003 07:32 PM |
Mine are 1 1/2" I've never seen any thing bigger than 1 1/2" on a small block. The limiting factor is the bolts. Some restriction is good for bottom end torque.
Randy
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| chill |
07-11-2003 09:29 PM |
Tony, I think I could actually see through GS' header tube walls....
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| jopper |
07-14-2003 12:47 PM |
I have headers from my old motor that had Windsor SR heads. They have 1 5/8" primaries. The new heads I have are AFR 205's and the ports are much larger as you already know. I was given the name of a guy who is making a new flange with stubs that will fit into my old headers after I cut the old flange off. I think it's a good fix for this problem.
He also said the mid range torque would be better with the smaller primaries.
He is having the flange laser cut and the stubs come welded to it. He's making extras if anyone is interested.
His name is Len Ewell, Boffin Motorsports. PH# 503-624-2659
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| coyled |
07-14-2003 01:17 PM |
Guys, a stock 302 from ford mustang runs 1 1/2 inch headers. Add 40% more cubes, more compression, and better heads. Now, 1 1/2 inch headers defeats the purpose, its like putting a 300 cfm 2 barrel on a 427 motor. 427 ci motors in 2400 pound cars don't lack for low end power even if you run 2 1/8 inch headers. Its the cobination that makes the motor go. Scott
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| Tony Radford |
07-14-2003 01:58 PM |
I contacted an outfit in California that specializes in headers. After giving the stats on my new engine, he came back with an optimum configuration of 1 5/8" at the flange and step up to 1 3/4" to the side pipes. I'm already set up to have this done. I received an email from a guy who's running 2" tubes on his 408 stroker. The original dyno set up is running 1 1/2" tubes and he said the HP was reduced by 97 HP from 620 with the smaller tubes. I feel like I need to make a change.
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| wilf leek |
07-14-2003 02:02 PM |
Tony - see? You wouldn't believe an englishman, would you, but once a few of your countrymen chime in with the same thoughts it becomes "time to make a change". :LOL: :LOL: :LOL:
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| Tony Radford |
07-14-2003 02:11 PM |
Wilf, I'm an extensive world traveler and have many friends around the globe. You are a brother of the cult regardless of which side you mount your steering wheel on. I've received so many views (some conflicting) and had conveniently consigned myself to the thought that I should leave my headers alone and focus on another aspect of the build. But the dyno numbers I got via my personal email were too sobering. In addition, I found a header fabricator that will do the job for half of what I was hearing previously. What can I say? I'm easily confused!
Thanks for the inputs.
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| coyled |
07-14-2003 02:16 PM |
Tony, I think you will be happy with the step tubes and your low end will be plenty also. I run the 1 7/8 to 2 inch steps on a 358ci motor, 660 hp at the crank, 7200 rpm. There is lots of low end power even with the big tubes. Good luck, Scott.
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| Tony Radford |
07-14-2003 02:41 PM |
Scott, what heads are you running. I don't think 1 7/8" pipes would fit between my exhaust manifold bolts. By the way, I like Scottsdale. I built the 7 meter earth station antenna system that sits in the pit behind the Mayo Clinic facility. I spent two weeks in that pit in the heat of the summer. Got a great tan.
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| coyled |
07-16-2003 07:05 AM |
Tony, Yates heads, 115 in phoenix yesterday. Its like a 1930's dust bowl around here. Scott
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