I did not mean to come off as saying the Tri-Ys are the only good choice there will be applications where the available quads will work better, the list of those applications is just narrower than most want to believe.
As far as the CNCing your heads my point was Stan's headers basically stole Clear Image's work, it was the stealing that was my point.

I understand your point about core shift and such which would pose more of a problem with CNC than it does hand work but fell this statement was at best misleading and an attempt at marketting.

CNC can reduce manhours BUT the big key is consistency, not that hand porting can not be consistent but it will not deliver the level of dimensional repeatablility CNC. They are not cheap machines and take time and a fair number of parts to go through them before you begin saving money. We are going through this at work now. The CNC will help us stay more accurate in our work and will get one particular guy out of a tedious job that carries some risk to digits, the payoff is going to be slow though, the company owner is willing to spend money to make it but the payoff on this piece of equipment has him a little shy and in less of a hurry than usual. And no this will not be a suitable machine for head work or really anything automotive so think I am trying to work and angle there.

 

I did not take your commenst in any way of being favorable towards the 1 5/8 headers. I was just making conversation. I did not realize that these 1 5/8 headfers were that nice of a header. When you think of a 1 5/8 header, you usually think of "less power", that is all. I was commenting on the fact that I would think a 1 3/4 header is better for this set up and your comment opened my mind that these are not the typical 1 5/8 headers like for a F body and they might be a better performing piece than I was expecting.

If you measure everything and it ends up the same size, it doesn';t matter if it is done by hand or machine.

Like I mentioned, core shift will make you go conservative on certain areas to keep from welsing and as long as the CNC actually touched the port everywhere, the measurements are the same. If you are getting areas that are left "as cast", they will measure differetly than one that gets the CNC machine to "touch" everywhere. If you are not willing to wled up a few sets, you will have to make the CNC port job more conservative to keep from having to weld up these areas and the result will be either smaller dimentions in these areas or some areas that are left "as cast". It could be .100" or .001" from being touched by the CNC cutter so this can actually make a CNC port alot less consistant than hand porting. "IF" the CNC cutter can touch all of the walls through out the port, they will be the same size as the digitized head that was "hand ported".

Lloyd Elliott
972-617-5671
Eportworks.com

 

uncorrected?

 

corrected, and backed up with my 11 sec timeslip

 

I think 1000 bucks for a set of headers is robbery, Stan sold me my tri-y's coated with gaskets bolts hook-ups etc,etc for 600 bucks shipped. Heck he even gave me a couple shirts and called to make sure ups delivered on time and again to make sure the install went smooth.

It is not my place to decided on who stole what or to take sides, i shoped around and got a good deal.

 

Thou dost deal a great deal in assumption Dwayne. You know what they say about assumption right?

BTW, what are the fastest b-bodies out there running as far as headers go?

I'm not going to knock a tri-y. The headers I'm using now are a 4-2-1, just with much longer primaries than your typical "Thorley" looking try-y.

-Mindgame

 

Let's see, the Combination Motorsports blown 383 9.86@136 car is running custom 1.875" tubes. The Miami nitrous 391cid 9.98@140 car was running 1.75" 4 into 1s. The 10.12@134 turbo car is running turbo headers (size wasn't given.) The Alabama nitrous 415cid 10.29@131 car is running the same as the Miami nitrous car. The gutted nitrous 383 10.31@134 cop car is running 1.75" 4 into 1s from the guy that does the Tri-Ys. Several of the others in the Top 10 are running 1.75" 4 into 1s also.

 

Ah hmmm...Works everytime....

You got that boat in to the 11's with no N2O! Damn.... Now that's real impressive.....

 

These are brand new cam cores and are ground by Comp just like any CC306, CC503 etc... probably the same core as the GM 847 as well.

As for header tube sizing, the more power you are pushing thru the motor the more header it needs. I don't care what the best average header is for a typical car, but when you put more power thru them than the average guy you can very well be hurting the setup and not have the optimum power for it. The setup was also designed for a 1 3/4" header so I would imagine it would improve the performance as well.

Bret

 

Anderson is running Burns tri-y on his Pro Stock and there for a while he was hard to outrun.
Think it had to do with the headers?

I have run them on SBF and they work. Takes a while to get the merge collector sorted out,though.

 

Well he out ET's everyone... not really MPH anymore. So they all found the HP he had but he's getting down the track faster so it's something.

For a while I think it was more gear and RPM due to improved valvetrain, now I think he might have something else. Hell if I was him I would have the lowest inertia setup I could get, that would get you down the track quicker with the same power, especially in the low gears.

Bre

 

There's a lot to recommend 4>2>1 (Tri-Y) headers on a 90 * (vs. 180 * "flat") crank V8 like our engines. You can separate the two adjacent cylinders on the same bank that fire 90 deg. apart like 5 & 7 on a std. SBC or 4 and 2 on a 4-7 swap. If you let 5 & 7 dump into the same collector 90* apart, the dumb exhaust thinks it's one big cylinder firing so it can screw up tuning and perhaps the flow.

If you just need top end power, 4>1 might be better, but perhaps not. If you need a broader, fatter torque curve, correctly designed 4>2>1 can get you there. Often they lose nothing on the top end to 4>1s. That sounds good for a "whale" like the Imp.

F1 V-10s generally have a firing order that treats the engine like two inline fives, just as a flat crank treats a V8 as two inline fours as far as exhaust tuning is concerned.

 

More torque in the mid range.
He did extensive dyno time with those headers and I think he found something in the merge collectors.
The headers ya can see and everybody has gone to them. The inside cone in the merge collector ya can't see and maybe he's found something.Burns won't say but he gives ya small hints.
I know those headers will work on a 408CI SBF to the tune of .23 in the quarter. Like I said it took more than a few passes to get the merge collectors right(close).

 

I bet I know-- Carbon Fiber Crank-- huh???


Hey,is it snowing up there yet? Sleeting and raining here and 53*.

 

Lloyd - what do you think of John C (Handyman) running his 1 5/8" Tri Y's with the LE2 h/c package and the new 355" - you think he'll be ok keeping these?