Forum for discussion of MG and MGB motorsports, historic and current (SCCA, NASA, VARA, etc) car preparation, engine, bodywork, suspension, drivetrain modification.
Where's a good place to get a set of MGB race headers, I remember years ago, someone telling me that Kirk Racing made a nice 3 into 1 race header, that was pretty much like the Huffaker 3 into 1, I notice on thier website they list a header for a MGB, anyone running one of those, got a review on the product or any other suggestions?
Kirk makes a great header just as you describe. Make sure you ask for the race version as I believe it differs from his street version. I think he also offers a couple of tube sizes. I would also get it coated by someone it would last a long time.
Hap,
Dave Headley also offers a 3 into 1 header.
http://www.fast-mg.com/index.htm
There's a site from Down Under that offers a header that looks interesting, wondering if any of the Aussie guys are familiar with this company?
http://www.hi-flow.com/HPEH2.htm
Steve
Steve64B Wrote:
Hap:
Your friend John Targett sells racing headers. I don't know much about them, but he usually has good stuff.
Bob
JBRITCARS@aol.com
He used to have a website, but it was hacked by some idiot.
Thanks, for the info guys, I was asking for Fred McConnell, he got one on order today form Kirk. Speaking of David Headley, he's at Topeka, KS for the week for the SCCA runoffs, he recoreded a slow 2:.01 yesterday and no time today in EP, he must be having problems, He's ran real good all year long in EP with his MGB, I sure hope he gets it fixed and gets a good qualifying lap in.
Hap:
I'm also considering a Maniflow LCB header. I was told the 3-into-1 header would be better for top end (and higher revving motors), the LCB better for torque?
Rick
Hap,
Joe Huffaker was generous to give me the specs for his late 70s, 3 into one headers, for my vintage Elva. I would rather not post them on the web. You can reach me at my new web address (I have changed jobs after 20 years!) AByrnes@swst.com
Bud Byrnes
Does anyone have any experience with Burns?
http://www.burnsstainless.com/MergeCollectors/mergecollectors.html
I have a PECO header and the fabrication is terrible. I know the trade off in dollars for power is small, but the workmanship on the Burns parts is incredible!
Steve
Burns Stainless in Costa Mesa makes the finest collector I've ever seen. When my 3-into-1 arrived, I set it on the kitchen counter with the 1 side up and the 3 tubes down. My wife came home, picked it up reverentially and asked, "What kind of religious artifact is this?" Just the collector made us completely re-jet the car and change duration on the cam (shorter exhaust, less overlap, better fuel filling...) Great stuff and prices to match.
Rick, LCB vs 3 into 1, wow that's like asking somebody whats the better tire Hoosier or Goodyear. I don't think I ever ran a LCB race header in my past, always 3 into 1s, so not alot of knowledge about the LCB on my end. When the fancy tunnel exhaust first came out for the Midget, they were all 3 into 1s, then a few years later someone introduced a LCB version and it was all the rage. On my vintage Midget, I'm going to do a tunnel exahust, but one on the cheap that I've seen a few other guys do, they take a Mini header, and with a few careful cuts and pipe direction changes you can make a fairly reasonable tunnel exhaust system,, this header is a LCB design, so it would be my first use of a LCB, for the price, I just have to try it.
Long Center Branch. The thought is that because the middle exhaust port is siamese that it needs a longer runner.
Ah, so, here are some examples of different headers...they all look like LCB's though only the black one is a 3-into-1...am I wrong?
though only the black one is a 3-into-1...am I wrong?
Right, Tony.
The problem with production run headers, (Pacesetter etc. ) is they are not equal length and the collectors are primitive and have the wrong angle of merge. The LCB tube diameters are usually all the same size. They'r fine for street cars tho. A really nice header with a $500 price wont sell in that market.
3 > 1 do work better in the upper rpm ranges.
For street use certainly the LCB has better street drivability and works better at low rpm. But there is some "adjustability' in both designs as the builder can juggle the primary and secondary tube lengths.
As to collectors take a look at the pix of the collector in Steves post above. Note the goilet in the center which promotes air flow. The slip fit entry rings that accept the same o.d. primary pipes and the interior of the collector has no bumps or bends. The merge angle of the tubes. is very small...(unlike the street headers you show in your post). This is a four into one collector but is typical of nice work. Burns gets $200 just for a steel tube 3>1 collector and $250 in stainless. It takes me maybe 5 hours to make one..but my time is worth nothing .
Vizards A motor book has some interesting reading about lengths and tube diameters, and is applicable even today, 20 years later. The tube location in the mounting flanges to the heads has changed over the years from his book....but thats mostly more modern cylinder head exhaust port methodology.
Hap, this one's for you ;)
Come on guys, have none of you Engineers designed something in Solid Works or Pro-E, then run Computational Fluid Dynamic Software to determine optimal flow conditions using MatLab or some other mathmatics softwar factoring in length, diameters and bend radiuses? PLEASE tell me I am not the only one!!! I know you did it before you had someone else make yours Basil, BTW how many headers have you seen? What is the biggest hp difference you have seen trying all this exhaust stuff? WHo has actually done this kind of testing in the last couple of years? (this is typically where no on ever responds to this thread ever again)
Teq
Teq Wrote:
Basil Adams Wrote:
Michael, Indeed you know better. The modeling of the headers (equal length) takes into account pulse timing and evacuation to obviate the need for the LCB. Scattered cam timing can help too.The important part of header design is the thermal retention of the system ( when there's less heat transfer to the material of the header, the gasses stay hot and contract less so velocity stays high) - which is why ceramic coating is so important - and then the appropriate placement of steps in the tubes to match exhaust velocity to the collector moment - you want the pulse from #1 hitting the collector to help accelerate the blowdown of #3, etc... The merge collector placement is critical and tuned lengths and steps are easily modeled if you know your exhaust temperature (EGTs help), your target rpms, and your exhaust orifice and expected cylinder pressure. Burns helped compute all of that. Huffaker built my headers and his calcs were almost identical to Burns' optimal numbers. We had to cut less than an inch off of each tube when we went to the venturi collector.
As for hp attributed directly to exhaust, I've never seen the numbers our friend Craig said he got. But his tiny exhaust port head (which Hap hates) really does make a significant difference. I've put a few of them away :-)
Oh Basil, remember me stating that I knew of guys running pretty high compression ratio number with flat top pistons in a MGB SCCA race car, well there ya go, Michael run a flat top MGB motor at 14.2 to 1. Michael have long "motorhead" phone conversations from time, to time, in fact we had one this week, Michael has a very creative mind, and for sure thinks outside the box, which always make for interesting converstaion anytime we have time to talk.
R&D is some pretty neat stuff if you can afford it, most can't, so most of us buy what's available.
I keep meaning to get a picture of my longtime racing buddy Barry Perkins exhaust on his FP MGB, it's pretty wild, crosses over the top of the transmission and goes down the right side of the tranny tunnel, I never seen anything like it ever before, it for sure is a piece of artwork, but then his whole car is.
I have done extensive testing on the dyno and have fabricated seval sets of headers that have been tested in the last few years in possibly 7 dyno sessions with possibly 5 sets of headers. I have paid ~$70/hour for dyno time and spent a great deal of money on mandrel bent tubing along with the time to tig weld them together. Sorry, I am not giving anything away Steve. I have been tutored by the best, several national champions and "old timers" that know much more than I. I am trying to learn and grow. I have spent a great deal of time learning "how it was done" by people much greater than I will ever be. I am now taking it to the next level. I am discussing with a local CNC cylinder head shop doing some CNC milling of cylinder heads, intake manifolds and Carbs.
It seems I clearly did not make my point in my first post: Basil suggested that one header contact was "Burns Stainless in Costa Mesa makes the finest collector I've ever seen". You have seen how many?Many people respect Basil. I do. I have also seen beautifull headers that flow like crap on the dyno.
My point was, and is:
Is it honestly the opinion that the developement of the B can not be bettered from the 70's with todays high tech tools, or do we just keep saying "well so and so did it" with out knowing why or even if it is good?
I hear ya Teq, R&D is game talked about by many and actually played by a very few, keep playing :)
Teq Wrote:
I've felt the need for a better header system for awhile, it just seems like everything off the shelf is junk. It's good to see somebody is trying to push the limits.
Merge collectors are no magic, Jere Stahl says 1-2HP max on a 700 HP V-8 is standard over a good conventional collector.
I think there will always be a lot of cut and try with headers and all the top people in the header business usually confirm that statement.
Sean
Merge collectors are a bigger deal on a siamese port head than on a 700hp, crossflow Sean, really. But that's not just because of the collector - it's because you can reduce the exhaust cam duration and reduce overlap so you fill the chamber more efficiently.
Teq Wrote:
I agree with you Basil about fuel distribution and the cam possibilities, but it relates to the big picture and weak links. This thread, about race headers, is one of them.
There are CNC mandrel tubing benders that from CAD designs, bent tube and then I weld them together. I know that in 1970 they did not do this.
A realy cool thing I enjoy when it happens, is when something is done with "gut feelings" by the old timers. Then, I waist a ton of time doing research, and conclude that:
1) Changing the one thing does not make any significant difference (more than 5%)
2) The "old guys" did it about as good as it could be done
In other instances I wonder what the heck these guys were thinking. (ie a national driver of an mgb with multible national wins telling me to "beat a wooden dowel into the distributor hole to stop loss of oil pressure when you take the distributor out to change to crank fire ignition", and another famous MGB person telling me after I paid $400 for a billit cam and recieved a Datsun cam with a chunk missing out of the rear bearing surface, "I shipped you the cam with epoxy on the place I screw up on your cam, just re-glue the groove I accidently put in the cam, it must have fallen out durring shipping"! THIS FROM AN EXPERT?!
Basil, you are very good for me in getting me to ask questions and seeking answers.
As far as my flat tops, I am an army of one, every request I have made for help with $ or time in R&D has gone unanswered. I have built and tested both. I have not experienced power differences significant enough moving from a flat top motor to a pop-up motor to justify the differences in build time, cost or reliability. The valve to piston clearances, inconsistancies in chamber location and shape, and hot spots that are created on the pop up pistons are not worth it at my level of competition. In 3 years of racing, my weak link is not 12 hp. I just put in a quaife rocket and cut off nearly 4 sec on my lap time at summit Pt. from a stock MGB box. Do you think Pop ups would make that kind of difference? I know not. I have built 2 motors like mine for friends that are VERY happy.
Teq
Michael,
Nothing is going to take more time off the clock that driving experience. I'm pretty confident that a talented driver can still win with a weak engine. The engine I won the Northwest Division with was 12-13hp below what I usually had but I won with guile, skill, and staying off the brake pedal.
Will pop-ups make a significant difference - yeah. But you have to re-shape the chamberto accept the pop. If you're getting 14:1 with flat tops, I'm concerned about what's left of your head surface (did you do it by decking the block?)
I use the Quaife Rocket box (dog ring) too and love it. Is that why we didn't talk again about the extra square cut close ratio gearset I have :-)
I'm normally not in the practice of changing a threads direction, but since I think everything there was to say here about headers has probably been said, I will.
Dome shape for the MG heads has been a joke every time I've been involved with one. Everyone uses a Cosworth dome (or some variant) and if that is something done to keep with some sort of vintage legality, then fine, but if not, you're throwing HP away. There has to be something to be gained through improved chamber/dome compatability I am sure. This is something I DO plan to test on, but it's still some time away for me because I don't have a legion of customers beating my door down for it. On that note, there will be some things I test anyway (build it and they will come), but that's all I have to say about that right now.
I have no difficulty believing Michael's claims, he's a smart guy with an analytical mindset that sets him apart from many in this game.
Basil: Have you done significant testing with scatter pattern cams at all? I'd be interested in your opinion between standard and scatter profiles?
Sean
Hap, if you feel this is taking away from your thread, I'll happily start a new one.
Oh no Sean, the header part was played out. I too feel the same way you dod about dome pistons designs currnetly being run in MGB engine. Many years ago we built some domed piston 1098 SCCA G-prod engine, we started from stratch on piston domes. We ended up starting with a extra thick deck flat top piston, cut a angle on it on the lathe, in your mind picture the angle coming up and then an circle on top that was originally the flat top piston deck, we then make tooling to be able to laocate the center of the combustion chamber and cut the exact angle into the combustion chamber. This is what I'd like to do for a MGB engine. Alot of really good race engine builders relive thier combustion chambers by hand porting for domed pistons which I never thought to very acurate. It was a good twenty years later of looking at alot of top notch builders before I saw someone doing what we were doing with the heads, it was a Huffaker 948 race motor. All the work we did was manually, CNC were way too exoctic back then. I fiquire to do this for MGB motor, just to get to the point have 4 useable pistons in your hand would run $4-5K, and then the motor building would start on a motor that would easily run $10K, like you siad Sean, not many people knocking down the door for that kind of commitment.
The domes I use aren't Cosworth - they're asymmetric pop-ups that improve swirl, squish and flame propagation. The scatter stuff is still ongoing and there is power but not where the commercial scatters seem to think :-)
Oh well to change gears again, Kent didn't do too good in GP today at the runoffs, at times he was up in the top 4 thru 6, but must have had something happen, his times started to slow up about half way through the race, tough luck. ON a happier note, our buddy right up the road in Hendersonville, NC Jay Marlowe waxed the field in his Toyota Carolla and won the GP national championship, this was Jay's first ever runoffs. Rumor has it, GP will now be consolidated into FP and HP.
Nevermind, I read the story. Marlowe had a healthy lead of 7 seconds. FP runs tomorrow.
Jesse Prather wins his second FP championship in his Miata.
"""""""If you have a better mouse trap, or header design, sell it! """"""""
I can see it now............header for your XYZ car .....max effort design CFD, 6 axis trick of the week technology. $2800.48. You want it coated ?? Add $275. Inside also ?? $250. In stainless?? add $800.
Now if the person/company selling the above part has a car or team and runs XYX cars you STILL WONT be getting the exact part that they have spent 500 hours and a year developing. (Not that you can afford the three large for the above unit.)
Posted by: Sean Brown (63.135.223.---)
Date: October 12, 2007 03:11PM
"""""it just seems like everything off the shelf is junk. """"""""""
The majority of headers are sold to street car users.....the vast majority want "how much" and not "how good", cheap most oftentimes means junk.
"""""""""Merge collectors are no magic, Jere Stahl says 1-2HP max on a 700 HP V-8 is standard over a good conventional collector."""""""
Just was at a race-engine shop that I am very familiar with about a month ago who does Chev & Ford V8 only and had a Chev on the dyno. Going from an off the shelf Hedman drag race header (4>1) set and collectors and the only change was to Burns collectors with the same primary pipe lengths they picked up 50 horsepower from 6-7000 rpm wich translated into 8% difference. Even then...was that the optimum set up? Probably not. But at $700 a day they stopped there.
JerryB Wrote:
What you often times see on our race cars is a flat 3 into one collectors, this seems to be a popular design as it helps with ground clearence on race cars. here's a picture of a Spridgetech Midget 3 into 1 tunnel exhaust system, notice the collector, now this thru the transmission tunnel exhaust system so the collector is turned sideways to work on this system but imagine it as a under the car system and the collector being turned run flat for under car use.
The one I ordered from Kirk has a flat collector, but it runs under the car and not through the tunnel.
Speedracer Wrote:
Sean Brown Wrote:
Just to address the post about Ken't performance, he had a really sad thing happen. His new pistons give him over 15:1 compression. But each plug has to be perfectly indexed to keep from getting closed by a piston tap. #1 got turned a bit and the piston closed the plug gap giving him 3 cylinders. I w3onder if he's still using the extended tip plugs? :-)
Just to complete the circle given that Hap posted on my behalf. I received the new header from Kirk. Here are two quick pictures I snapped after taking it out of the box.
Eric from South OZ The exhaust you show is a Hans Pederson from Victoria. He trades as High performance products and there about as good as you can get. I have his complete system on my supercharged B and like it a lot. He makes it in several diameters up to 2.5" for racing but I went for the 2" as its a road car and I thought the noise might be easier to control.
Denis Wrote: