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MG MGB Technical - One Fast B!!!
| Got to drive David from Jacksonville's B Saturday evening. I built the engine about a year ago but Dave took a good while to get the Weber carbs right. Talk about fast, Also it idels smooth at 650rpm! I took it on my approx 1/4 mile up hill test spot. A typical rubber bumper B will do about 58mph. My rather worn GT 73Gt does about 60 to 62. (I weigh 304lbs.) My wife's Gt which is the quickest B I have tried there does 65 to 67. David's 67 With crossflow, Twin 45dcoe and a Peirce cam does 72.5 by his bickle speedo. Because of lag I say it does 74mph. A darn fast Car!!!!! The quickest car I have tested there was a 94Neon 5 speed. which did 75mph. David has one quick B. Can't imagine what it would do with a 170lb person. Don't tell me the crossflow doesn't work. Bob thompson/International Auto. If you want performance with reliablty and good normal driving go CROSSFLOW!!! |
| Bob Thompson |
| Bob, Great to hear some more real-life stories on the crossflow! Give me a couple more days and I'll be able to tell how it feels too, Chris has nearly finished the new engine for my B (anyone interested in the specs?) Could you give us a bit more info on David's engine (or David, you could do this yourself of course, if you want to)? Regards, Alexander (counting down!!!) |
| Alexander M |
| I smell the cross-flow wars revisiting! What with the superchargers, hardly a word on cross-flows for a long time. Now this, another blatant testimonial! Well, I've gone the extra extra and sent the cross flow and manifold to Peter Burgess for magic, and will report when received and reinstalled. Please, lets hear some specs on the above engines. What I really gotta have now is an Eaton adapted to the cross flow with Han's 2.5 jet-hot coated header! Vem |
| vem myers |
| As I see it the super charger is a simple but expensive way to simplely bolt on horsepower to a solid engine. But from what I have heard not even in the same league as a Crossflow. A crossflow with proper mods could be beyound believe! A real sleeper. Bob |
| Bob Thompson |
| Vic, Kelvin mentioned a while back that a possible route is to take a Weber 32/36 crossflow manifold along with a Miata supercharger kit and perform some cut-and-paste. David |
| David |
| Bob, I am interested in you having a favourite stretch of road to test your cars over. Using the terminal speed saves the need for someone to operate the stop watch! Close to where I live is the route that the Healey family used to use testing. It was described in a magazine a couple of years ago. The problem is that parts of it are a bit heavily used these days. David |
| David Witham |
| Vic, Here are the specs for my new engine: - HRG Derrington crossflow head, modified by Peter Burgess to 'Fast Road Big Valve' spec - 18V block, bored to 1950cc, using JE forged pistons (a liner in one piston) - Aldon dizzy, mechanical advance only (not vacuum) + Aldon electronic ignition - 2x Dellorto sidedraft carbs 40DHLA (=Weber 40 DCOE) - lightened flywheel by 3lbs (if I am not mistaken) - pretty much everything balanced - Piper 285 cam (sorry Cameron, yours seemed a bit too wild for what I'm looking for) - I believe a Spridget heater valve - tuftrided rocker shaft I think that these are the major components (I might have forgotten some of course). David and Vic, What engines are you guys running? Regards, Alexander |
| Alexander |
| Alexander, Here is my basic set-up. 1966 18GB engine Engine bored .060 over Stock flywheel. Lightening might have been nice, but it revs quite quickly as-is. MSX head cut to result in 10.56:1 CR Alloy valve spring keepers HD valve springs MSX cam ground for 4 port intake Cam properly indexed by Bob Thompson(engine builder)using Moss 3 position timing set and off-set keys Twin 45DCOE carbs jetted and flowbenched by Mike Pierce of Pierce Manifolds K&N filters/velocity stacks Allison electronic ignition (15-20 year old NOS) Stock 1966 exhaust manifold Falcon big-bore stainless exhaust 1973 water pump, pulleys and fan Homemade evacupan crankcase ventilation Geo Metro alternator, homemade mount Seltec A/C compressor, homemade mount Stock radiator NGK BPR7ES plugs (one step colder than stock) Bosch premium wires (trust me, dont use cheap wires) Future mods? Send head to Sean Brown or Peter Burgess for flow work. |
| David |
| David, Thank you! I'm kinda interested in the evacupan thingie! Could you explain a bit more? You also made me realise I'd forgotten some things: - +- 10.8:1 CR - full DoubleS Big Bore exhaust (2") - K&N filters (I believe part number 56-1340, are these the ones you're running too? after asking around it seemd these are as big as you can go) - stock (thoroughly cleaned) radiator - dynamo (I'm not really planning on changing this one until it fails) - MGOC silicon wires (ugly blue...) Any idea on output btw? Alexander |
| Alexander |
| Will you guys cut it out-I'm turning green over here and my wallet is starting to ache. Seriously, hearing about these ultimate B series engines is delightful. Detailed specs and maybe 0-60 times are welcome. I would love for one of you x-flow guys to set up a web page focused on this with photos, details and driving experiences from all of you. I suspect your mid range torque is awesome-the stuff dreams are made of.... |
| Terry |
| Alexander, I'm not sure what K&N part numbers I'm using, but they are rectangular and if they were any bigger, they wouldn't fit. HP? I don't know, but I wiegh 270 pounds and I have heavy Fiero seats, AC, alloy knock-offs which weigh a ton and overdrive and I still run 0-60 in just over 9 seconds without slipping the clutch or abusing the car. I just have a to be careful not to rip my little D-type overdrive out while showing off! The best part of driving my car is the torque at mid and high speeds. 80-85 mph in overdrive is bliss. Here is an old post I left on the BBS ref. the evacupan... First off, I take no credit for this idea. It's an old concept that I heard about from a friend who was a national-level drag racer and later I read more on the subject in a book on tuning A-series engines. I also remember seeing a kit advertised by Jeg's or Summit. A 5/8" or so metal tube with a 45-60 degree mitred end is welded (or JB Welded) in the exhaust pipe just downstream of the collector. The tube needs to be inserted about 3/4 to 1 inch into the exhaust pipe at about a 135 degree angle, pointing towards the rear of the car in a fashion such that the exhaust gas passes over the mitred end creating a venturi effect. An anti-backfire valve is attached to the outer end of the tube and a hose connects that to, in my case, the front tappet cover/oil seperator pipe that normally feeds the stock pcv assembly. A good vented oil filler cap or a quality aftermarket crankcase intake filter completes the setup. I really like this affair because I always have negative crankcase pressure and that helps keep seal leaks to a minimum and moisture out of my crankcase. With the engine running, a very noticeable suction can be felt at the end of the hose. It is also very clean looking with only a hose diappearing out of sight behind the bellhousing. I found a stainless air injection pipe ('80's GM I think) in a junk yard that was threaded for, and had attached, the proper anti-backfire valve. Since I have a stainless exhaust, a little TIG welding fixed me right up. I did install a new valve and I used silicone hose in the area of the exhaust. I've seen carbon steel versions of the air injection pipes as well. The person who told me about this has had his JB Welded in his exhaust for six or seven years with no problem. And no, this does not suck oil out of the crankcase. Hope that I made some sense. David |
| David |
| Alexander sorry but you are not going to get the best from your crossflow using a piper 285, I have tried it cheers Cameron |
| camerongilmour@aol.com/www.britishclassiccarspares.com |
| For those interested, go to Chris' site http://www.octarine-services.fsnet.co.uk and select Alex's 1950cc crossflow engine... (Thanks Chris!) Alexander |
| Alexander M |
| What kind of power are you getting from a 1950cc cross flow? Cheers |
| joseph phillips |
| Cameron Gilmour quotes 185 BHP on his engines using his scatter cam.... ~PHIL |
| Phil |
| Phil, Is that engine capable of being used as a daily runner? Cheers Joe |
| joseph phillips |
| As far as i know it is. I think some people dispute this, but as usual many of them (not all of course) have no real world experience. Just think of the slaggin off supercharging used to get before Moss brought out a kit, LOL!! Cameron's car is the bright yellow roadster that was on ebay recently, and has been in MG World. I have spoken to him via email, and that is him posting above. He has also put his name to the engine which he will build for you. Both Cameron and MG World seem to be of the opinion that it is a perfectly useful car as a daily driver, however i cannot verify this... If i wasn't so keen to build a supercharged engine, i would try a cross-flow without even looking in the direction of a *normal* stage 2 engine upgrade. Certainly the ford Crossflow units, as driven in most caterham 7 derivatives is a very capable, quick and reliable motor.... They are pricey mind - the head alone is £1k..... ~PHIL |
| Phil |
| WOW!! Just looked at the website!! 185BHP is very nice, but 4700quid is obscene. I know they must be made in very low quantity but I am suprised that someone would spend that much money on an engine. 800 pounds for a two Weber 45's and inlet manifolds is a bit pricey too! No way am I going to tune my MGB any more. Its just not worth it. Westfield Megabusa for me next! |
| joseph phillips |
| My brother is looking for two weber 45s and an inlet manifold for his vauxhall motor, price so far is just over 700 (without air filters) so it sounds about right.... Its not about the money though mate, its about, well.... if i knew, i'd tell you, but sometimes you just gotta do it!! ;-> ~PHIL |
| Phil |
| just bought a pair of 45's, without manifolds for 250quid. so thats 550 for manifolds!! yikes |
| joseph phillips |
| I am just a bit bored of my car at the moment! When I use it on track days it is 99% of the time the slowest car. It's fine in the bends, but I am fed up with being passed by standard cavalier SRi's! I think its the wrong car for me and will never be as fast as I want it! Will be selling it soon so I get something fast that isn't going to cost me over 5 grand for 185BHP. Cheers Joe |
| joseph phillips |
| Gosh, where did you find them..? £260 each new...! ~PHIL |
| Phil |
| Guys, this might interest you. 45 DCOE Weber Carburetor $275.00 plus shipping no tax outside California http://www.shadetreemotors.com/shadepartmgbmga.html I have no affiliation. David |
| David |
| Oh yeah, they sell the heads for $985.00. Cheapest I found. David |
| David |
| There has to be a catch here. Moss Motors sell those carbs for $429.00 EACH and the MSX heads for $1599.00!! That's just too good to be true. |
| Bill Findlay |
| Bill, I called to confirm the current prices since I have not spoken to them in a while. I got an answering machine, but that is not unusual. Just remember that an outfit with Moss's overhead has to make a substantial profit. David |
| David |
| Webers (and Dellortos for that matter) can be found at rather low prices on ebay and classifieds sites of car clubs. I bought the pair of Dellortos for a very good price, they were used items off an Alfa but in excellent shape (no play). I bought a rebuild set from the same guy, but when we installed that one, I didn't have the impression it had been necessary, although it's better to be safe of course. The head was not cheap (crossflow heads never are of course), but quite acceptably priced and it was exactly what I wanted. I guess the carbs compensated for what the head cost more and I still feel it was a good buy (thank you Roger!) (btw, do I notice some more people planning on crossflow engines? must be contagious... hehe) Alexander |
| Alexander M |
| Phil, No that was second hand and it was for the pair. Don't see the point in shelling out for new ones. Cheers Joe |
| joseph phillips |
| Sorry, have to correct an error: the pistons are not JE but Accralite (got that wrong, sorry...) Alexander |
| Alexander |
| The new Brit Tek price list/winter sale flier lists one "Barely Used" x-flow head with valves, manifold, two 45DCOEs and linkage for $1,800. Somebody may already have snapped it up but it is probably worth a call. (I'm tempted but have a head with SU manifold sitting in the dining room waiting for my attention; can't justify a second.) |
| Marvin Deupree |
This thread was discussed between 21/10/2003 and 28/10/2003
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