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GM 3.4L V6: Recipe for 200HP?

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GWHITE75 Avatar
GWHITE75 Gold Member Gary White
Sugar Land, TX, USA   USA
1973 MG MGB "OldBlue#2"
1975 Chevrolet Corvette Stingray "Old Red"
2006 Chevrolet Corvette "OldBlue"
In reply to # 3803146 by Jim Blackwood But is 200hp really enough?

Jim

HAAAAAAA! Jim has that TOP GUN fever. “I feel the need, the need for speed” And his car has it too.

After being on both sides of the HP fence my whole life, the extra power was always exciting, but ate up tires and broke parts a lot more. Adequate power can be fun too. One of the most fun cars I ever built was a 96 Miata and after installing a Flyin Miata turbo kit, boost at 8lbs pushing the HP to around 200, that car felt like a go cart with a radio, very fun to drive and could get out of its own way.

I think 200 hp can be a good baseline, then go up from there, if need be. It’s just a money thing.

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bills Avatar
bills Bill Spohn
W. Vancouver, , BC, Canada   CAN
The cars today with over 200 bhp weigh a heck of a lot more than an MGB - my Solstice has a wet weight of right at 3,000 lbs. and it has 260 bhp. In a 2,000 lb MG, you only need a couple of hundred bhp.

An AC Cobra 289 weighed about 2300 lbs. It had 271 bhp - which was the old gross rating and equates to about 220 net. If you stick a 200 net hp tuned 3.4 into a ~2,000-2,100 lb MG. you are going to have pretty much what a Cobra did.

Few have complained that a Cobra was a slow car, but Gary's Miata would be close to it (and would handle and brake much better).

I see no reason to say that 200 in a little British car is in any way inadequate. Jim's statement that today's cars are about the same size as ur MGs is both untrue (most modern cars are larger) but also misleading as modern cars tend to be MUCH heavier than the MG which had no side intrusion beams etc.

And if you are all thinking in old gross power, you better take the 200 new style power and start thinking about it as 240 bhp old style.



Bill Spohn www.rhodo.citymax.com/carstuff.html
Current: 1958 MGA Twincam (race car (170 bhp)),1962 MGA Deluxe Coupe (98 bhp)
1957 Jamaican MGA (200 bhp)1965 1971 Jensen Interceptor (350 bhp)
2009 Pontiac Solstice GXP Coupe (350 bhp)
2007 BMW Z4M coupe (340 bhp)
Recent: 1969 MGC roadster (175 bhp),Jensen CV8 (375 bhp),
1969 Lamborghini Islero S (350 bhp), 1988 Fiero GT turbo (300 bhp)
North Vancouver BC

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Gotcha!

OK now fess up, how many of you drive a car that is trimmed out under 2200lbs? I've been to the weigh-ins and they are few and far between, especially with the driver aboard, and without the driver? Just doesn't count, does it. With the RB cars coming in at 2400lbs, a 200lb driver, 100lbs of gas and another 100lbs of tools, spares and luggage it isn't unusual to be pushing that 3000lb number and while with 200 hp that ain't exactly a slug, it ain't no muscle car either. Take on a passenger and you'll notice the difference.

Just wanted to point that out.

Jim

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bills Avatar
bills Bill Spohn
W. Vancouver, , BC, Canada   CAN
In reply to # 3803337 by Jim Blackwood 100lbs of gas and another 100lbs of tools, spares and luggage

And of course the modern cars that start at 3,000 lbs. wouldn't also have the same load f crap added, driver included?

BTW, as gas weighs in at 6.2 lbs. per US gallon, so please advise where you mounted the 16 gallon gas tank in your car......

As for 100 lbs. of spares, did you really need to take that spare transmission.....



Bill Spohn www.rhodo.citymax.com/carstuff.html
Current: 1958 MGA Twincam (race car (170 bhp)),1962 MGA Deluxe Coupe (98 bhp)
1957 Jamaican MGA (200 bhp)1965 1971 Jensen Interceptor (350 bhp)
2009 Pontiac Solstice GXP Coupe (350 bhp)
2007 BMW Z4M coupe (340 bhp)
Recent: 1969 MGC roadster (175 bhp),Jensen CV8 (375 bhp),
1969 Lamborghini Islero S (350 bhp), 1988 Fiero GT turbo (300 bhp)
North Vancouver BC

BMC Avatar
BMC Gold Member Brian Mc Cullough
Minneapolis, Minnesota, USA   USA
Jim,

For the weigh in Wisconsin British V8 meet 2008, my 1980 MGB came in at 2,250. It was basically dressed for autocross: VERY Full tank of fuel with less than a block from the station to the scales, no spare, nothing floating around in the car, no driver. Yes, it has rubber bumpers and being a 1980 model year, it has beams in the doors amongst other items that add weight. If I remove the bumpers and then add and subtract for the wheels and lots of aluminium brake parts that I now have under the car, I am sure hoping that I can say the car today MIGHT come in Just under the 2,200 pound mark.

-BMC.


Member Services:
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BFC Avatar
BFC Ben Clark
Allegan, MI, USA   USA
1980 MG MGB "Kilr B"
1980 MG MGB MkIV
In reply to # 3803337 by Jim Blackwood Gotcha!

OK now fess up, how many of you drive a car that is trimmed out under 2200lbs? I've been to the weigh-ins and they are few and far between, especially with the driver aboard, and without the driver? Just doesn't count, does it. With the RB cars coming in at 2400lbs, a 200lb driver, 100lbs of gas and another 100lbs of tools, spares and luggage it isn't unusual to be pushing that 3000lb number and while with 200 hp that ain't exactly a slug, it ain't no muscle car either. Take on a passenger and you'll notice the difference.

Just wanted to point that out.

Jim

I'm working on it. Just took the rubber numbers off of their impossibly heavy mounts. I think they are a shared part with an M2 Bradley AFV. If Harbor Freight hadn't discontinued their roller kit for square tubing, I'd already have a set of aluminum ribbed bumper mounts done. Should be able to drop nearly 50 pounds off the car by the time I am done. I think that the ex-Mustang 5.0 engine is going to take all that weight back and a bit more though. I think I can get within spitting distance of 2200 - minus driver, spare tire, and driver's spare tire, but I'll probably give up an extra 100 pounds for creature comforts like Dynamat and a stereo system.

With a very mild build on the 5.0 engine, I'll probably get about 250-260 HP and maybe 290 ft/lbs of torque. Even at 2400 pounds curb weight, that should be a good amount of power. Still, I found myself wondering just yesterday if there was room for a supercharger...



I don't know. It's always smoked like that/made that sound/done that.

GMATS Avatar
GMATS GERALD MATLIN
palm beach gardens, FL, USA   USA
My 1978 B has the 3.4 RWD V6 that was rebuilt with a Crane cam, headers, carb & dizzy. Front & rear bumpers removed. Interior has Miata seats in place of the originals and15 inch wheels. I have no idea what the car weighs, what is the hp at the crank or the wheels but I do know it is quite peppy and is a blast to drive. I can break the wheels loose from a standstill and squeal them on the shift to second when the throttle is wide open. Would more hp make me happier? Maybe yes or maybe no.

However, the build was so easy with Bill Guzman’s kit that If I have a few hp less than a V8 it’s okay. Also, since the V6 & T5 is almost the same weight as the original 4 banger & 4 speed when you make some small changes to the suspension system such as poly bushings, 15 inch wheels with summer tires, rebuilt shocks & upgraded sway bar you end up with a really fun car with, in this writer’s opinion, more than enough power to put a big smile on your face when you drive it.

If you want or need more hp that’s okay. There is no right or wrong. It’s what you think is best for you. To get the hp of a V8 in your B you need to put in more time and effort which means you need greater skills. I wanted a fun car that could cruise all day, enter the freeways without me feeling I was going to get run over, have good handling & braking and I could accomplish that end with my skills. That end result was achieved. I don’t think I have the skills of Madman and even with his skills there have been a number of roadblocks he has had to face and overcome. If I hit those roadblocks I would not have been able to easily overcome them. But since Bill Guzman has done all the hard work as long as I followed the instructions I was able to build a really fun MGB that probably produces something close to 200 hp. I think if the goal is 200 hp that can be achieved with 3.4 RWD V6.
If you have an RB car you can take off close 100 lbs by removing the bumpers and in some states given the age of the car you do not need to replace them (FL). Drive without a spare, jack and tools, 1/2 a tank of gas and without the driver you might be around 2100 lbs. If your V6 is putting out 185 hp your power to weight ratio is 11.35 to 1. That’s not a rocket ship but it is a ratio that means the car should be quite peppy. I can attest my B is in fact quite peppy. With some more work on the engine and some other weight reducing of the body I think a 10 to 1 ratio can be achieved which should make for a fine little rocket ship.

Bottom line I’m very happy with my B and its performance. Hope this helps you make a decision.

1744 Avatar
1744 Gold Member Bill Guzman
CA, USA   USA
1973 MG MGB GT "Renegade I GT"
1974 MG MGB "Renegade"
Ok power to weight ratio. In the USA is measure per lbs in Europe per ton.
easy formula (just a ratio) hp X weight = P to W R. divided by 10-------hp per 10 pounds is the standard.
My RD weight is 2088 lbs / hp is 230 (supercharged) = ?

2017 Camaro SS P.W.R is 8.1

2017 Mercedes Benz AMG ($49,950 standard) PWR 9.2


Do the math for a 2250 MGB with 160 hp You will be surprise. Now compare to other vehicles.
Add correct gear ratio and things get better.



It is our attitude that will determine the outcome


Member Services:
MG Classic Conversions V6. Wilwood brake dealer.
Wray Avatar
Wray Gold Member Wray Lemke
., SC, USA   USA
Bill, now that is a real eye-opener, thanks. I think there might be hope that I can actually have an MG that can beat a mom-van to the next light.

BFC Avatar
BFC Ben Clark
Allegan, MI, USA   USA
1980 MG MGB "Kilr B"
1980 MG MGB MkIV
Wray-
I had the same reaction, so I made a chart.
https://www.mgexp.com/phorum/read.php?83,3758262



I don't know. It's always smoked like that/made that sound/done that.

ImVman Avatar
ImVman Vincent C
Advance, NC, USA   USA
1979 MG MGB
Another reason why I chose with the V6 is the refinement of Bill's kit; everything fits, everything is easy to service. The engine is sitting behind the front axle, the drivetrain is lighter than the original, the torque is impressive, the engines design, in my opinion, is a great design and very little if anything at all goes bad on these engines. these are things that you want for a tastefully modified sports car. They respond well with upgrades, and despite of what others think, there is still pretty good amount of aftermarket available for these engines, and can find another drivetrain for next to nothing anywhere. only things that cost a good amount of chedder for my engine anyway were the ROSS pistons I had made, and the camshaft that I had customized, other than that parts are still readily available.

Wray Avatar
Wray Gold Member Wray Lemke
., SC, USA   USA
Ben, thanks for that link, fun stuff. I don't want crazy HP but do want to be respectable when it comes to getting in front of a frickin Camry. New cars have so much advanced technology and are marvels of engineering. It's mind boggling how much they can wring out of a 4 cyl engine.

bills Avatar
bills Bill Spohn
W. Vancouver, , BC, Canada   CAN
In reply to # 3804400 by ImVman only things that cost a good amount of chedder for my engine anyway were the ROSS pistons I had made,

I have also used Ross - for forged pistons for my turbo V6 and for my 1950 CC MG DOHC motor. They give very good service and produce a high quality product that you should never have to replace unless something else comes unglued in the engine.

Wray, if you really want to beat the minivans, you need up to date tires - I am talking Michelin PSS quality, and a limited slip diff - Quaife works well on the street. But it means a big change in wheels and probably wheel wells, at least at the rear. 17" rims gives you the ability to run the narrowest sizes the modern high performance stuff comes in - need a 6.5-7" rim. No point attaining the appropriate power to weight ratio if all you can do with it is sit there and spin your tires. The BFG G Force Sport Comp-2 are also quite good (I use them on another car) and may come in sizes that allow you to go with 16" rims only 6" wide.

Sadly, old performance tire sizes are seldom available and the tires I use on my Jensen Interceptor are the same (including size) that I used on my Chrysler minivan....confused smiley



Bill Spohn www.rhodo.citymax.com/carstuff.html
Current: 1958 MGA Twincam (race car (170 bhp)),1962 MGA Deluxe Coupe (98 bhp)
1957 Jamaican MGA (200 bhp)1965 1971 Jensen Interceptor (350 bhp)
2009 Pontiac Solstice GXP Coupe (350 bhp)
2007 BMW Z4M coupe (340 bhp)
Recent: 1969 MGC roadster (175 bhp),Jensen CV8 (375 bhp),
1969 Lamborghini Islero S (350 bhp), 1988 Fiero GT turbo (300 bhp)
North Vancouver BC




Edited 2 time(s). Last edit at 2018-09-05 10:24 AM by bills.

Wray Avatar
Wray Gold Member Wray Lemke
., SC, USA   USA
Bill, I hear what you're saying and will burn that bridge, or tires as may be, when I get to it. Some of that issue also depends on your driving style; clutch-dumping launches off the line or a more reasonable take off then whacking the power to it.

I've bought the engine and trans and will fetch them next week. The project starts in earnest after that.

bills Avatar
bills Bill Spohn
W. Vancouver, , BC, Canada   CAN
In reply to # 3804495 by Wray Some of that issue also depends on your driving style; clutch-dumping launches off the line or a more reasonable take off then whacking the power to it.

I adopted the reasonable approach early on, both because I am not the type to be endlessly amused by smoke and black marks on the road, and because I was doing my own wrenching, and having to change a clutch on an MG is a PITA. As a result, I have never had to change a clutch on a car I have owned and built, due to wear, including the race cars (I have had to change a couple due to oil leakage onto the clutch facings, unrelated to driving style).

Used to hate it when a race organization I competed with was doing standing starts for a year or so - both because of the potential clutch wear and because of the distinct possibility that one car would attempt to embed itself into the exhaust pipe of the car in front when that car stalled or broke during the start.

I think automatics are probably a great choice for drag racing types.



Bill Spohn www.rhodo.citymax.com/carstuff.html
Current: 1958 MGA Twincam (race car (170 bhp)),1962 MGA Deluxe Coupe (98 bhp)
1957 Jamaican MGA (200 bhp)1965 1971 Jensen Interceptor (350 bhp)
2009 Pontiac Solstice GXP Coupe (350 bhp)
2007 BMW Z4M coupe (340 bhp)
Recent: 1969 MGC roadster (175 bhp),Jensen CV8 (375 bhp),
1969 Lamborghini Islero S (350 bhp), 1988 Fiero GT turbo (300 bhp)
North Vancouver BC

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