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Floating VW
Samba Member
Joined: April 28, 2015
Posts: 1596
Location: The South Zone
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 Posted: Thu Jan 20, 2022 7:30 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| spencerfvee wrote: |
| i never thought when i wanted to build a mpg motor that people would be interested in building a mpg motor . being every one wants duel port heads dual carbs and big stroker motors .lol that was a shock to me this has been fun to do we will have to see what happens when i get it into a vw bug . a lot of great info on this forum . thank every one spencerfvee |
Oh man, you should have seen the amount of horseshite I had to wade through 12 years ago when I started doing research into my own MPG motor. If I only had a dollar for every time I got laughed at by some jamoke behind the counter who told me I'd be better off just building a 2276 for less money. I'm glad the scene has changed over the past few years.
| spencerfvee wrote: |
| update i just read hot vws mpg motor build . they talked about light weight lifters light weight rods and using straight cut gears on the inside of the case . i was taken back by hot vws using a bosch 009. . . |
I thought the Hot VW's MPG motor got off to a great start, but then rapidly went off in the wrong direction. There were a few things they should have done, but didn't. And a few things they shouldn't have done, but did.
Definitely make the valve train as light as possible. Lightweight titanium-core lifters, stock aluminum pushrods, small valves, titanium retainers, and stock-weight valve springs, or even beehives if you can get them. A stock cam grind with straight-cut gears is the perfect way to round off this combo. Just one or two of those things won't make much of a difference, but all of them together makes for very lightweight package!
The 009 distributor is one of the mistakes Hot VW's made, in my opinion. There's no way to take advantage of a lean air/fuel ratio with only a mechanical advance distributor.
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vamram 
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Joined: March 08, 2012
Posts: 7300
Location: NOVA
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| Posted: Thu Jan 20, 2022 8:10 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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I frequent this forum to learn as I'm waay out of my league...but here you go.
https://www.thesamba.com/vw/forum/viewtopic.php?t=621196&highlight=
I couldn't get it to work as advertised.
| spencerfvee wrote: |
ok any one ever try one of these on there motors. gene berg sold them hot vws tryed it on there mpg motor build . i know in the 1970s when guys ran a open plenum manifolds they would put wire mesh in the intake manifold to help mpg and performance spencerfvee
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spencerfvee
Samba Member
Joined: August 19, 2004
Posts: 3071
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| Posted: Thu Jan 20, 2022 8:33 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| Floating VW wrote: |
| spencerfvee wrote: |
| i never thought when i wanted to build a mpg motor that people would be interested in building a mpg motor . being every one wants duel port heads dual carbs and big stroker motors .lol that was a shock to me this has been fun to do we will have to see what happens when i get it into a vw bug . a lot of great info on this forum . thank every one spencerfvee |
Oh man, you should have seen the amount of horseshite I had to wade through 12 years ago when I started doing research into my own MPG motor. If I only had a dollar for every time I got laughed at by some jamoke behind the counter who told me I'd be better off just building a 2276 for less money. I'm glad the scene has changed over the past few years.
| spencerfvee wrote: |
| update i just read hot vws mpg motor build . they talked about light weight lifters light weight rods and using straight cut gears on the inside of the case . i was taken back by hot vws using a bosch 009. . . |
I thought the Hot VW's MPG motor got off to a great start, but then rapidly went off in the wrong direction. There were a few things they should have done, but didn't. And a few things they shouldn't have done, but did.
Definitely make the valve train as light as possible. Lightweight titanium-core lifters, stock aluminum pushrods, small valves, titanium retainers, and stock-weight valve springs, or even beehives if you can get them. A stock cam grind with straight-cut gears is the perfect way to round off this combo. Just one or two of those things won't make much of a difference, but all of them together makes for very lightweight package!
The 009 distributor is one of the mistakes Hot VW's made, in my opinion. There's no way to take advantage of a lean air/fuel ratio with only a mechanical advance distributor. |
.................................................................................................................................i am happy the way every one has posted. very friendly great info. like i said i did not think people would be interested in a mpg build but they are . i to was shocked hot vws used the 009 dizy. they ran dual carbs maybe they could not get a vac dizy to work with the dual carb set up they were using ??? i thought they would have used a bosch 205 dizy . all vw bugs used a full vac. dizy till 1967 then the auto stick dizy came in 1968 for auto stick bugs only .can you tell me why a vac only dizy gets great mpg for the vw bug i would like to try a all vac dizy with my test 30pict 1 carb . your right about using alum. push rods . and straight cut gears . . i thought of using a stock cam . but went with a engle w 90 cam because it has 265deg.duration. and has less lift than other cheater cams. some of my best street motors ran super well using a cam with 265 duration . but i am rethinking on using a stock cam . my mpg build is not 100% all out mpg motor. because i am using 90.5 pistons .i all so thought about using 90.5 82mm storker pistons and cut the cylds.down and make a short motor .we did that on are drag race motor and it reved up rear fast and and lasted 8 years in a drag bug . i used 35mm intake 32 ex. valves .. the valves are bigger than a 1300 motor valves . i did use SS valves . .all so i do want to stay with a center mount carb . thank you for your info your making me think lol spencerfvee |
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oprn
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Joined: November 13, 2016
Posts: 12710
Location: Western Canada
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| Posted: Fri Jan 21, 2022 6:17 am Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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Remember to temper anything you read in Hot VWs magazine by the knowledge that thier job is to sell products for their advertiser base.
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oprn
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Joined: November 13, 2016
Posts: 12710
Location: Western Canada
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| Posted: Fri Jan 21, 2022 6:36 am Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| Floating VW wrote: |
| oprn wrote: |
| modok wrote: |
But if we talk about reducing the mass of the rods and pistons I don't think you would have any objection.
What about the RATIO of the rotating to the reciprocating masses. |
This right here I have often though about over the years. I have seen counterweights of various sizes and shapes offered for sale but they never specify what rod and piston weights they work best with! That to me has always been a glaring omission! Does that indicate that the research has never been done? I cannot believe that there is a one size fits all solution. I also believe that is part of the reason some bore/stroke combinations prove to work better than others.
| modok wrote: |
| A VW engine with a heavy crank and light pistons and rods is super smooth and quiet. Vibration and noise is caused by lost energy right? |
Indicating in my mind that this is an area that needs much more research. Unfortunately it's way above my pay grade to pursue... |
I did a little research into this concept, and this was the route I ended up taking with mine:
A full-weight flywheel, counter-weighted 76mm crank, and a 6.5 pound pulley for rotating mass. 560 gram H-beam rods with 83mm pistons shaved down to 373 grams for reciprocating mass.
It is, by far, the smoothest running engine I've ever had. |
Interesting!
The question in my mine is how much of this smoother running came from getting the reciprocating/rotating mass balance closer to correct and how much came from just adding total mass as a pulsation dampener?
I just built a basically stock 1600 with a counterweighted crank and lightened flywheel and it too is much smoother that stock. I credit that to two things. 1) getting a better reciprocating/rotating mass balance and 2) moving some mass from the flywheel to inside the engine reducing the diagonal forces that happen when the flywheel tries to absorb the power thrust of the pistons.
Common sense tells me that the ideal engine would have enough rotating mass directly in line with the reciprocating mass that a flywheel would not be needed. That would take a fairly bulky crankcase I think...
Anyway this is getting more into the engine design realm than the OP intended and beyond what we can do at ground level!
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spencerfvee
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Joined: August 19, 2004
Posts: 3071
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| Posted: Fri Jan 21, 2022 7:42 am Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| oprn wrote: |
| Remember to temper anything you read in Hot VWs magazine by the knowledge that thier job is to sell products for their advertiser base. |
....................................................................................................................i thought the same thing when i read hot vws and CB mpg story ...........hot vws has done that for years sell sell keep the advertiser happy . one must read what they have to say about how to build a mpg motor. and over look the sales pitch lol lol spencerfvee |
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Lingwendil
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Joined: February 25, 2009
Posts: 3988
Location: Antioch, California, a block from the hood
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| Posted: Fri Jan 21, 2022 8:24 am Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| spencerfvee wrote: |
| oprn wrote: |
| Remember to temper anything you read in Hot VWs magazine by the knowledge that thier job is to sell products for their advertiser base. |
....................................................................................................................i thought the same thing when i read hot vws and CB mpg story ...........hot vws has done that for years sell sell keep the advertiser happy . one must read what they have to say about how to build a mpg motor. and over look the sales pitch lol lol spencerfvee |
| Floating VW wrote: |
The 009 distributor is one of the mistakes Hot VW's made, in my opinion. There's no way to take advantage of a lean air/fuel ratio with only a mechanical advance distributor. |
Right? When I first read the article I was like 
Totally inappropriate if they really wanted to go for highest MPG, it would have made much more sense to go with nearly any SVDA, but my guess is that none of their sponsors likely offered a suitable one at the time, or they didn't think the average reader would be interested in the extra work to dial it in 
A programmable ignition setup would have been good too, but at the time of the article I think most were not offered by sponsors, prohibitively expensive from folks like MSD, or not readily available in the US.
Reminds me, I really need to set up a locked out distributor to try out my Daytona TCS-1 timing controller 
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Lingwendil
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Joined: February 25, 2009
Posts: 3988
Location: Antioch, California, a block from the hood
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| Posted: Fri Jan 21, 2022 8:45 am Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| oprn wrote: |
The question in my mine is how much of this smoother running came from getting the reciprocating/rotating mass balance closer to correct and how much came from just adding total mass as a pulsation dampener?
I just built a basically stock 1600 with a counterweighted OEM crank and lightened OEM flywheel and it too is much smoother that stock. I credit that to two things. 1) getting a better reciprocating/rotating mass balance and 2) moving some mass from the flywheel to inside the engine reducing the diagonal forces that happen when the flywheel tries to absorb the power thrust of the pistons. |
My recent 1776 is the smoothest engine I have personally ever driven- I used a DPR crank and flywheel that were both already balanced to eachother, and I used a postal scale to match the weights on each rod assemply as a group, and piston/ring/pin/clip assembly painstakingly to within .1 grams which is actually not as difficult as you think- just time consuming. I bet if I had the pressure plate done at the same time it would have been even better, but even just doing the other parts made a huge difference. I think going with lightweight rods would be even better next time, and probably even smoother. Surprisingly easy if you have a bunch of rods to choose from to get the weights all to within a couple grams to begin with, and then start sorting for whatever gives you the closest deck heights. But if you have the cash buying a set of H beams from CB may be more cost effective in exchange for your time.
A personal idea is to do a 74x90.5 with 5.325" lightweight H-beam rods, counterweighted crank, lightened flywheel (not crazy light) and 36 horse cam gearset for reduced thrust losses, but not as much whine as a straight cut set. stock pushrods trimmed to fit, lightweight lifters, mild cam, and 37x32 heads with ported intakes. I bet with 36DRLAs or 36IDFs 35MPG highway would be attainable relatively easily with the right gearing and ignition map.
Other idea that's been on my mind after reading this is an 1848cc- CB 69.5 crank engine with 92mm toyota pistons with the thinner ring set, the different drag loss may make up for the bigger bore and longer rod requirements enough to tune similarly. $219 for a 69.5mm crank from CB is a real bargain,and a little different too 
1848cc and 1904cc are both on my short list of next builds to plan for, so now I have some cool research leads
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Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884
Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0
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spencerfvee
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Joined: August 19, 2004
Posts: 3071
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| Posted: Fri Jan 21, 2022 12:48 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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back on page 2 i posted that i was going to use a stock vw crank.. .after reading all the post on this forum ..on what crank to use for best mpg motor . all were saying to use a counter weight crank for better mpg .. over using a stock . . i hat changing my mind but the more i though about it they all were right . i was going to build a drag race motor . and had this brand new bug pack 69mm counter weighted crank. with brand new light weight strocker rod a scat brand new lighten fly wheel all i have to do is take apart the gears on the crank and install the straight cut cam gear... all so this crank and rods and fly wheel are balanced to dead on O . to date i have a total of $2,935.00 in this mpg motor build. spencerfvee
Last edited by spencerfvee on Fri Jan 21, 2022 1:00 pm; edited 1 time in total |
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spencerfvee
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Posts: 3071
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| Posted: Fri Jan 21, 2022 12:55 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| should i use a windage tray on my mpg motor i used a windage tray on my vee motors but i drilled a lot mor holes in the windage tray . some guys say no some guys say it would help get better mpg let me know what you think i am trying to keep this moto simple lol lol spencerfvee |
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Lingwendil
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Joined: February 25, 2009
Posts: 3988
Location: Antioch, California, a block from the hood
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Max Welton
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Pruneman99
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Joined: February 22, 2012
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Location: Oceanside
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| Posted: Fri Jan 21, 2022 2:29 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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Is a windage tray really necessary? This is a MPG engine right? I don't think it's going to wind to 6k.
MPG engines are not going to have a huge cam with a bunch of overlap. I would use something pretty mild.. idle to 4.5-5
Unless we just left mpg and went formula vee. |
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Lingwendil
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Location: Antioch, California, a block from the hood
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Max Welton
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vwracerdave
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Joined: November 11, 2004
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Location: Deep in the 405
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| Posted: Fri Jan 21, 2022 2:48 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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On a MPG engine I really don't think how heavy the rods, pistons, and valve train are is a very important factor. Hopefully your only cruising at 3000-3200 RPM. You're not building a 7000 PRM screamer. Driving no faster that 65 is key because the aerodynamic drag going faster kills MPG. I feel gear ratio and tire size is a very important part of getting good MPG and if always neglected in these discussions. Something that can help a Bug MPG is the long forgotten Harrod Helper. They say that simple little wing can help get 2 more MPG by breaking up the negative pressure following behind the Bug.
I've always been told a windage tray doesn't do any good on a long highway drive. It only helps in hard cornering to keep oil from sloshing abound. Yes it was a useful item in FV racing, but not normal street driving.
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spencerfvee
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Joined: August 19, 2004
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| Posted: Fri Jan 21, 2022 2:56 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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hi update i just rejeted the pict 34 carb . theres things you must take care of be for you bolts the carb on your motor . . fist off i take out the fuel shut off valve. every one cuts the plunger off. i then block it off with a pict 28 or pict 30 1 main jet holder it makes for a clean look. next .i put a 132 main jet in the carb i then install a solex 1.5 needle and seat it is a bigger needle and seat than the needle and seat that comes with the pict 34 carb .i have found out over the years that a 115 air jet with a 130 or 132 main jet wakes up the pict 34 carb. next i adjust the acc. pump jet .so when you open the throttle plate on the carb it gives a good pump shot to the opening end of the throttle plate .most new carb. have the pump jet in the middle of the carb this may cause a off idle bog when you take off .all so you must adjust the idle screw so it hits choke arm . you all ways want the throttle plate all the way closed . next i make sure the acc. pump is getting a full pump shot to the acc pump jet. i had to use a washer on the spring to get the best pump shot to the acc pump jet one thing with new pict 34 carbs is the throttle plate is not open all the way to get it to open all the way i had to file the throttle arm to get it open all the way thats all folks lol spencerfvee
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spencerfvee
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Joined: August 19, 2004
Posts: 3071
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| Posted: Fri Jan 21, 2022 3:04 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| vwracerdave wrote: |
On a MPG engine I really don't think how heavy the rods, pistons, and valve train are is a very important factor. Hopefully your only cruising at 3000-3200 RPM. You're not building a 7000 PRM screamer. Driving no faster that 65 is key because the aerodynamic drag going faster kills MPG. I feel gear ratio and tire size is a very important part of getting good MPG and if always neglected in these discussions. Something that can help a Bug MPG is the long forgotten Harrod Helper. They say that simple little wing can help get 2 more MPG by breaking up the negative pressure following behind the Bug.
I've always been told a windage tray doesn't do any good on a long highway drive. It only helps in hard cornering to keep oil from sloshing abound. Yes it was a useful item in FV racing, but not normal street driving. |
.................................................................................................................hi dave good point and your right on about going 65mph some of are ohio road have ac 70mph speed limit x2 on the tire size. i am going to use the 4125 ring gear we have some big hills in ohio to climb oh yea the harrod helper it realy works thanks for your input spencerfvee |
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Pruneman99
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Joined: February 22, 2012
Posts: 5013
Location: Oceanside
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| Posted: Fri Jan 21, 2022 3:04 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| Max Welton wrote: |
| Pruneman99 wrote: |
| Is a windage tray really necessary? |
My 1776 w/Berg CW crank would uncover the oil pickup under very mild driving until I put a 1.5qrt sump on it. Freaked me out first time it did it.
Max |
Interesting. I don't think I've heard of anyone saying this was an issue. Don't get me wrong, I'm not discounting your experience. Was it a "standard" counterweighted crank? Or did it have counterweights that were added? |
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spencerfvee
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Joined: August 19, 2004
Posts: 3071
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| Posted: Fri Jan 21, 2022 3:05 pm Post subject: Re: stock mpg motor build counter-weighted crank or stock crank |
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| Max Welton wrote: |
| Pruneman99 wrote: |
| Is a windage tray really necessary? |
My 1776 w/Berg CW crank would uncover the oil pickup under very mild driving until I put a 1.5qrt sump on it. Freaked me out first time it did it.
Max |
..........................................................................................................something for me to think about spencerfvee |
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