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Mr. Motorhead Mad Scientist
Joined: January 06, 2004 Posts: 717 Location: Practitioner of 36hp alchemy
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Posted: Sun Feb 02, 2014 12:25 pm Post subject: |
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Something I see missing here is what the general purpose of this engine/car will be. Is it to be a second or third car that is being built with the "fun ride" mind set that won't be driven more than about ten miles in a whack? Or will it be driven daily or semi daily with some 150-200 mile runs thrown in? Or perhaps a commuter type road warrior? As we all know, the weakest part of the whole 36hp platform is the valve train........it is what it is.
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I haven't had ant cam/lifter problems running at 6500 on one engine and 7500 on the other. I believe Blackline/Wakefeild engine turns 8K with no issues |
Adding stronger springs is one remedy (and proven to work), but I would wonder what the cam lobes and lifter faces would look like after 30k miles with the heavy springs. That is why I tend to be somewhat conservative in the respect of changing the valve train any significant amount. By all means do what you think is best for your application, I think it's very cool that so many people are even giving it some thought. I recently scored a set of NOS 25hp inner springs that I will be running in my stock 36hp for the salt (that car falls into the road warrior category) along with the new HD springs already on it. That engine now has about 3k long and short distance road miles on it. I'd just like to get two or three hundred more RPMs out of the engine at full throttle. _________________ 30 years experience in the sales of new and used auto parts!
36 horsepower parts for sale at http://www.aircooledresearch.com/
Or the new site at http://www.bugparts.com
Check out the Bonneville project:
http://aircooledresearch.com/docs/thebonnevilleproject.html#
"All limitations are self imposed."
Some Chinese guy |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Sun Feb 02, 2014 1:34 pm Post subject: |
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cool, thanks for that. It has helped. I guess this is a minefield that you can only find out about by walking into it...
So i have 2 options, I am using stock cam and 1.25:1 lifters
AEA525 which will be 73.5 lb seat, 125.5 lb @ 0.25" lift, and 138.5 lb @ 0.31" lift with ratio rockers
or... I can use the outer spring only which is rated at 35 lb seat, so I am guessing (will have to check in the morning) this will behave correspondingly with the above, giving 65.95 lb @ 0.31" lift. This is not enough right?
sheesh!
there are stronger dual springs too, so I could look at just using the outers on them... giving me more options.
my big question is what will the stock cam and ratio rockers allow me to use??? |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Sun Feb 02, 2014 4:37 pm Post subject: |
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to answer your question mr.motorhead, it is a fun weekend car that will be used for long runs too to 'bad camberg' and the like... so 300miles plus over a few days.
my main purpose is fun, more grunt and speed in modern traffic and some kind of longevity... and a run at the land-speed challenge here in the UK too.
thanks all for the advice so far... much appreciated. |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Tue Mar 11, 2014 4:57 am Post subject: |
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A small update.
Heads back from welding (there were a couple of broken fins) and adding some extra meat around the intake port before it is machined down a little.
Here are springs / valves / caps / collets etc.
Now off to machine shop for new seats and spring height set etc. |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Sat Jun 07, 2014 12:19 pm Post subject: |
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Picked up my heads from the machine shop today. Very excited to start building them up. Also got a very special little package from SPEEDWELL USA...
Valves dropped into place just to have a look...
New seats cut for the slightly wider valve springs and new BMW e30 guides.... and locators for inner springs fitted...
Inner spring in place...
...and outer spring. Hope this works!
Welded and cut back the inlet area... and notched the SPEEDWELL covers.
Manifold flange made... just waiting to bend up some pipe.
Back in the box for now... will put it all together next week! Can't wait but must!
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markhuebbe Samba Member
Joined: March 08, 2006 Posts: 379 Location: St. Louis, USA
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Tue Jun 10, 2014 3:06 pm Post subject: |
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Valves and guides are the stock 7mm size. Guides began as BMW e30, but have been machined to fit the inner spring locator, which is specific to the springs themselves. make sense? |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Thu Jun 19, 2014 7:25 pm Post subject: |
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Heads done! Bench tests showed 87cfm @ 0.4" lift... pictures etc tomorrow |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Fri Jun 20, 2014 2:34 am Post subject: |
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All done! Now for the rest of the engine.... |
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henry roberts Samba Member
Joined: February 24, 2003 Posts: 1276 Location: australia
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Posted: Fri Jun 20, 2014 4:03 am Post subject: |
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1/2 again is a nice addition.
any chance of some close ups of the ports and chambers for us do it yourselfers? edit, I just looked back at the first page. |
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henry roberts Samba Member
Joined: February 24, 2003 Posts: 1276 Location: australia
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Posted: Fri Jun 20, 2014 4:27 am Post subject: |
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Rome wrote: |
Your difference in weight of your intake valves is 8%, so draw a new line 8% higher than the one for the stock springs. This is Physics 101. That higher line would provide a guideline for the new springs, if using a stock cam.
8% is still at the tolerance of stock spring variations, so if you use the stock cam and stick with the maximum stock engine rpms, I think you'll be OK with the new valves.
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when calculating out the new spring pressure needed do we need to consider just the weight of the valve or the weight of the valve, pushrod/lifter (times by 1/the rocker ratio?) and some percentage of the rocker?
I'm not trying to be an ass, physics at school was a LONG time ago and I have forgotten most of it. |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Fri Jun 20, 2014 5:11 am Post subject: |
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I have no idea!
I just went for some BMC ones that were the right length and not too crazy stiff... although much stiffer than stock VW. As Mr Motorhead pointed out... my cam might not last too long but we shall see.
I just figured if they were OK in an old A series engine then I might be alright, or I could perhaps take out the inner springs.... or whatever.
I am winging it a little. |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Thu Jul 03, 2014 3:49 am Post subject: |
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So after musings on other threads I decided my best intake manifold would be a 1500cc single port, with some customisation of course.
Nothing new here I know, but my methods may make some of you laugh, so here goes!
As my motor is a long way form my home (the car is at shop being welded up) I had to try to adapt this manifold as best I could without it. Using a 30hp manifold I measured and measured again, plotting it all on some card.
Then I cut the 1500cc manifold just where it curves down into the ports, and turning these pieces was able to make them sit flat like the 30hp and not at an angle as the original did. With a bit of a twist on one side too I was able to do this and match the offset of the 30hp heads perfectly (ish)...
So to hold it altogether I had to make a jig of sorts to take to my friends for a couple of tack welds... and after many failures I saw my son's duplo lego lying all around me on the floor... so I used it!
the manifold was held off the surface at the perfect height, and orientation!
results as follows...
now all I have to do is weld it up nice, make it 40mm narrower and remove the warming pipe thingy.
I LOVE LEGO! |
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avus Samba Member
Joined: November 11, 2005 Posts: 268 Location: Drain, Oregon
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Posted: Thu Jul 03, 2014 7:28 am Post subject: |
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pig-pen wrote: |
So after musings on other threads I decided my best intake manifold would be a 1500cc single port, with some customisation of course.
Nothing new here I know, but my methods may make some of you laugh, so here goes!
As my motor is a long way form my home (the car is at shop being welded up) I had to try to adapt this manifold as best I could without it. Using a 30hp manifold I measured and measured again, plotting it all on some card.
Then I cut the 1500cc manifold just where it curves down into the ports, and turning these pieces was able to make them sit flat like the 30hp and not at an angle as the original did. With a bit of a twist on one side too I was able to do this and match the offset of the 30hp heads perfectly (ish)...
So to hold it altogether I had to make a jig of sorts to take to my friends for a couple of tack welds... and after many failures I saw my son's duplo lego lying all around me on the floor... so I used it!
the manifold was held off the surface at the perfect height, and orientation!
results as follows...
now all I have to do is weld it up nice, make it 40mm narrower and remove the warming pipe thingy.
I LOVE LEGO! |
Nice engineering. Looks to me like the recurve of the end pipes will clear the fan shroud well. I think you may still need to remove some of the aluminum heat exchanger for clearance under the generator stand. |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Thu Jul 03, 2014 4:18 pm Post subject: |
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thanks!
I am a great believer in using whatever you have to hand.
At present the manifold sits 20mm higher than the 30hp so yes i will need to do something... my heads are machined down so I have a few mil there, and I can remove 10 from ends of the manifold, so in total I am going to be perhaps 5mm taller than original.
Also there is no plug wire tube to worry about, although I may try to make one fit if I can.
And yes, I thought the extra kick out would help give clearance as you say.
Now I need to get it onto a block somewhere! |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Tue Feb 03, 2015 2:56 pm Post subject: |
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progress... I have been doing stuff, but mainly resto of body etc... focus now back on motor.
first up the dizzy, took a stock 36hp distributor had a resto done (found a good place in the UK if anyone is interested!) and put on a new can to advance on carb vacuum, and retard on boost from the manifold... came out very nice I think. Only giving 3.5º retard but I can adjust this when the car is set up on rolling road.
should help to stop the knock!
next up is my charger pulley. A bit of online-scrapyard (ebay) rooting delivered a pulley from a mazda rx8... the right size for boost I want and the right belt style too. Only it was too tall, so it was sliced and re-welded to sit as close as possible to the stock 36hp pulley. Also added some 'dogs' to locate in the 36hp holes.
question... should I weld through the bolt holes onto my original 36hp pulley? or use a big washer with my crankbolt?
or both??? the washer welded to the rx8 pulley?
opinions happily received.
cheers for now! |
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avus Samba Member
Joined: November 11, 2005 Posts: 268 Location: Drain, Oregon
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Posted: Wed Feb 04, 2015 3:51 pm Post subject: |
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pig-pen wrote: |
progress... I have been doing stuff, but mainly resto of body etc... focus now back on motor.
first up the dizzy, took a stock 36hp distributor had a resto done (found a good place in the UK if anyone is interested!) and put on a new can to advance on carb vacuum, and retard on boost from the manifold... came out very nice I think. Only giving 3.5º retard but I can adjust this when the car is set up on rolling road.
question... should I weld through the bolt holes onto my original 36hp pulley? or use a big washer with my crankbolt?
or both??? the washer welded to the rx8 pulley?
opinions happily received.
cheers for now! |
I think your pulley should center on something besides the bolt. Even if you weld the washer to your blower pulley, it should extend through and center in the stock pulley bore. If you don't weld the washer, it should have an additional step to center in the blower pulley bore, too.
I don't understand how your distributor vacuum can is going to retard under boost. What am I missing?
Nice build. I'm looking forward to seeing it through. |
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pig-pen Samba Member
Joined: December 04, 2012 Posts: 570 Location: United Kingdom
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Posted: Wed Feb 04, 2015 4:52 pm Post subject: |
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the vacuum can goes both ways... it has two inlets, one on each side.
not sure I follow on the pulleys... I will read again!
edit... ok, so it does centre on the middle of the stock pulley... and has the dogs through the holes too???
should I do more? |
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avus Samba Member
Joined: November 11, 2005 Posts: 268 Location: Drain, Oregon
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Posted: Wed Feb 04, 2015 6:01 pm Post subject: |
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pig-pen wrote: |
the vacuum can goes both ways... it has two inlets, one on each side.
not sure I follow on the pulleys... I will read again!
edit... ok, so it does centre on the middle of the stock pulley... and has the dogs through the holes too???
should I do more? |
so long as the blower pulley centers on the crank pulley, and not just on the bolt, I think you should be fine. My Judson pulley has a step that centers on the crank pulley, and 2 pins that engage the slots in the crank pulley--similar to your setup except the dogs you made fit the pulley slots much better.
The vac can is designed to retard with vacuum on the back side. If you apply boost pressure there it will not retard the timing. |
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Kjell Roar Samba Member
Joined: December 08, 2008 Posts: 1326 Location: Norway
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Posted: Thu Feb 05, 2015 1:30 pm Post subject: |
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pig-pen wrote: |
I have no idea!
I just went for some BMC ones that were the right length and not too crazy stiff... although much stiffer than stock VW. As Mr Motorhead pointed out... my cam might not last too long but we shall see.
I just figured if they were OK in an old A series engine then I might be alright, or I could perhaps take out the inner springs.... or whatever.
I am winging it a little. |
How to measure stiffness in springs, in Swedish
(use Google translate or better...)
http://boxerville.se/forum/viewtopic.php?id=1265&p=4 _________________ I got a historic car, every scratch got a history...
My car, Aug. 4th, 1955 / an early 56: http://www.thesamba.com/vw/forum/album_page.php?pic_id=610438 |
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