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gimmesomeshelter Samba Member
Joined: May 08, 2004 Posts: 1468 Location: San Carlos, CA
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Posted: Sun Dec 11, 2011 5:36 pm Post subject: How much should I budget for head porting |
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Hello-
I have a set of raw ( no valves, springs, guides ) repro Okrasa heads that I needed ported. How much should I budget for a high quality porting job (not counting the cost valves, springs, etc.)?
Cheers,
Paul _________________ "I would rather have questions that can't be answered than answers that can't be questioned."
Richard Feynman
Last edited by gimmesomeshelter on Tue Dec 13, 2011 2:56 pm; edited 1 time in total |
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RockCrusher Samba Member
Joined: August 03, 2010 Posts: 4596 Location: Parkesburg, PA
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Posted: Sun Dec 11, 2011 6:19 pm Post subject: |
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Hey Paul,
Depends what you want out of them. 1st you have to ask if you want to mod and original set of castings....yes? Since the engine they would go on is a pretty conservative project (I'm guessing) they should not need much modification. Depends who does them but the actual port work should be $200-250ish plus the guides and all the other doodads and the valve job. Figure $400-500 to put everything into a finished mode and ready to run. Probably closer to 500.
RC _________________ [email protected] Please use email for all general inquiries.
I will be happy to speak to anyone who has a serious inquiry (meaning real potential business for RC enterprises) or a parts order. Due to machining noise causing missed calls all calls will be returned promptly. |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Dec 12, 2011 10:02 pm Post subject: |
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That's a loaded question...
You know, it really depends on what application....
The ports on those things already look somewhat LARGE for a small cc engine, so if you plan to build a BIG cc or high rever, you should look at larger valves, larger intakes at least, and some port and chamber work to match them. Also a way to lift the valves high enough, is rather important
Or if building a SMALL engine, with limited valve lift, you might want to use the intended valve size but make the ports smaller or leave them alone, which is another matter
Whatcha plannin boss? |
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gimmesomeshelter Samba Member
Joined: May 08, 2004 Posts: 1468 Location: San Carlos, CA
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Posted: Mon Dec 12, 2011 10:29 pm Post subject: |
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Hello-
My goal is a 356 1600 Super wanna-be using a mish mash of 36hp VW, Porsche 356, repro Okrasa. Here's what I have so far:
NOS 36hp case
Scat superlite 356/912 crank
Carillo 356 rods
Billet aluminum oil cooler
LN aluminum cylinders (82.5mm)
Full weight 180mm flywheel
Dual Zenith 32NDIX carbs
Cam - probably something like a Pre-a super, or a "Maestro Grind" on a Pre-a blank.
WW repro Okrasa heads (the current valve diameters are 33mm intake, 28 exhaust).
1:1 ratio rockers
Full flow Fram canister filter
I want something that is enjoyable to drive (zenith carbs, full weight flywheel, modest cam), and given the money I've sunk into this thing already, I want it to last.
Regards,
Paul _________________ "I would rather have questions that can't be answered than answers that can't be questioned."
Richard Feynman
Last edited by gimmesomeshelter on Tue Dec 13, 2011 10:31 am; edited 3 times in total |
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splitpile Samba's Worst Speller
Joined: May 03, 2000 Posts: 5927 Location: back to living where hell meets the suface
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Posted: Mon Dec 12, 2011 10:57 pm Post subject: |
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OLLIES did my WW OKRASSA heads for 1000. That was full port and polish, match port intake manifold with aluminum spacers, make valve guides, valve job and deck to raise the compression, reshape chambers with-out welding. Expensive, cheap I don't know except we made 12 more HP which we contribute at least 8 of it to the heads
Don't know what the next welded up set will cost. Redoing the chambers, valve size, guide size, valve spring pockets, decking and more.
Call Roger at HEADS UP Performance, he has done some WW Okrassa heads also _________________ Stocking distributor of "The Funky Green Panels"
www.BUSTORATION.com metal and more for your bus
"no more hacking my sig line" |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Mon Dec 12, 2011 11:23 pm Post subject: |
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I see
I am no expert on the 36 horse cams, but from what I understand they limit the possible lift. To decide what lift is needed for the valve.......... or conversely, what size valve is needed to match the size of the port considering the lift you can achieve, is the first thing to figure
Something like pipemax could give you a reality check on the valve size, port size, runner size, carb vent size, runner length, and valve lift needed to make the most of it. The results may be surprising.
Once you figure out what directions you need to go in, then you can get some idea of how to go there.
If you could find all the info for me to plug in to the sim, I could give it a go, but as it is I have no idea about the intake diameters and cam specs on these things |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Sat Dec 17, 2011 9:32 pm Post subject: |
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I see a lot that could be done to the heads chambers.depending on piston type.but modoc is right,the key is to have it all work togeather for the intended app and the way you drive & where. biger isant nessarly better but proper disigine&funksion is.I would love to have the time & $$$ to do one of those old 36's up real nice.I think it would be a nice challange, both single port&o'crazzy style heads.hmm were those irish? good luck and who ever you choose ,choose wizely.and choose a real shop, not bubbajoes in sailem because he spins a wicked yarn of how good he is.Ive seen that tomany times and it,s usualy junk, or will be shortly.you need real time real cust feed back & real ### as in dyno,flow.something to compair it with.might not want to limit it to vw shops. |
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kmichael Samba Member
Joined: August 11, 2007 Posts: 89 Location: Marin
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Posted: Sun Dec 18, 2011 10:21 am Post subject: |
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Paul,
You might want to give Dave Bonbright at Engine Masters in Sonoma a call-since I see you're not too far from him. The modifications he's making on our 36HP Challenge engine are really novel, he's certain to have ideas on your build. Dave's phone number is 707-938-8122.
Regards, Kim _________________ "The star of the beetle is still shining with undiminished brightness and you see for yourselves every day what vitality there is hidden in this car..."HeinzNordhoff |
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Vintage oval Samba Member
Joined: September 13, 2004 Posts: 25 Location: Colorado
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Posted: Tue Dec 20, 2011 8:26 pm Post subject: |
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You might want to check the openings between all the fins. I purchased a set of raw heads from Wolfsburwest and had to clean out all the metal flashing that interfered with the cooling passages. It took a lot of time but it is worth it if you are going to get some serious hp and need the cooling. |
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Howard Sanson Samba Member
Joined: October 25, 2007 Posts: 68 Location: 15 and 91 frwy
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Posted: Wed Dec 21, 2011 12:47 am Post subject: |
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Your heads you have no seat think about larger vales { what is stock}go to the next size up in stainless steel. |
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splitpile Samba's Worst Speller
Joined: May 03, 2000 Posts: 5927 Location: back to living where hell meets the suface
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Posted: Wed Dec 21, 2011 4:07 pm Post subject: |
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Howard Sanson wrote: |
Your heads you have no seat think about larger vales { what is stock}go to the next size up in stainless steel. |
Bigger valves for a 36hp head are not easy to find. I had mine custom made.
35.5 intake and 33 exhaust. Should of made them a little longer for the springs I was going to use, ended up with jaguar duel springs and titainium retainers instead of my ford v6 modular engine springs i was going to use (to much spring pressure. _________________ Stocking distributor of "The Funky Green Panels"
www.BUSTORATION.com metal and more for your bus
"no more hacking my sig line" |
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gimmesomeshelter Samba Member
Joined: May 08, 2004 Posts: 1468 Location: San Carlos, CA
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Posted: Wed Dec 21, 2011 4:12 pm Post subject: |
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Hello-
Quote: |
I had mine custom made. |
I assumed that I will have to have my valves custom made. I'm also planning on using beehive spring an titanium retainers. That's why I asked how much porting will cost excluding the cost of the valves, etc.
Cheers,
Paul _________________ "I would rather have questions that can't be answered than answers that can't be questioned."
Richard Feynman |
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splitpile Samba's Worst Speller
Joined: May 03, 2000 Posts: 5927 Location: back to living where hell meets the suface
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Posted: Wed Dec 21, 2011 6:06 pm Post subject: |
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gimmesomeshelter wrote: |
Hello-
Quote: |
I had mine custom made. |
I assumed that I will have to have my valves custom made. I'm also planning on using beehive spring an titanium retainers. That's why I asked how much porting will cost excluding the cost of the valves, etc.
Cheers,
Paul |
I'm using behives, but the stock length valves were to short and created to much spring pressure. We are going to cut the spring pockets and then figure out how much longer the valve stem needs to be and/or move the retainer grove up as the behive retainers are half the diameter of stock retainers. Lots of geometry and shit to figure out, but getting close.
The WW Okrassa heads have had the chamber welded up to reshape it and the seat pockets will be cut and installed next. Ray Stephens is letting me use his Super Flow 110 flow bench to help get things flowing right.
I should have the 1.4 ratio rockers here after the new year to figure out how much lift works best so a cam can be ground accordingly. These heads will be totaly different design then my other 2 sets I've had done, just going to the next leval. _________________ Stocking distributor of "The Funky Green Panels"
www.BUSTORATION.com metal and more for your bus
"no more hacking my sig line" |
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earthquake Samba Member
Joined: January 10, 2008 Posts: 3984 Location: SANDY VALLEY, NEVADA
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Posted: Wed Dec 21, 2011 7:05 pm Post subject: |
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Check out Honda GL1100 Goldwing Valves and springs, the stems are just a bit smaller so that may take a little work, they have dual springs and I know for a fact that you can rev a GL motor to 8000 rpm no problem...
Goldwing on the left-----------------------------------------------------------------stock VW 36hp on right
The intake valve is 38mm and the exhaust is 32mm
check out this post...
http://www.thesamba.com/vw/forum/viewtopic.php?t=437391&highlight=goldwing+valve
Casey _________________ 74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison] |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Wed Dec 21, 2011 8:07 pm Post subject: |
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I would just find a biger stainless valve that would work,longer isant any big deal and there are someny to choose from, and go from there. |
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henry roberts Samba Member
Joined: February 24, 2003 Posts: 1274 Location: australia
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Posted: Thu Dec 22, 2011 5:13 pm Post subject: |
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has anyone thought about or tried inclining the valves on the ww heads?
to me it seems as though this would allow you to run a more modern chamber design and fit ratio rockers without moving the rocker shafts. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Thu Dec 22, 2011 5:45 pm Post subject: |
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sshh !! modern is a bad word in the world of vw's. eveloution has left us behind,and some like it that way.(not me I mod everything) |
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modok Samba Member
Joined: October 30, 2009 Posts: 26740 Location: Colorado Springs
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Posted: Fri Dec 23, 2011 12:23 am Post subject: |
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Tell me the dimensions of the valves you need, and the springs you need, and chances are I will know of where to get them
This is a side effect of my wasted life |
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gimmesomeshelter Samba Member
Joined: May 08, 2004 Posts: 1468 Location: San Carlos, CA
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Posted: Sun Jan 01, 2012 2:40 pm Post subject: |
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Hello-
Pardon me if this is OT.
I've been reading about the optimization of combustion chambers, it it looks like the Okrasa head could benifit from some. It already has a relatively small volume (45cc), but has a very open shape. It could be closed by welding in the areas marked below, but that would end up raising the compression.
I could lower the compression to an acceptable level by 1) adjusting the deck height, or 2) installing dished pistons.
If I had a choice between a flat piston top and an open combustion chamber, or a dished piston top with a closed combustion chamber, which should I choose?
Cheers,
Paul _________________ "I would rather have questions that can't be answered than answers that can't be questioned."
Richard Feynman |
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grueni Samba Member
Joined: November 03, 2008 Posts: 582 Location: Germany
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Posted: Sun Jan 01, 2012 5:32 pm Post subject: |
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if welding on the combustion chamber you need to put out the seats and get some new. and then go B form.
look at some denzels. that was for it's time the best. modern heads like jpm do the same. _________________ 1960 1584cc turbocharged, 35,5/32 (11,117s 1/4mile ) |
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