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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7216 Location: Videbaek Denmark
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Posted: Wed Apr 07, 2021 1:12 pm Post subject: Re: 2276/86b beetle daily |
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Iīd say let Alan test them, so you know where you are really at, then decide from his recommendation and your wishes on what to do. It is so easy for everybody else (us) to tell you what to do when we are not the ones that are laying down the funds for it. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Wed Apr 07, 2021 1:56 pm Post subject: Re: 2276/86b beetle daily |
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UK Luke 72 wrote: |
again. I'll have to Google how to get the centreline length, not sure if I'm tooled to be able to do that.
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To measure the center-line the best way is to use thin pinstripe tape. Stick it to the long side of the port wall. Trim it at the valve seat line, and then trim the other end flush with the flange. Do the same thing with the short side wall of the port. Carefully pull them both off, stick them to the table nice and straight, and measure them for length. The average of the two is the center-line length. You can also do the same thing with a piece of solder and make a mark on it.
With the centerline length, CFM, and the port volume you can use one of the Wallace calculators to figure the average port velocity. Personally I think the average velocity, port volume, and the Minimum CSA are the most important factors when building a set of heads. They are all tied in together, and knowing the average port velocity is a good indicator when comparing heads.
Brian _________________ www.type-emotorsports.com |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Fri Apr 09, 2021 9:07 am Post subject: Re: 2276/86b beetle daily |
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Had an interesting morning, he's not tooled up for measuring port velocity anymore, retiring and leaving the game.
Said there isn't any appreciable gains to be had and was pretty complimentary of the port work. Despite that, Torben was frighteningly accurate.
When I asked if he would do the ex. He said there's no point, it'll flow plenty enough.
Heres the flow figures at 10"
35cfm 3mm
67cfm 6mm
90cfm 9mm
99cfm 11mm
107cfm 14mm
With the TB on, 97cfm
With the air filter 89cfm
So going forward, quite happy that it only cost me Ģ30 as he had no suggestions for how to improve it but the ITBs he says will only support 150bhp and be all done by 6000 rpm
To minimise outlay going forward, and so I can use the car this summer. What are my options?
A different cam with similar lift but less duration? Alan didn't like the idea of adjusting the chambers too much. And I don't want to add a mountain of deck height. _________________ 2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172 |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Fri Apr 09, 2021 9:57 am Post subject: Re: 2276/86b beetle daily |
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Pretty close to what I was thinking as well. A pretty well set up 42mm valve with a smaller volume street port should be around 190-195cfm.
Did he test the exhausts at all?
Where is your seat lap line placed on the intake valve? Are the intakes back cut?
It looks like you have a pretty deep bottom cut on the seats already. Is there another angle between the bottom cut and the 45deg sealing cut?
Not much more you can easily do with the chambers.
From here, it looks like the throats could use some work transitioning from the short turn into the bowl, but its hard to tell without getting to stick my fingers in it for a feel.
Post some pics of the backside of the intake valves, measure the port volume and length, and maybe we can figure out a few more small gains.
Brian _________________ www.type-emotorsports.com |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7216 Location: Videbaek Denmark
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Posted: Fri Apr 09, 2021 11:31 am Post subject: Re: 2276/86b beetle daily |
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Well, as we discussed some time ago, the TBīs are too small, even for those heads, no matter what other people say. End of story.
Wrt the heads. Well, there is really not much you can do without sinking some time and money into them. The port volume is adequate for what the valve and seat flows, as there is no apparent "edges" in the curve.
I just let the Analyzer chew on a generic engine with your flow numbers, 70 cc port volume, 15" intake runner length and 36 mm ITBīs It barely hits 155 with cleaners and 162 w.o. air cleaners. (SAE 77. 300 rpm/sec. Similar to EØS) In spite of the healthy static CR the torque is also low, only about 200 Nm (149 ft lbs)
Today we tested a set of Revmaster heads that got sent to me to try and fix. They were CNCīd with the dreaded DRD L5/L6 program, an absolutely awfull job, and the guy paid big money for it. Naturally the engine never ran right. Poor fella. I have tried to correct them best I could. I am still not quite where I want to be, but close. Remember this is an unwelded Revmaster casting. There is only so much room to work with, and the short radius is too sharp in the exhaust port so it actually creates a vacum (!) I machined the seat out to 89,3% for a 43,7 mm valve to be a tad conservative and made a nice port which resulted in 189 cfm @ 0,600" and 28" but it kept increasing to 199 @ 0,800" So the port actually supports the seat. I want to see if I can find another 5 cfm by detailing the port even further. Thatīs most likely what is within my skills.
As for what you can do. Iīd say keep the cam and let it pull what it wants for the summer, but get some decent ITBīs and air cleaners. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Fri Apr 09, 2021 12:57 pm Post subject: Re: 2276/86b beetle daily |
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Not that this is the ideal setup for everything, but I have been having really good luck doing valve jobs like this. These were on some CB mini wedge ports I was correcting. Lots of angles, and nice big bottom cuts. The top cut also blends into the chamber nicely, but you have to watch and not hog out the radius up the wall of the chamber. I can pick up good numbers over a standard 3 angle. The placement of the seat on the valve face also makes a big difference.
Brian _________________ www.type-emotorsports.com |
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74 Thing Samba Member
Joined: September 02, 2004 Posts: 7391
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Posted: Fri Apr 09, 2021 1:28 pm Post subject: Re: 2276/86b beetle daily |
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Brian_e wrote: |
Not that this is the ideal setup for everything, but I have been having really good luck doing valve jobs like this. These were on some CB mini wedge ports I was correcting. Lots of angles, and nice big bottom cuts. The top cut also blends into the chamber nicely, but you have to watch and not hog out the radius up the wall of the chamber. I can pick up good numbers over a standard 3 angle. The placement of the seat on the valve face also makes a big difference.
Brian |
Are those Sleds old heads and what did they end up flowing? Did you change the 42mm intakes to 44s on them as well?
Thanks |
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74 Thing Samba Member
Joined: September 02, 2004 Posts: 7391
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Posted: Fri Apr 09, 2021 1:47 pm Post subject: Re: 2276/86b beetle daily |
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From the info posted and flow rates etc with your cam and compression would need better heads and larger throttle bodies be the best way to get what you want out of your engine?
If that is in the budget and you want to do it right it may be something to consider since you already went with better rings etc and everything must work together (and you have already had trouble with your current heads and I know that headache and disappointment).
If you stick with your current heads and throttle bodies and do not want to spend much more then maybe a cam swop would be more.
Torben and Brian E would be the ones to provide advise in this area, but it is something to think about! |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Fri Apr 09, 2021 2:57 pm Post subject: Re: 2276/86b beetle daily |
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74 Thing wrote: |
Are those Sleds old heads and what did they end up flowing? Did you change the 42mm intakes to 44s on them as well?
Thanks |
Yes, Sled's heads. 42mm valve from CB and way wrong ratios. They were 172cfm @ .500" and 182 @ .600" with the 42mm valve. All I did was add bigger 44mm valves, and do a correct valve job for them, and they went up to 195cfm @ .500" and 207cfm @ .600". The port volume was still huge, but they will be WAY better now.
Brian _________________ www.type-emotorsports.com |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Fri Apr 09, 2021 3:10 pm Post subject: Re: 2276/86b beetle daily |
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Really appreciate your input as always guys.
Thank you for sticking with it!
Intake valves are back cut
Exhausts didn't get tested. He liked how they were ported and repeatedly said they'll outflow the intake so not to bother. Despite offering another 30 quid he saw no point
Intake centre line is 68.5mm
I'll measure port volume tomorrow.
Bottom cut is around 3.5-4mm but not concentric, seat cut is between 1.5-2mm. Again, not concentric.
3 angles in there.
I'll grab better pics tomorrow, gonna get them vapor blasted.
I'll speak to Paul, see if he can supply just the throttle bodies without the linkage parts, fuel rail etc. 40mm? 42mm?
If not, I could bore them out to a reasonable degree of accuracy I believe if I can find suitable throttle plates.
_________________ 2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172 |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Thu Apr 15, 2021 2:56 pm Post subject: Re: 2276/86b beetle daily |
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68cc intake port
68.5mm centreline
180cfm @28"
280fps according to the Wallace calc.
Double checked chambers at 50cc
Bit of a delay because I had the chambers coated but didn't like the way the damage from the munched inlet guide looked, so I've flatted that back some more and they'll be coated this week. Gained maybe 0.5cc at most, as accurate as I can do it but after multiple attempts I've not added any appreciable volume to No2. _________________ 2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172 |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Thu Apr 15, 2021 4:12 pm Post subject: Re: 2276/86b beetle daily |
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What lift were the average FPS numbers calculated?
The 280fps is great. I shoot for 275-285fps average at the max lift I plan to run. Every head I have built in this range makes great torque.
The 68cc port volume seems small for a highish revving 2276cc with a 42mm valve. I am guessing some careful, and well placed material removal will gain you another 8-10cfm, and a little more RPM up top.
Just for reference, A set of 42x37.5 Tims S2's I had were 72cc. My best 40x35 heads were 66cc's.
What did the engine rev to before? I am eager to see how they work now.
Brian _________________ www.type-emotorsports.com |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Thu Apr 15, 2021 5:58 pm Post subject: Re: 2276/86b beetle daily |
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180cfm @ 28" is taken from my 107cfm @ 10" depression and 14mm or 0.551" lift. My fk10 is 13.59mm or 0.535"
Since I took that measurement I grabbed the other head from my car (12hr night shift at work) and that has the same 50cc chambers but one port is 70cc the other 3 check out at 68cc
Power is dropping off big after I'd say 6200-6500 but in 1st and 2nd it zings round to the 7500rpm.limit I used to have on it. I've since dropped it to 6500 or 6800. I can't remember.
Silly question, for the port volume, am I supposed to subtract the volume of the valve stem? I didn't, I just put some grease around the stem and the seat and filled it up. Dried it out with compressed air and repeated 3-4 times. _________________ 2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172 |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Fri Apr 16, 2021 9:14 am Post subject: Re: 2276/86b beetle daily |
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I always leave the valve in place since it will be in there while its running.
I looked back and saw your throat/valve ratio was 86.5%. I used this to get a 1.6sq" cross sectional area of your throat. With that...math says your 2276cc choke point is 6290rpm, which is right where you said the power dropped off.
At this point, I think you have pretty much maxed out the heads, unless you want to get into some more drastic and expensive reworking. You could pop those seats out, and install something with a larger ID, then blend the bowls, and try to find a few CC's in other areas.
You could also do a few things to the valve seat cuts and pick up a few more CFM, but that wont change the MCSA at all.
I guess you need to sit down and have a honest chat with yourself, and decide if you want more RPM, or if they will work as is... More RPM just adds more problems in my mind. I prefer the low down torque, and 280 average FPS is right in the range I have found makes for a killer driver. Your cam is a pretty close match for the engine size and RPM range.
Brian _________________ www.type-emotorsports.com |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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Posted: Fri Apr 16, 2021 10:56 am Post subject: Re: 2276/86b beetle daily |
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Hi Brian.
Torben has given a very similar thought via pm, essentially, a 44mm intake valve with the bowls blended would make the most of them, but as you say, where do you stop. If I decide more upper end is required it'll be time for some new heads.
I don't want to keep chasing upper rpm hp though, torque is where the fun is with a street car. And durability/reliability. I just want to enjoy it for the summer.
Does make me wonder how they made 160bhp on a 2276 with an fk10 when the ports looked like this and now I can only expect to hit 170 odd now, and that's with bigger itbs.
Vs
_________________ 2276 Beetle build https://www.thesamba.com/vw/forum/viewtopic.php?t=670744&highlight=2276+beetle+daily
2276 EFI Conversion https://www.thesamba.com/vw/forum/viewtopic.php?t=689172 |
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3291 Location: Rapid City, SD
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Posted: Fri Apr 16, 2021 12:32 pm Post subject: Re: 2276/86b beetle daily |
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Who's ports are those in the last 2 pics, and who said they were 160hp?
Brian _________________ www.type-emotorsports.com |
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UK Luke 72 Samba Member
Joined: September 07, 2011 Posts: 2867 Location: Little Britain
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sled Samba Member
Joined: February 16, 2005 Posts: 6179
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Posted: Fri Apr 16, 2021 1:10 pm Post subject: Re: 2276/86b beetle daily |
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those dyno numbers sound kinda fishy _________________ drive your split. |
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