Nice Port Work - UK Company Porting

Have an interesting technique, tool or just anything related to porting? Post it here . . . please no bashing anyone for the model of engine they are working, we're here to share ideas . . .

Postby 106-1194218389 » Fri Nov 30, 2007 1:52 pm

Boy do I agree with Larry! Years ago I was trying to break into the head porting business and was criticized by the nay-sayers because my ports were not "pretty". I generally leave my ports with a carbide finish and do not smooth them with cartridge rolls to be pretty so I was really hammered on to the point it affected my business. What was really funny is the cars running my heads were kicking butt. A car I did heads on and intake system won at Road Atlanta in SCCA F production 3 out of ten years and always finished in the top 3. Were my ports "pretty" #### no they just won.

John
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Postby SWR » Fri Nov 30, 2007 2:26 pm

larrycavan wrote:
SWR wrote:After reading up a bit on those heads and their PFA-sheets,I'm not impressed either... a 3.9375" bore adapter used on an engine with a stock bore of 3.5756"... Supposed to be a big-valve monster head,and the intakes are stock at 35mm (1.37") and the exhausts are 31mm (1.22") which is one mm up...port areas are off,and the "stock head" they're comparing with have smaller than stock valves... really,really impressive. ???

Wow!...you guys sure hammered on that site pretty hard hey...Now it's a free site and opinions are good things to get but just hammering away on those guys doesn't set well with me for a couple of reasons.

Judging by their website, I'd say they're not trying to hide anything. Their data is there to be evaluated and scrutinized. They provide plenty of photos as well. Two questions do come to mind though.

1. Are their numbers inflated as some seem to suggest but not provide any of "their" flow data to support their claims?

Well...maybe it's time to step up to the plate with some facts to support the flamatory opinions..Whadda ya say?

How about some Q & A time so there can be something substantial behind the hammering.

1. Who's run any of those heads on a racing engine?

2. Who's run against any of the heads those guys build with ones you've built? And equally important...does your stuff beat their stuff on the track? Only Curtis seems to have any input there.

I want to know if their heads work rather than everyone just hanging out their "cfm johnsons" and waggling them around.

I don't care if they use a larger bore adapter for a couple of reasons.

1. If the bore sizes are relatively close. It won't mean squat...maybe a couple of cfm.

2. As long as you compare apples to apples - use the same bore adapter for stock vs ported...who cares?


I also notice those that hammerd the hardest log IPs in the general neighborhood of product marketability as the CNC site. That being the case, I suspect there should be some first hand knowledge / experience with the company. If not through direct purchase then perhaps through race track competition.....

Let's hear what you got to say guys...I'm really interested in whey this ancient post got drug back up again and most especially why the European gang is so eager to tear down the port work...


:D
Larry C

[rant) My personal opinion:I myself cannot bring flow data to compare with yet,but when I'm done with the Ford Cosworth YB head I'm doing I can... It's substantially more "maxed out" than theirs,yet I doubt I'll see over 320cfm.. Just not enough area in them to flow that much,even with the relocated/welded ports we're using,and they're not...

Ok,so they have data on their page. I scrutinized it,and found several flaws,like data that's not comparable to much,as there's not much written in that data you would find on your,or any, YB head/engine. Would you sell a head that you know suffer from the bore shrouding the valves after flowing it on a much bigger bore,and with fancy numbers? I would not..I'd rather tell the customer the bore blocks some flow,and give him the numbers he can more-or-less replicate on any bench..i.e. if that was my PFA-file,I would not even post it if it stated I was using a 100+mm bore adapter on a block that's just under 91mm bore..

Bore sizes here are 3/8" off.. if that's ok,then I can just make bore adapters some 1/2" or 5/8" apart in dia and use them for everything? I don't think so..

This is not intended as bashing,neither the foreamentioned or what I'm about to say,but it's not the first set of heads I've seen advertized with "very good numbers"...except you can't see them yourself on your own bench,as you'd normally use a smaller,more appopriate adapter,and you can't make it flow anywhere close to that as soon as it's on the block.

Sorry,I'm just tired of all the "fantastic cfm and power heads" advertized just about everywhere that just don't cut it when they are tested,not on the bench and most of the time not on the track either...Just different ways of doing business I guess. [/rant] :)
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Postby larrycavan » Sat Dec 01, 2007 8:23 am

SWR wrote:

[rant) My personal opinion:I myself cannot bring flow data to compare with yet,but when I'm done with the Ford Cosworth YB head I'm doing I can... It's substantially more "maxed out" than theirs,yet I doubt I'll see over 320cfm.. Just not enough area in them to flow that much,even with the relocated/welded ports we're using,and they're not...


Fair enough


Ok,so they have data on their page. I scrutinized it,and found several flaws,like data that's not comparable to much,as there's not much written in that data you would find on your,or any, YB head/engine. Would you sell a head that you know suffer from the bore shrouding the valves after flowing it on a much bigger bore,and with fancy numbers? I would not..I'd rather tell the customer the bore blocks some flow,and give him the numbers he can more-or-less replicate on any bench..i.e. if that was my PFA-file,I would not even post it if it stated I was using a 100+mm bore adapter on a block that's just under 91mm bore..


I agree with that 100%.


Bore sizes here are 3/8" off.. if that's ok,then I can just make bore adapters some 1/2" or 5/8" apart in dia and use them for everything? I don't think so..


No...that's not what I said or inferred. I said that as long as the bores are CLOSE [not 3/8" but more in the order of say 1/8"] you won't see much flow difference. AND if you flow any particular head BEFORE and AFTER the port work, on the same bore adapter, then you get comparable results. The odd thing here is if their stock numbers are accurate and flowed on the larger bore adapter..then something is not right.

This is not intended as bashing,neither the foreamentioned or what I'm about to say,but it's not the first set of heads I've seen advertized with "very good numbers"...except you can't see them yourself on your own bench,as you'd normally use a smaller,more appopriate adapter,and you can't make it flow anywhere close to that as soon as it's on the block.


Well...I don't know exactly what to call it and I generally like things you post. I think you're a pretty sharp guy. I guess my point is simple. "If you're going to start a gun fight - bring bullets.":;):


Sorry,I'm just tired of all the "fantastic cfm and power heads" advertized just about everywhere that just don't cut it when they are tested,not on the bench and most of the time not on the track either...Just different ways of doing business I guess. [/rant] :)


Not familiar with those heads. I have to agree with you. IMO those are some pretty big numbers for a 34.8 mm valve pair. I'm not saying they're not getting them but if they are, they have tricks up their sleeve that I'd like to learn myself. :D

Flow numbers aside - because we all know flow numbers are the "elastic band" that may or may not prove out and may or may not produce HP - What's your personal experience / customer feedback - etc. on engines running heads ported by that company?




Edited By larrycavan on 1196512237
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Postby jsa » Sat Dec 01, 2007 8:51 am

[quote="larrycavan"][/quote]
Larry,

Nothing against the company, I simply stated to beware of bore adapter size as it might not be obvious what that means for a YB engine.

Consensus on the YB is that valve shrouding is an issue, and a larger bore adapter inflates the flow readings.

The flow readings they claim for a standard YB head are 15% above the readings I have gotten for a standard YB head.

You make many valid points in their defence, however I still maintain my concern about their results.

My biggest concern is that someone unaware of the effect of bore size for a particular engine's results might look upon those results more favourably than due.

It is also worth noting in _general_ that CNC gives excellent repeatability, but that in itself does not mean the product is automatically best of its kind. It could just be repeating less than stellar port shapes. I'm not saying the product in question is stellar or less so, just use of a non representative bore adapter raises questions.
Cheers

John
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Postby SWR » Sat Dec 01, 2007 10:27 am

larrycavan wrote:No...that's not what I said or inferred. I said that as long as the bores are CLOSE [not 3/8" but more in the order of say 1/8"] you won't see much flow difference. AND if you flow any particular head BEFORE and AFTER the port work, on the same bore adapter, then you get comparable results.
Agreed,I would not care if they used a 92.5mm bore adapter,as many YB blocks are bored to this size (generally they are between 91 (stock is 90.82) and 93mm).
The odd thing here is if their stock numbers are accurate and flowed on the larger bore adapter..then something is not right.
Their "stock numbers" are with a much bigger bore adapter and much smaller valves than the YB head has as stock...which is a few of the things that's sounding the alarm..atleast for me. :)

Well...I don't know exactly what to call it and I generally like things you post. I think you're a pretty sharp guy. I guess my point is simple. "If you're going to start a gun fight - bring bullets.":;):
Like I said..I'm making a stockpile of "YB"-ammo right now.. :laugh: ..I'll come back with guns blazing.

Not familiar with those heads. I have to agree with you. IMO those are some pretty big numbers for a 34.8 mm valve pair. I'm not saying they're not getting them but if they are, they have tricks up their sleeve that I'd like to learn myself.

Flow numbers aside - because we all know flow numbers are the "elastic band" that may or may not prove out and may or may not produce HP - What's your personal experience / customer feedback - etc. on engines running heads ported by that company?


I would not mind knowing those tricks (if they can do it) either...if I do so I reckon I'll see 335-340 on mine :cool: . But I doubt it. I'll be happy to see a real 300@ 28" out of them.
I have not had a personal dyno or race experience with them,but a friend of mine,which happens to be one of the most acknowledged YB-builders of all time stated that he was given this head by one of his customers for use on his block,which Jens assembled. I saw this particular head myself in Jens' shop. And Jens was close to 120 hp down compared to his own head...730hp from that head,850 from his (on the same block,with same parts..even same FI-map). Too bad I didn't ask to flow it. :(

And,I'm not thinking that these guys are the only ones..I've tested other companies "End all"-heads,and I have yet to see one that gives the numbers they claim. "CFM numbers make sales" you know...seems that's pretty much everywhere..


I know. That's unfortunately the case. It's not the end though. Over time, good information passes down to the customers. You educate a couple of yours and provide them with good end results from your porting....the chain begins and the link will grow.

I just want to say this because it's the crux of what I'm all about. Honesty and fairness DO PAY OFF over time. Maybe not in terms of $$$$$ all the time but in other, more significant ways. Sure the money is great to get but like you already stated and I agree 100%. If you have to mislead people along the way, it's not worth the ride. Personal integrity simply cannot be surpassed with money....[at leas not in my "little world"].

Best Regards,

Larry C




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Postby 106-1194218389 » Sun Dec 02, 2007 2:32 pm

What is a sad thing is that CFM is not the only story. A sewer pipe flows a lot of air. You have to pay attention to velocity and turbulence, how the air enters the cylinder etc. I have been listening to a CD I bought "Porting By the Numbers" an interview with Darin Morgan. In the interview he states that the NHRA Pro_Stock heads are actually smaller now then they were just a few years ago. He also points out that the exhaust valves on these 500 cubic inch engines are now only 1.800" where the stock off the shelf BBC heads are 1.880" He also dyno'ed an engine with 2 sets of heads. The ones that flowed more air lost 150 hp at 9500 rpm. They had a little turbulence .150" above his maximum valve lift but it killed the heads. So CFM is not everything. The time slip at the end of the drag strip is the best criteria.
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Postby jsa » Sun Dec 02, 2007 7:21 pm

jfholm wrote:

What is a sad thing is that CFM is not the only story.


Yeah, good reason to build our own bench, bypasses all the my cfm's bigger than yours rubbish.
Cheers

John
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Postby msj442 » Sun Mar 22, 2009 10:37 am

i just now got around to reading this thread and holy crap. its funny how i thought we were all for the same thing. i guess i know now that even if you post a comment, advice,etc. it will always get shot down no matter what it is. ive learned to just read and not post lately.

jmo, max

cool link larry.
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Postby jfholm » Sun Mar 22, 2009 12:13 pm

The one thing I like is we may not always agree but that is a good thing. We learn from these discussions. That is what is good about this forum there really is no contention or arguing, just good discussions. I think that is why the flow bench itself has turned out so good. We don't always agree on something but we are adult enough to discuss it and the cream always seems to float to the top.

John
It is a wise man that learns from his mistakes, but it is a wiser man that learns from the mistakes of others.
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