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Clevo120Y

crossflow porting results

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I thought I would start a separate thread for the head port I'm working on for the race head I'm going to be doing for a proddy speedway car.

This port is a C1A casting, and the results are using a stock standard crossflow intake valve, 1.8in single cut valve. The port has a 3 angle seat cut that is a little worn but still usable. So the first test was on the port as cast from the factory with the 3 angle seat cut, the second test is with the port ported and the third is with the port work plus the chamber work.

 

this is the stock valve I'm using

 

SAM_2786_zps45b15136.jpg

 

Stock combustion chamber and reworked chamber, not much needed here, just laying the edge over and blending to form a nice smooth shape, you have to take the point off the end of he swirl generator to stop pinging.

 

SAM_2790_zpsae438264.jpg

SAM_2791_zps209f0b00.jpg

 

This is the port work, hard to explain what I have done but most of the work is at the short turn and bowl area, I mapped the air velocity of the stock port to determine what material and shape needed to be used, the port responded well to being biased to the right.

 

SAM_2783_zps834af01b.jpg

SAM_2788_zps7c54fbc2.jpg

 

Here are the results

                     test1        test2        test3

50                 29.4         30.95       36.08

100               54            58.34       63.15

150               77.4         85.6         92.5

200               98.5         108.98     121.92

250               121.2       131.56     149.84

300               141.4       151.05     165.2

350               162.9       168.79     178.97

400               177.7       180.13     190.17

450               184.4       189.02     198.22

500               186.2       197.22     202.96

550               189.1       203          207.93

600                               214.2       213.98

650                               213.44     213.4

700                               212.16     212.2

 

 

So as you can see the results are reasonably good, the chamber work plays a big part of the power potential, this head now has a flow potential of 330hp using the stock standard intake valve.

Hope you find this interesting.

 

 

 

 

 

 

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Great work mate. Does the port work include opening the throats, I assume it does otherwise the low lift improvements are surprising.

 

I had convinced myself that when using a cam with 0.45" lift port work other than in the bowl area would be pointless as the heads would not be port limited at that point (they would be valve limited).

 

An even more progressive test which showed the influence of valve guide shaping alone would be interesting.

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Thanks mate, yeah an 89% throat to valve ratio I used, the chamber work and valve seats are the big improvers over a stock port with a single seat cut, the port work is just the icing on the cake that keeps the flow stable over the normal choke of 450 thou of lift.

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Do you think guide shaping has much of an influence under 0.5"-0.55" lift? Do you recon you'd get 200cfm without it? This is interesting for high k engines with modest lift cams and turbo builds.

 

Good work again. You have shown real evidence that you are searching for what makes the biggest difference and not just opening every up and saying "it must work, the car does 12s". Restricted classes of racing are best for separating who knows and who doesn't. Keep showing your efforts and I think it will pay off.

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With a 3 angle seat and with just some reshaping around the short turn and the right hand side wall just before the short turn and leaving the valve guide basically alone and no chamber work I made 202cfm at 550. If you did the chamber work as I did it above you will gain throughout the low and mid lift as well on top which is what we want even more so with a shorter cam.

 

SAM_2733_zps46a086cf.jpg

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Another thing, this port isn't hogged out, the first part of the port before the short turn is the same cross sectional area as stock, the burr has just been run around it to clean the carbon off and give it some texture

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First off awesome work bro.Your work is of the highest standard even on a test part,I like it.2nd I like the textured finish you add,seems some porters like it and some prefer a smooth finish? When Marty White did mine and Mossy's he did em both with a rough textured finish.Numbers don't lie...and now you have the proof to base your work off so it works for your application,so you could theoretically come up with a cam that would match your flow figures perfectly to help out your speedway customer's.

 

I know I would be worlds apart on cam choice v's head flow on xflows but it would be interesting to try one of these flowed heads back to back with the matched camshaft then another cam to see if a bigger lift longer duration camshaft would make any more HP and torque and for what reason if it improves or is worse.On a two barrel engine I think it would go backwards but a 4 barrel I don't know?

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With a 3 angle seat and with just some reshaping around the short turn and the right hand side wall just before the short turn and leaving the valve guide basically alone and no chamber work I made 202cfm at 550. If you did the chamber work as I did it above you will gain throughout the low and mid lift as well on top which is what we want even more so with a shorter cam.

 

SAM_2733_zps46a086cf.jpg

That's what I thought, but could not prove. Basically the extra port work is only required if you have over 0.55" lift. Agree on the chamber work, it has made an even bigger difference than I thought it would and is important for any engine.

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Thanks guys, the port works very well and I'm happy with it for this engine.

Sly, thanks mate I appreciate your comments, Yes from these flow figures a perfect cam can be calculated once I had the exhaust figures as well, as I have mentioned before this first engine is a compromise because of time and also the bloke has parts already that we have to use, a cam is 1 of those parts, he has a new cam already which has 542thou of lift after lash and just over 300 degrees of advertised duration with an intake centreline of 105 degrees from memory, I will have to check that. Pretty big cam and now that the head will keep up we can use all of that lift efficiently. I would like to do comparisons one day for sure, with this head port I believe you can use a cam of higher lift because this port stays stable even over the 600 thou lift mark it just doesn't flow any more air, his will most likely be a cross sectional area issue, the port is still reasonably quiet even at 700 thou. Ports that become turbulent over a certain lift point start to go backwards in flow by a fair amount and you can hear the air separate and go very noisy, this port doesn't do that.

The texture on the port walls is to keep the fuel atomised and stop it from clinging and pooling on the walls like a smooth port, also it is the same theory as a golf ball, the grooves and dimples in the wall cause a pressure drop when air is moving past them and creates a sort of layer beyond my knowledge to explain but it works to keep the air running along the port shape and not separating but not actually ON the wall itself if that makes sense, anyway textured finish FTW I have been chatting to some very experienced porters both here and in the US including Larry Mauex and dyno tests have also proven a horsepower and torque increase, they don't look like artwork and it's hard to convince people but I'm into finding what works not what looks good so my port work might not be the prettiest but the results are there.

Matt, the port work is required on the short turn and right hand wall for the port to be stable to 550 thou lift otherwise it falls over at 450 thou, you just don't have to work the valve guide or the bowl area very much at all, just open the throat to 1.615in diameter and do some blending to make the transition from bowl to seat nice and streamlined, it doesn't take much. Do the chamber work even if you leave the port standard and a 3 angle seat cut, there is so much low and mid lift flow to be had with just those 2 things.

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What kind of tools do you use to do the head and manifiold work? that is if we are privy to these secrets. 

Thank you for sharing all of your processes, i have found them to be extremely interesting

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Awesome work on this head.  Check out the low to mid lift improvements.  This head takes off like a rocket. Hello roller cam!!!  Interesting to see the gains slow down in the high speed areas but they are still increasing which is a great sign.  This is no doubt caused by the smaller port diameter that these engines demand. 

 

In a street car, with an appropriate hydraulic cam and a decent two barrel manifold the thing would be a weapon and embarrass a lot of big dollar cars.It is a damn near perfect two barrel speedway head IMHO.  It shows the importance of porting to suit the purpose, not just porting for the sake of it. 

 

Your flow figures are near identical to my current E2 speedway head although yours has marginally better high lift figures as my E2 head has no intake runner mods as that was not in the design brief 5 years ago. 

 

This head with a TIGHE 392c on 110 lobe separation to ease the torque in, will be a great 2 barrel speedway package.  It will pull like a 14 year old from 2400 to about 5800 and then it will just be making noise, but sweet noise none the less.   His cam sounds close to 392c specs in lift and advertised duration but the centreline sounds a bit tight. 

 

Tell the owner to hold on as this thing will be a torque monster.  Well done.  Is this an alcohol motor?

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Okay so production is limited to 98 PULP but everything else is free, save for stroke.  This package will make some great numbers and provided the cooling system is up to the job it will be bad fast.  I think it will make more power than alcohol anyway as it wont have so much fluid to pass through the restricted manifold.  Will be interesting that is for sure.   

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In a street car, with an appropriate hydraulic cam and a decent two barrel manifold the thing would be a weapon and embarrass a lot of big dollar cars.It is a damn near perfect two barrel speedway head IMHO.  It shows the importance of porting to suit the purpose, not just porting for the sake of it. 

 

 

This right here is a huge compliment to me, cheers Tony. Yes you are correct that there is a big difference between just making a port larger for flow and making a port work properly using a smaller area and with a smaller valve, Once the head has the larger valve with backcut and a better seat profile there will be even more flow in it, I'm confident now that the shape of the port is correct for this combination so a bigger valve and better seat will only improve it.

I grabbed the carb he was using on his race car to compare the flow with the carb I modified, as it turns out his carb is a 350 based 350 with a modified metering block and that's it, on a stock 84da manifold with just the top of the plenum chewed out to match the adaptor for the holley, The head he was using was a C1 casting with no port work and the chamber opened right up so it looks like a hemi chamber to drop the comp with his flat top pistons and a single seat cut and stock valves with some double springs, he was running this with the cam I mentioned above and big 2in primary headers, he was always popping head gaskets everytime he got off the gas and then back on it. I've been told by other drivers that he is a great driver and a few years ago had a good engine and won quite a few races, then he damaged it and has just had reliability problems ever since and could never get the combination to work again.

So now he will have a carb that flows 58cfm more, a manifold that flows over 20% more and a head that will flow 208cfm at his lift point and will have 10.5 comp on 98 fuel. It should be a bit better ride this time and get him back towards the front so he can enjoy his racing again, He was just about to retire from racing before we got talking and now he is like a school kid again hahahahaha,

Duckboy his name is Robert Wolf and is a local bloke here in Albany WA

Wookie I don't know if you have seen it but in the DIY section on this forum I have a thread showing the build of my flow bench, This is the major tool I use to develop the manifold and head, the most important tool on the bench in my opinion is the velocity probe, it allows me to measure airspeed at any point of the port and I can map this airflow on the benches software and see were the air wants to flow and this guides me to the shape required for it to flow nice and smooth, the other things I use on the flow bench is cotton on a rod, when I put the cotton in the port it follows the airflow so I can physically see were the air is moving, it also shows me the airflows behaviour, the cotton vibrates when the flow is turbulent so you can place this anywere and you can see dead areas or areas needing work ect ect. Also when the air is moving through the port you can hear whats going on, turbulent air is very noisy so the sound is another tool to determine if your going in the right direction. Apart from that I have a collection of carbide burrs for alloy and cast in few different shapes and lengths up to 6in long shank. I use an air die grinder and a large compressor, a tip for porting is wear your PPE I have a full face mask with filters (cost me $400) long sleeve shirt, pants and gloves, the splinters from the alloy is sharp and when they stick in they sting, One in the eye and you done, as for cast iron and emory rolls the dust they produce isn't good for your health so that why I wear a full face filtered mask, I train in a sport that my lung capacity is very important LOL so health is important. I use a TIG for welding and all the other measuring tools to measure diameters and such, oh and a good flexible led light to put light in the ports as you work, that's about it hahahaha.

 

Next week I will do a test on a stock port with the 3 angle seat and just chamber work and see how that compares to the rest and add it to the list.

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Awesome work on this head.  Check out the low to mid lift improvements.  This head takes off like a rocket. Hello roller cam!!!

 

Thats funny cos I was thinking the exact same thing...It would look and idle like stock but totally haul ass.

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a tip for porting is wear your PPE I have a full face mask with filters (cost me $400) long sleeve shirt, pants and gloves, the splinters from the alloy is sharp and when they stick in they sting, One in the eye and you done, as for cast iron and emory rolls the dust they produce isn't good for your health so that why I wear a full face filtered mask, I train in a sport that my lung capacity is very important LOL so health is important.

 

This is something alot of people should take on board,always wear your PPE.You might feel like a dork wearing it at home when no-ones around but we all need to be thinking safety first.After a while you get use to it and it's benefits...

 

I wear riggers gloves,safety glasses,ear muffs,long sleeves and long pants doing any welding cutting/grinding jobs.   

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Duckboy his name is Robert Wolf and is a local bloke here in Albany WA

.

 

Ok I've never heard of him and I know or know of pretty much all the production sedan drivers, I take it he pretty much only does the local shows. I'll be over in WA again this season at Easter for the Modified Aus title in Albany, I was over there for the Production Aus title at Collie last season.

 

This is something alot of people should take on board,always wear your PPE.You might feel like a dork wearing it at home when no-ones around but we all need to be thinking safety first.After a while you get use to it and it's benefits...

 

I wear riggers gloves,safety glasses,ear muffs,long sleeves and long pants doing any welding cutting/grinding jobs.   

 

Stop making me feel bad, I wear a T-shirt, shorts and thongs (trackies and mockies for winter) for pretty much everything but occasionally I use safety glasses and the welding helmet. :o

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Next week I will do a test on a stock port with the 3 angle seat and just chamber work and see how that compares to the rest and add it to the list.

 

Here is my tip.  Modest low to mid lift gains but still slowing at 400-450cfm due to the restriction in inlet track, lack of bowl, short and long turn radius attention. 

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Tony I think you are spot on with your prediction.

Duckboy yeah wolfy only races locally mate, drop me a PM when your in Albany so I can come down and say hello. I Looked up the Albany speedway website and his name wasn't under the drivers list so I don't know what the go is there, maybe they haven't updated the website as he said he wasn't racing but has now changed his mind, He races a grey XF.

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Tony I think you are spot on with your prediction.

Duckboy yeah wolfy only races locally mate, drop me a PM when your in Albany so I can come down and say hello. I Looked up the Albany speedway website and his name wasn't under the drivers list so I don't know what the go is there, maybe they haven't updated the website as he said he wasn't racing but has now changed his mind, He races a grey XF.

If you really want to get your name out there you need to get your stuff on a car that races at more tracks around WA or even races nationally, there is plenty of guys that travel all over Australia with production sedans and Modified sedans. Over here the production sedans have races in Portland down the bottom of Vic all the way up to Maryborough in Qld.

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Cheers for the answer clevo120y, i have been reading your air flow bench thread too, i must say all of your posts are very inspirational.

All i have really done to my crossflow was clean up some of the casting lines in a manifold with my little rotary drill and rough them back up, might have to invest in a bigger set up as reading these makes me want to learn a lot more about the process and its great that youre showing us how you check your work to see that youre on the right track, thank you!

 

yeah safetys a big one, i used to go bare foot around most of my jobs, after months of treading on little wires from teh wire wheels and increasing my pain tolerance and possibly tetanus hah i had a lucky scare with a crossflow rolling off a tyre i placed it on [still chained up] and luckily stopping on the base of a engine crane with my ankle between it and the floor. boots for the big jobs now [if it ever happens again at least it wont scratch the shit out of my leg]. ive paid good money for laser surgery and always use glasses and ear plugs are a definite must with power tools if you want to hear in the future. PPE is pretty cheap and very accessable, i always have a stack to hand out to mates aswell, spesh when a few are giving me a hand, that way we all can look stupid together and enjoy a few beers instead of hospital trips hahha

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