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Clevo120Y

crossflow porting results

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Duckboy you are probably right and that may come at a later date, I'm a very understated sort of person, I don't want to talk myself up until I prove to myself that the work I do works, this arrangement with Wolfy works for me at this point in time because after spending all my money on the tools I'm broke hahahaha, this work I'm doing is a no financial cost to me deal, just my time as Wolfy pays for anything I want to try and he owns the local wreckers and I am able to get parts as I wish, I needed a couple of holleys to cut up and fuck around with so he gave me some, so really my research is costing him money at this point of time but I think it will work out for him in the end. I'm starting small and earning nothing at the moment but hopefully my work will prove itself and I can start earning some cash doing this for others.

Wookie it is my pleasure to share these things with everybody, I am happy to give some tips that people can try at home for minimal outlay that I can prove on the flow bench, I know what it's like to have zero budget LOL Hopefully karma works for me and I get some work out of this.

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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.

I wouldn't be wearing gloves when grinding, or cutting if it is an angle grider. Can be nasty.

 

I am new fan of saftey goggles, even just working under my dirt riden Falcon they are good.

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man I admire you for this thread (and others) your dedication into engine performance and efficiency is second to none, who else has taken the time to build their own flow bench just learn how to port heads properly (I know some people have access to such equipment but who really has their own at home)  its a real credit to your ability and dedication to doing what you love

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Yeah dead right Thom.  Its a great effort and the fact that he is willing and able to share with us all makes it even better.  Kev Wyatt, the mechanical engineer I put up there with God, always says 'if you are porting without a flow bench then you are just playing with yourself".

 

He is right, yes there are some talented people out there that have done that many heads that they don't need to flow bench every change, but they all started the way Clevo120y has. 

 

Don't worry man you will get plenty of work out of this.  My only suggestion would be to send your head off to an independent flow bench for testing so that you can compare your results with theirs.  I know the bench I use flows 10cfm below 'bought/name' benches, so I always factor that in.  Just a thought.  Keep up the great work.

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Cheers Thom and Tony, I have enjoyed sharing especially when you guys show so much appreciation and give great feedback.

I have ported heads on a mild scale for a long time and only had seat of the pants judgement on if it goes better, Porting without a flow bench you really are just guessing, you can have an educated guess and make improvements for sure. Once you use a flow bench you start to find out what was just a waste of time, some of the things I've done in the past didn't hurt flow but didn't improve it either and once I started mapping the port velocity it really only took small changes to the port shape to make a big difference, simple things like throat percentages, blending the seat into the throat and the seat itself are all things that can be done that will give good results without needing a flow bench, plus I will be sharing things that you guys can do at home that I will prove on the bench before posting them up, plus things that I can show don't work to save people some time and money. 

Thanks guys for your interest and positive comments, I have shared things on other forums about what I'm doing but not to the same detail as here as I think this group is the best of the lot :) and I feel the urge to take the extra time to share the details with you.

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Ok I got the cam details today

Intake:

cam lift 325

lobe centre 105 deg

adv dur 305 deg

50 dur 251 deg

lash 20thou

adv timing op47 btdc  cl78 abdc

50 timing op18 btdc cl52 abdc

 

Exhaust:

cam lift 330

lobe centre 108

adv dur 308 deg

50 dur 254 deg

lash 22 thou

adv timing op80 bbdc cl48 atdc

50 timing op55 bbdc cl18 atdc

 

doing the calculations with a 10.5 static comp I get a dynamic comp of 8. the manifold is still the restriction, it drags the volumetric efficiency down to 91% and calculates a peak hp of 270 and torque around 250ftlbs.

Piston cfm demand peaks at 245cfm and I'm nowhere near that, with this cam if I could get the head and manifold to flow 245cfm together it could produce just under 400hp.

I need to get working on manifold series 2 LOL

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Only on paper and the calculator does the manifold drag it down.  The great low lift figures will trick the manifold into flowing more is my tip. 

 

That cam is a okay for speedway 2 barrel applications.  I would have gone for a wider lobe sep to soften the torque delivery and I don't like the exhaust duration being longer than the inlet, should be the other way around to give more time for the air to flow through the manifold restriction.  The inlet also opens later than a 392c but each to their own.

 

Has the owner run this cam before?  If so did he like the way the power came on etc. 

Keep up the good work. 

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I agree I would like a 108 lobe centre and it to be a single pattern, more separation would of given me a couple of more degrees in the overlap which I would of liked as well, I am going to keep the smaller exhaust valve now with the bigger inlet valve, the ratio will be under but I think this is the way to go to keep the exhaust flow under control. Wolfy has been running this cam for years and when his engine was reliable he performed well and he liked it, in saying that I don't think he has had a properly thought out combination under his right foot looking at the parts on the engine he has, that will hopefully change very soon and he keeps asking me if this new engine will scare him hahahahaha, that's all he wants LOL.

I'm thinking the horsepower will be about the 270 range and the torque will be about right as well, what the calcs don't show is that I think the torque curve will be a big flat line throughout the rev range which is what we want, our tracks down here I believe are of the shorter type so torque will be king.

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Just tell him he needs a 392c on 110 lobe separation.  Best $340 odd he will ever spend.  Add a bit extra for a some quality isky so-382 lifters and then he will be scared.  270rwhp on petrol might be a stretch with that other cam but you never know, I've been wrong before today.

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More lift and tighter lobe sep will really hurt that package on a two barrel but Rob.  The one they have is pretty close to ideal and with the new head and carb old mate will get a nice kick in the pants.

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I just know this stuff yodda.  Nah I just guess.  I'm a backyarder after all.  well enough thread highjacking.  should have my new head flow figures by the end of this week.

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No it's not,it's a perfect opportunity to compare cams on what you think should work with a flowed head to what the customer or other people think work.The result will be knowledge for everyone and Clevo is showing us which soooooooo many people try to keep secret.

 

What people have to remember is the purpose of this head/engine combo not power and as it's for speedway it needs a WIDE FAT rpm and torque band where as I can live with a band of 5000-7200 for my purpose.This speedway combo in a street car on a 4 barrel and manual (insert really good driver here also) or stalled auto and gears would win more than it lost on the street for sure.

 

It's all info and in the right context as far as I'm concerned with full acknowledgement to the OP for his awesome write up and time to help us as you have Ando...Keep it coming for us plebs you pair.  

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Make sure you post up your results Tony.

Sly now that the head flow to 600 thou I want more lift hahahaha, I wish I could use a roller cam in this class.

I flowed the port with the manifold on and it still only flows 162cfm so the topend of the lift flow is wasted but all of the low and mid lift is still a bonus and will produce that fat torque curve I'm after.

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Make sure you post up your results Tony.

Sly now that the head flow to 600 thou I want more lift hahahaha, I wish I could use a roller cam in this class.

I flowed the port with the manifold on and it still only flows 162cfm so the topend of the lift flow is wasted but all of the low and mid lift is still a bonus and will produce that fat torque curve I'm after.

 

 

As it should the number's skyrocket from nothing super fast.

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Thanks Dave, how did you go with your head?

Tony I'm just a baggy arsed sparky playing around in my back shed too mate, sometimes that's were the best work is done :)

Sly I've been given the go ahead to test the car on the track in a test and tune session when it's up and going so I can feel what it goes like YEEEE HAAAAAAA!!!!! I've never driven a speedway car so the wall might see some action hahahahaha

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And your spot on Sly that this combo with your manifold and carb that your selling could go 350fwhp, remember this head isn't finished yet, it has a bigger valve and seat work to go as well as matching the cross sectional areas, I don't want to make claims ahead of testing it but I'm confident of it supporting 350hp no worries.

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Make sure you post up your results Tony.

Sly now that the head flow to 600 thou I want more lift hahahaha, I wish I could use a roller cam in this class.

I flowed the port with the manifold on and it still only flows 162cfm so the topend of the lift flow is wasted but all of the low and mid lift is still a bonus and will produce that fat torque curve I'm after.

 

I will post flow figures as soon as I get them.  The head is getting flowed down here (Brisbane) so I will not be comparing apples with apples but it should be close.

 

The manifold restriction is the issue and the reason to stay well below .600" lift on these packages.  The springs needed to run over .600 are just a waste of pushrod effort and hurt horsepower like you would not believe. This is an area that people often overlook in making power and torque.  Bigger is not better.

 

I can speak to Mark and see if I can get a manifold for you real cheap so that we can do some serious flow bench testing on it if you are interested?

 

On the subject of cams would be interesting to contact the cam companies and see if you could get a flat tappet grind to suit those low lift figures.  Something with the most aggressive ramp rate possible on a flat tappet cam would be good. 

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