ando76

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.

Okay then Slydog's pricing would be close to the money. They are a great set of pistons in my humble opinion and if I didn't have a brand new set fitted up to balanced and rod bolted rods I would be all over them. What oversive are the 250 rings?

I have used K&N oil filters on the race car now for two years and have found them to be spot on. I have no idea on flow rates etc. but they are used by NASCAR teams so that is good enough for me. Having said that, I change the filter every meeting due to running methanol so service interval is not that important to me. My bearings have shown no sign wear after a year of abuse and in the tough, dirty world of speedway and methanol - that tells me they are doing their job. I import them in bulk whenever I do a Summit order and with freight they work out about $14 a filter. Cheap insurance for a motor that is worth a lot more than that. I think that if you are buying a ryco filter and changing them and the oil regularly then you could not tell the difference in a street application. Clean air and fuel going in and more regular oil changes with quality oil would be more of a concern to me than individual flow rates.

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.

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.

The 250 oil rings won't fit the 200 rod pistons, if they are acl pistons that is. 250 pistons have a 4mm oil groove and the 200 have a 3mm. You can get a buick ring set and use the oil rings out of them as they are 3mm but the cost gets up as you are buying two sets of rings to make one. Well that was the case January 2012 when I had to throw rings at my speedway engine. Maybe Hastings or someone has made a ring set to suit the 200 rod pistons by now. I think the pistons are around $450 new from memory so probs somewhere around there. I just paid $80 for a set of Hastings rings to suit my ross pistons (same as acl 250 pistons). Hope that helps. What oversive are your pistons???

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.

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.

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?

my extreme top has the same dirt pattern above the carb after every meeting. tells me that it is getting the majority of the air from there. I run a modified K&N stub stack on my carb as well.

14" x 3" minimum and a k&n stub stack and extreme top filter for the win.

Zok - Zoran he is still around. I met him years ago when he did an engine and a carb for a friend of mine. Your flow figures are truly impressive considering that you have not yet touched the inlet swirl, although they are no where near as restrictive as the c2 swirl. There should be more gains to be had in the chamber. The multi angle cut is no doubt helping you. I got good flow figures from Jason's current c1 head with just bowl and chamber work on a single seat cut. I've just had Cam do his multi seat cut on another c1 head with a 1.84 inlet. I'll port it when I get back and then take it to the same bench I flowed the other C1 head to see what gains I can make. It will also have narrow neck valves so it will be interesting. Do you plan on doing a comparison with head flow figures with and without the manifold? I reckon your airspeed will be good with a well balanced, even flowing inlet manifold, so it will be interesting to see what drop - if any there is. A racer up in Cairns just fitted one of the new manifolds and he rang me to find out where his engine had gone. They thought they had wiped lobes off the cam the engine was so calm and happy. Shows what an even flowing manifold can do, even on a grumpy flat tappet motor. Keep up the good work.

202 cfm through a stock valve size is impressive. I bet the low lift figures are well and truly up there. If you have a set of internal calipers have a bit of a feel around in the inlet track. There is a choke down in there which reduces cross sectional area. What valve seat cut do you have and have you back cut your valves? Are the valves 'narrow necks'? Have you thought about tapering the inlet valve guide boss protrusion? I'll bet my lefty that there is another small gain in that little gem. Good to see the 6cfm gain from shortening the throttle butterfly screws. I always knew they were a restriction but to have it quantified gives me a warm inner glow. Yes I need to get out more. Keep up the good work and photos. I know at times it is a pain to take the photos and stuff as you are working but I, and probably a hell of a lot of others, appreciate the detail.

Another one converted to the virtues of a programmable ignition which provides good spark. Wait till you get a curve into it and then you will discover the true power of that little box. Why anyone would play with dizzy weights anymore is beyond me and the same could be said of locked timing IMHO, but each to their own I suppose. My old man always said "there is more than one way to skin at cat" but I like to add to that by saying "Yeah but I prefer to do it with the sharpest knife." Keep us informed of your progress please.

Just looking at the butterflies and noticed that the screws protrude a long way. Most people cut them off flush and then loctite the feckers in and centre pop the edge of the thread. small gains but they all add up. Have you tried a twin hole spacer over an open spacer to see the flow difference. You can also taper the two hole ones, similar to what they do with the aftermarket four barrel ones for good airspeed gains and better fuel metering.

If you had to charge your time what would that manifold be worth?

Good spotting Clint - wondered if anyone else noticed that. I'm going to pop an inlet valve out of it and check sizing and clean up a chamber and CC it. I'm thinking this head may be going to Brisbane with me for a bit of 'Cam magic'. I'm starting to wonder if the 'C ?' casting was removed at the factory. I have all sorts of stories of weird stuff happening at Ford where trial bits and pieces made there way into production cars by oops'ys.

Yeah but have a look at the depth of the chamber and the fact that the inlet and exhaust swirl don't go all the way to the head gasket face. Also look at the shape of the chamber just above the inlet valve. It's like no other head casting I have seen and it all looks factory not milled down as it is all still rough casting. I'll blast the chamber up one day and post another photo.

Clint I think it is just the light from the bench playing tricks with your eyes and the fact that the second shot it not at the same angle as the first. If you look at the first c1 shot at the first two cylinders you can see less of a taper. The first head came off a stocker so I don't think it has been played with at all prior to my playing with the valve shrouding. I laid the exhaust swirl back a bit to from memory, but just a touch. I reckon if I blasted the second c1 head chamber and laid them both on the bench at the same angle they would be the same. I have another two c1 heads here but they are both still attached to blocks.

saves me going into town and snapping a photo of my E1. thanks.

Early unmarked head chamber and now the mystery head chamber. The raised casting section has been dieground back, but dead set looks like C2 but this is no C2 chamber. Can anyone identify it?

I don't think so Clint. I have just laid back the inlet swirl. Here is another C1 head chamber - no where near as clean LOL and no laying back on the inlet swirl.

C2 Head chamber with laid back inlet swirl. (D,C2A are the same) Note how the chamber shaping goes all the way to the head gasket face. C1(C1A) Head chamber with laid back inlet swirl and reduced sharp point where exhaust and inlet meet. Similar to C2 but note how the chamber shaping stops short of the head gasket face. I believe that these heads have the best inlet flow potential and best initial chamber shape. With additional shaping on the opposite side to raised inlet swirl area and a bigger valve I reckon low lift flow figures would go through the roof. Cam and I are playing with this idea on my new speedway head. I'll get an E1 snap and then an unmarked head and we have pretty much got them all covered.

Leave it with me Matt. I have a pretty full on week this week but I will try and make time.

I've got an E1 head in my shed in town. I'll grab a chamber shot when I'm in there next. I have a cylinder here at home that has a chamber like I have never seen before. It came off a HM Gem engine and the casting number had been ground. It sort of looks like a C1 but with less of a rise. I'll clean up the chamber when I have time and post a pic. It is truly weird. Since I have all the head castings I should really take pictures of each chamber and post them up. Hmm time.....