Clevo120Y 815 Posted December 21, 2013 Well I have the pleasure and opportunity to develop a head for Chris's Cortina, already a very serious engine and produced very good numbers already. He sent the head and aussiespeed manifold down and I run some flow tests and took some pics for comparisons of before and after work, the head had already been ported by someone else and I was keen to see what he had done, the port flows OK but I'm very confident of finding some good gains throughout the lift range. The valve sizes in the head are 1.84in intake and a 1.6in exhaust and we will stick with those sizes, unfortuanetly the valves and springs in the head weren't what he was told they were, the valves in the head were an EVL 3 groove item for both the intake and exhaust and the spring pressures were measured at 114lbs seat pressure, Chris was told differently and lead to believe he had better quality items installed, also the springs were installed with a flat washer shim which I don't recommend, either an internal or external locating unit should be used. The valve seats are a form I personally wouldn't use, they are a 45 seat with a radiused bottom cut, I prefer multiple sharp angles for better fuel atomisation and flow at the valve seat so this will be recut also. Intake Flow figures for this head are 50 28.37 100 58.21 150 92.13 200 117.51 250 143.38 300 166.34 350 181 400 193.51 450 198.82 500 203.6 550 199.19 600 198.18 650 196.5 The main problem with the results are they start to fall over well before Chris's cam lift of 600thou. As I said the results are OK but not as good as I was expecting before I got the head. The Exhaust port is untouched but I will do a little work in there also. The other things that let the job down is poor match porting to the head with both the thermal insulator and also the gaskets hang in the port etc etc, it's just little details but they are the things that matter to me that show pride in a job. Anyway that's the past and we are looking forward with a few upgrades with the head and work on the manifold as well as a new set of headers Here are some pics of the head and I will start work on this in the new year. 1 winton reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted December 21, 2013 Good thread bro...Good to see the approach of your quality control.Chris's engine did make some very serious numbers which shows the promise in the 250 aswell so your work will only compliment that. Have you guys settled on a cam and style yet...IE roller or solid? Keep the updates coming and good luck with the rest of the work. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
revhead 1,392 Posted December 21, 2013 wicked piccis bud ,i generally red paste when i do my own port matching and like you i hate gasket over hang 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted December 21, 2013 That valve seat is a joke in a performance application. anyone who is anyone knows that the valve seat is where the most gains in airspeed are had. The head seems to have had a lot of work on the high speed side but the mark from the gasket shows that there is a big step on the low speed side - I like a step there but only about 1mm. that looks to be 2mm or it could just be that the gasket is not locating properly on the port face. The cross sectional area just past the bowl looks out and the short turn doesn't look that good - bit hard to tell from the photos. The flow figures are also not that impressive - but that could also depend on the money outlaid for the port work and I guess that is what is important to remember here. I don't know what the head cost or what the design brief was so I shouldn't sledge to hard BUT simple things like valve spring locators, correct valve spring tensions, valve seat cut, 'port matching' and giving the customer the parts that they paid for SHOULD be a given. 3 revhead, Clevo120Y and slydog reacted to this Share this post Link to post Share on other sites
PRO250 1,506 Posted December 22, 2013 Good read those number taken at 28 or 32?Its amazing how much numbers can be made with such a basic head I got told by who that has not been named that he did 340fwhp with a head that flowed 2cfm more then a standed head. funny most engines get there numbers out of a good heads these engines make numbers just cause they look cool in cortinas 2 slydog and Clevo120Y reacted to this Share this post Link to post Share on other sites
Tyler06 266 Posted December 22, 2013 That valve seat is a joke in a performance application. anyone who is anyone knows that the valve seat is where the most gains in airspeed are had. The head seems to have had a lot of work on the high speed side but the mark from the gasket shows that there is a big step on the low speed side - I like a step there but only about 1mm. that looks to be 2mm or it could just be that the gasket is not locating properly on the port face. The cross sectional area just past the bowl looks out and the short turn doesn't look that good - bit hard to tell from the photos. The flow figures are also not that impressive - but that could also depend on the money outlaid for the port work and I guess that is what is important to remember here. I don't know what the head cost or what the design brief was so I shouldn't sledge to hard BUT simple things like valve spring locators, correct valve spring tensions, valve seat cut, 'port matching' and giving the customer the parts that they paid for SHOULD be a given. I can tell you now that head cost me $1950 plus parts and 2 date it owes me $3500 and thats with 2 different people working on it not just one. I am extremely saddened by wat it flows but I should say I have always known they were multigroove valves but I was under the impression I had 1.86in and 1.56 ex. The work Shaun is doing now coupled with all the new valve train will make it an easy $4500+ Head but with the power it made before coupled with the new work it shall be singing. A big thanks to Ando76 as well who is providing help and advice in the background. Sly im gonna stick with the same solid cam. I really loved the way it drove and sounded before. Hopefully the EDM lifters will help it last this time around. 1 slydog reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted December 22, 2013 Um I don't know what to say to that Chris except sorry to hear. At least this time around it will work and with the Isky lifters you will have great, consistent oil pressure and no worn lobes. Share this post Link to post Share on other sites
Tyler06 266 Posted December 22, 2013 Um I don't know what to say to that Chris except sorry to hear. At least this time around it will work and with the Isky lifters you will have great, consistent oil pressure and no worn lobes. Perfect thing to say dude. For an engine that has made the power it has the only thing that has let it down is consistent bad oil pressure. Hoping for an engine that lasts more than 800kms this time which is its record not to mention the looks it gets from 60k cars that get blitzed lol 1 Jonathan Mark Davidson reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted December 22, 2013 Tested at 28in Dave. I don't believe that Chris has got his money's worth but we will fix that for good now and power on 1 Jonathan Mark Davidson reacted to this Share this post Link to post Share on other sites
ando76 4,354 Posted December 22, 2013 212@ 500 here we come....... 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
NZXD 2,328 Posted December 22, 2013 What sort of power is this expected to make or estimated 1/4 times? I'm really interested in this thread, keep up the good work. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted December 23, 2013 I would hope to see very close to 300hp at the wheels and just crack an 11. Share this post Link to post Share on other sites
matt_lamb_160 252 Posted December 23, 2013 Those numbers are pretty good up until 0.5" lift and with a basic tidy up will be even better (compare the 0.35" lift with some others here). Value for money may be questionable, but don't be too disappointed Chris. Also remember that the cam should lift beyond the peak head flow figures (because you are not at max lift for long) otherwise your cam is too small. The step at the bottom may be fixed by making sure the manifold is all the way up when you bolt it on. I wouldn't be taking too much material from that area, you'll end up with massive ports for little gain. I am sure it will come out great. If you guys get 212@0.5" without a big cross-section and can maintain it to 0.6" it'll be a weapon. Share this post Link to post Share on other sites
ando76 4,354 Posted December 23, 2013 your spot on Matt re Cam and peak lift and not destroying the low speed side. Clevo120 got 212cfm @500 with his speedway head (xflow porting thread) so I'm sure his rework of Chris's head will go as good if not better. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
matt_lamb_160 252 Posted December 23, 2013 I am sure it will be great, can't wait to see the results. 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Lord_fahrquhar 2,580 Posted December 23, 2013 Gentlemen, Fucking loving this thread. Go hard! 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Mixalis 266 Posted December 24, 2013 Good on you Shaun keep us updated mate! 1 Clevo120Y reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted December 24, 2013 Thanks guys, if the port doesn't go 212+ I would be very disappointed. My approach as always is looking for port stability, I believe that when a port is stable the flow figures will follow. Also I personally think that attention to the manifold will be the big payoff. I will be starting this head just after new years and I will keep you guys updated. 1 Crazy2287 reacted to this Share this post Link to post Share on other sites
P100_Ute 460 Posted December 27, 2013 Hoping for an engine that lasts more than 800kms this time which is its record not to mention the looks it gets from 60k cars that get blitzed lol Fingers Crossed its a constant runner after this and no need to do any rebuilds. I do about 800km's a week in my Cortina. And this fastest/reliablest/daily driven Cortina award that i been carrying is getting bloody heavy. Come take it off my hands Chris. Mine let me down a bit today, heater core went and spilled coolant all over the road in Mandurah. whipped out screwdriver and plumbed the in/out hoses into each other.. and looped the heater onto itself. slipped into supercheep for coolant. and hey presto problem solvered. Dont even know why i plumbed the heater into the equasion.. i never used one in my life in a Cortina. Share this post Link to post Share on other sites
Lord_fahrquhar 2,580 Posted December 27, 2013 Ya bloody don't need it in wa! 1 slydog reacted to this Share this post Link to post Share on other sites
slydog 7,873 Posted December 27, 2013 There's a challenge bro Share this post Link to post Share on other sites
Clevo120Y 815 Posted December 28, 2013 Fingers Crossed its a constant runner after this and no need to do any rebuilds. I do about 800km's a week in my Cortina. And this fastest/reliablest/daily driven Cortina award that i been carrying is getting bloody heavy. Come take it off my hands Chris. Mine let me down a bit today, heater core went and spilled coolant all over the road in Mandurah. whipped out screwdriver and plumbed the in/out hoses into each other.. and looped the heater onto itself. slipped into supercheep for coolant. and hey presto problem solvered. Dont even know why i plumbed the heater into the equasion.. i never used one in my life in a Cortina. Challenge accepted Tim LOL when you eat Chris's dust then I can do the work on your new setup to catch up again hahahaha 2 P100_Ute and PRO250 reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted December 30, 2013 So out of interest I flow tested the thermal barrier spacer from aussiespeed that goes between the head and the manifold, 215cfm it flows at 28in, this is great for everyday to mild engines but starts to be a restriction when you start chasing more power, I will be opening it up just slightly to flow a bit more but still keeping the airspeed up, the trick is to open it just enough to flow enough for the purpose plus a little head room, the joys of having a flow bench, I can open it up to flow 230cfm without making it too big. I will be doing this for both Chris's and Slydogs spacers. I know that Slydogs was used on another engine and would have been a restriction to his head flow figures. 1 slydog reacted to this Share this post Link to post Share on other sites
Clevo120Y 815 Posted December 30, 2013 Cracked 500 posts I must talk too much LOL Share this post Link to post Share on other sites
ando76 4,354 Posted December 30, 2013 so how much material will you be removing from the high speed side of the spacer - my guess would be .040 - 060" and probably .020 from the low speed - but I'm just an amateur without a flow bench. lol. keep the posts coming. What is the diameter of the port of the spacer out of curiosity??? Share this post Link to post Share on other sites