XFGHIA747 76 Posted January 28, 2014 hey guys as some of you know im in the process of building a mild 393 stroker clevo just woundering what kind of flow figures are 302c 2v closed chamber heads stock and what kind of flow would i be needing? and is it achivable from the good ol cast heads with little work? cheers guys hopefully things will be good. Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted January 28, 2014 cheaper to buy AFD 2vs by the time you put it all together, and they'll out perform the cast iron 2vs 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
NZXD 2,328 Posted January 28, 2014 Standard 2v Cleveland heads flow around the 200cfm at .500. If you're building a serious 393 id be going for a set of alloys. Share this post Link to post Share on other sites
gerg 10,871 Posted January 28, 2014 Clevo120Y has done some great work and has flowed a set and got a bit less than that from stockers if I remember rightly, but a ported set might get 400 hp if done right. Most alloys will beat that out of the box, and you can run an extra point of compression over stock. Share this post Link to post Share on other sites
KRUPTOR 929 Posted January 28, 2014 A couple of mates of mine,runs 2V closed chamber heads on there 351's.One is in a XT falcon 351 compression is around 11.1 mild port job,i think standard valves heads milled etc makes roughly 400+hp at flywheel.Other is in an XC sedan 351 makes 475hp at the flywheel,but the 2V's on this have had abit of work with 4V valves rollers,port job etc. But when going bigger you need better. Share this post Link to post Share on other sites
XFGHIA747 76 Posted January 28, 2014 Thanks for the input then guys will be going alloys then was just testing my luck im chasing around 500 fwhp so like you said xcsedan the money ill put in to achieve that power from these heads ill just get alloys. Any recommendations on what's been used and what to stay away from ? Share this post Link to post Share on other sites
xdwagooon 46 Posted January 28, 2014 ive got a nice set of chi 3vs, they seem to perform well but ive got the 225cc I believe which is probably a bit overkill but their smaller ones work a treat Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted January 29, 2014 CHI 208s or AFD 2V's would be the way to go. hyd roller cam, should see you well into 500hp. Share this post Link to post Share on other sites
XFGHIA747 76 Posted January 29, 2014 Thank guy I like sound of the chi208"s, now I was planning running solid roller. Or go hyd roller? Also I just found out that the heads on the 302 are 4v does this change anything to specs and flow or still go the alloys? Share this post Link to post Share on other sites
Thom 6,654 Posted January 29, 2014 Go for the hyd roller especially, my old mans car had a solid but not one set of lifters made it past the 30,000k mark just swapped to a hydraulic roller Share this post Link to post Share on other sites
gerg 10,871 Posted January 29, 2014 Hmm a 302C with 4Vs sounds a little suss, I wonder what kind of engine it was... If that's the case, would be a screamer with no bottom end balls. Makes one wonder if they actually are 4Vs. Do you have pics of them? How did you identify them as 4V? You could reach that power goal with 4Vs with a little work, but even then alloys will still be better all-round. Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted January 29, 2014 if they are 4Vs, sell them and put them towards the alloys. worth it. definitely go hyd roller at that level of perfomance, next to 0 maintenance, reliable, etc CHIs or AFDs will be much of a muchness, AFDs in stock form will perform above 600HP and are cheaper, CHIs are a better head, but john hasn't owned the company for at least 3 or 4 years now.... which means after sales service from Dave at AFD is definitely better, and i give him high raps from dealings in the past. Share this post Link to post Share on other sites
ILIED 316 Posted January 29, 2014 They are prob 2Vs with 4V valves. Common as fuck mod back in the 80s and 90s.I have a couple sets of them. They flowed 450hp. 1 XTREME KARTS XF reacted to this Share this post Link to post Share on other sites
XFGHIA747 76 Posted January 29, 2014 well this shows my experience with clevos lol im a crossflow man i would know if the heads are off of course but on with the manifolds i cant it says its a 302c - 4v on the emissions tag in the bay thats was just my assumption that they were 4v but like i said im a crossflow man this is all new to me. but buy the sounds of things ill go the alloys. if they are 4Vs, sell them and put them towards the alloys. worth it. definitely go hyd roller at that level of perfomance, next to 0 maintenance, reliable, etc CHIs or AFDs will be much of a muchness, AFDs in stock form will perform above 600HP and are cheaper, CHIs are a better head, but john hasn't owned the company for at least 3 or 4 years now.... which means after sales service from Dave at AFD is definitely better, and i give him high raps from dealings in the past. thanks for the recommendations man will take a look into the afds then if there a good but cheaper option, i dont wanna end up spending money not needed if the hp is allready there, ill still be checking the heads that everything is right and port matching so will make good power, any recommendations on a inlet manifold that will still make my 500+ mark and shut the bonnet with out cutting it on the top side ? Share this post Link to post Share on other sites
ILIED 316 Posted January 29, 2014 RPM AirGap.Bout $400 As for the 2V/4V thing. Is there a serious gap between the valves? If its only like 2mm, they 4V valves in there. If its like 6mm, the 2V valves. If each pushrod has individual ones through the head, its 4V. If some share a big hole, they 2V heads. Share this post Link to post Share on other sites
XFGHIA747 76 Posted January 29, 2014 cheers man well soon as i get the donk out and the manifolds off will know what they are, just thought it was strange it had that 4v thing on the emission tag lol. Share this post Link to post Share on other sites
bear351c 10,273 Posted January 29, 2014 4V's have the same amount of material above and below the inlet port. 2V's have 2x as much at the top. Share this post Link to post Share on other sites
NZXD 2,328 Posted January 29, 2014 If it says 4V on the emissions tag, ill bet my left nut it means 4V = 4 venturi = 4 barrel carb. The 302 clevo that came out of my XD had "4V" on the emissions sticker, in the workshop manual, just means 4 barrel carb. I honestly would spend any money on them, the comp with cc on a 351 can get up around 11.1, so on a 393 its got to be 12.1. If you're serious about getting 500+ hp, you need to spend money! So do it right, do it once and get some alloys that will make the numbers straight up. 1 MNTL.XD reacted to this Share this post Link to post Share on other sites
XFGHIA747 76 Posted January 29, 2014 I wouldn't bet my nuts on anything man lol, but good call makes alot more sence, and yeah well thats true save the hassle and if you want to get more in feature then you know you have a head to support it ay. Share this post Link to post Share on other sites
Thom 6,654 Posted January 30, 2014 By the time you reco.the head, machine for screw in studs, buy valves retainers and collets theres you money for a pair if alloy's Share this post Link to post Share on other sites
ILIED 316 Posted January 30, 2014 I agree.Reco of the heads would be about $1500.New CHI 2V (which flow VERY similar to 3Vs but still take shelf 2V manifolds) are $2800 and flow much more and are alloy so not they're not just lighter, but they will take a little more comp and the already come ready for stud mount rockers. All you need then is a rocker kit and guides 1 Thom reacted to this Share this post Link to post Share on other sites
NZXD 2,328 Posted January 30, 2014 I've only got a baby 302 Windsor, but when it came to head choice I was going to recon a the factory set of gt40p heads, which flow pretty average these days at 185cfm, but by the time I priced it all up, I basically had to spend only a few more bucks to get alloys that flow a significant more air/fuel. You won't regret the money being spent. Share this post Link to post Share on other sites
XFGHIA747 76 Posted January 30, 2014 Yeah thanks for the advice guys much appreciated will certainly go a GOOD set of alloys then, i better get saving these next few weeks want them and crank by june, what would you guys suggest for a comp ratio?? i was thinking into 11.1+ ?? Share this post Link to post Share on other sites
Trev Vaa 1,185 Posted January 30, 2014 if it were me personally, i'd go AFD 2v heads, AFD 2v manifold. the AFD manifold suits the higher port of the AFD heads, and is plenty good down low (surprisingly) dave does packages every now and again, contact him and ask, very easy to deal with, and if you ever need work done on the heads, he's always more than happy to help. http://www.airflowdynamics.com.au/index.html contact Mal at Camtech regarding the camshaft, trust in what he says, the guy know's his shit, he'll probably reccomend the CT2021 - 49901 - 110 it's a hydraulic roller, awesome cam fairly mild too. would be awesome with the off idle torque of a 393, should surpass your 500hp want too. CHI 2v's are ment to all work with factory extractors and intakes, but i can tell you right now they're a mile off, same as the AFDs, also a few members will remember when Scott tried to fit the CHI 2vs onto his 383 and spent ages trying to make everything match up perfect, so be prepared for that. Share this post Link to post Share on other sites
FORD_MAN 1,026 Posted January 31, 2014 Tho the down side is AFD 2V intake wouldn't fit under the bonnet cast heads can be ported to suit 500hp on a 393 but your looking at around $1000 just for CNC porting. if your rich you could look in to Scott Cook SCM 2V's. Share this post Link to post Share on other sites