I have personally seen the numbers this motor made on the dyno. It has a super lobby cam i dont know what carb but it was a demon with double pumpers brand new and ported heads i think they were gt40p's this guys dad built it up and didnt spare any expense they are loaded$$$
I would definitely like to see the whole combination. I'm not saying I don't believe, it's just that a n/a 289 even with AFR 185s would be hard pressed to hit 500hp, much less wearing iron GT40Ps. Now maybe if that 289 was really a 347 or bigger stroker.... Guys have been known to not tell the whole truth about their engine's displacement or if there's a hidden nitrous bottle somewhere . With a Dart block I think you can get something like 370+ cubic inches. Then 500 hp becomes almost easy. Since hp is a function of torque and rpm, and most little motors don't make much torque, you have to have lots of rpm. Hence my comment about turning 10,000 rpm.
It might not have been here, but other forums it tends to happen. I've had more than one person recommend I port a set of E7's for a cheap upgrade. I agree with you, stock Ford heads pretty much suck, but most of them on our cars are no worse than the late model 5.0.
I have heard that recommendation a couple times on this forum, and for the life of me, could never figure out why they recommend heads that are just a bit better than our stock heads. If you are going to swap heads, swap with something that will give you a good boost, not just 10 more HP... I swapped to GT40Ps, and despite a couple of "issues" I had to deal with, all involving spark plug-to-header clearance, they were a WONDERFUL boost (we argued to a point of maybe 50 HP improvement on one thread, MAYBE!). I would go the 40 non-Ps if I did it again, just because of the plug fit issue (with headers, no problem with stock exhaust manifolds). Next time, I will go AFR 185... I have seen the flow numbers, and the 351 heads and the E7s just don't compare to the 40s...
why does anyone want the 351w head anyways you lose compression and the chamber is junk just stick the 1.84/1.60 valves in to the small chamber heads and port them out .. you wont notice anything different except the higher compression rump vrs the bogwater compression the 351s make
Wtf? When did 2cc cause a "bogwater compression"(?Whatever that is?)? The early W heads did have an issue with a really restrictive exhaust port, however that was a lump of iron that, when removed, takes the exhaust port from one of the worst in Windsor history, to one of the best. The ports and valves in that head are the largest, while the chamber is only 60cc. If you get the 4v heads, they are around 58cc, which is what the 302 chambers are. I suppose you are talking about 289 heads when you refer to small chambers. Well, with those small chambers you get small ports, small valves, shrouded valves, and no real way to make things better. You can install up to 1.94" valves, however they are seriously compromised by the small chamber keeping them shrouded. You can port, however there is less meat in the ports to open them up compared to the W heads, which start out bigger anyway. You can mill the W heads, if an extra 2cc bothers you, and/or you can use a thinner head gasket. Over 9:1 on iron heads, you have to run premium fuel. Over 10:1 and you are retarding the timing with iron. So why try to use small, restrictive chambers? Don't get me wrong, I have used the early 289 heads and got plenty of power from them with 1.94/1.60 valves and lots of work... Looking back though, I would have done much better putting that effort into a set of W heads. As for the GT40p, sure it flows great... outflows the W head because stock for stock, the W head sucks. The W HAS to be ported! Once it is ported, it is far and away the best stock head casting. No one here would look at the stock exhaust port and think the head was any good, that is how badly they have it restricted. But that restriction is solid and the hole is big, so grind it and you got a good thing. Even if someone could show me documentation that the P head is better than the W head, I would still ask if the tiny amount it would be was worth all the trouble with headers and plugs...
i wish i would have found a flow bench for my C9 heads , cause ill tell you right now after havin them ported....they look huge and smooth...i would put them up to any P head...or any other factory IRON head...yes the exhaust hump is big the early c9s but you CAN PORT THEM ... ill be sure to tell everyone how good my C9 are when i get my mav out. this is a guesstimate(thanks Dave ) on my engine: 396 hp @ 6000 rpm with 231 average 378 tq @ 5000 rpm with 286 average if those numbers are close thats not half bad for a basicly stock 351w with some cam and C9 heads
I can't wait till you get that thing running! You need to get it on a dyno after it has broken in decent.
Ported heads is a whole different ballgame. I've done some rough work on my 77-78 heads, nothing special. Disposable test heads are good for porting. I got no problem with Windsor heads, but they are small compared to Chevy. Decent aftermarket heads just level the playing field. Another thing, know your weaknesses, you can compensate for crappy heads to an extent if you know exactly what you're dealing with. Its certainly cheaper to get a dual pattern cam and port the exhaust than a set of aftermarket heads for a daily driver.
Fyi http://powerheads.com/SB50.html Also, check out the early heads. http://powerheads.com/sb289.html
Kinda hate to beat a dead horse here, but since this thread kinda got resurected, I think i'll address the orignal topic. Horsepower ratings were underrated by the factorys so thay could cheat at racing. I know NHRA and I think NASCAR both factored vehicle weights according to factory horsepower specs in stock classes. When Mopar made the hemi, they pulled the horsepower number out of thin air, and it was rated close to 100 horsepower lower than it actualy made. Ford and Chevy did this with their motors too. Kind of an interesting tidbit.
True, but did you know that when chevy made the 400 SBC they rated it at the 1 Hp per cube and that was correct the Hemi was rated at around 400 Horse and made over 600 Fords 427 made over 600 so there is quite a bit of truth there
