Just wondering?

[holdtherice 0]

Hey guys, I've got a 69 sportsroof with the original 302 in it. It was rebuilt by a ford dealership in 2000 by the previous owner and now has long tube headers, a mild cam, and thrush racing dual exhaust. But it still has the original 2 barrel on it:sleeping: . My dad has an edelbrock performer manifold and a holley 650 on another 302 that he said I could have, and I'm hoping with all the other stuff it has, a 4 barrel will open up some power.

 

So my question is, about how much horsepower do you think my car has now, and how big a difference will the 4 barrel make?

 

Thanks in advance.

[Pakrat 1,043]

Hey guys, I've got a 69 sportsroof with the original 302 in it. It was rebuilt by a ford dealership in 2000 by the previous owner and now has long tube headers, a mild cam, and thrush racing dual exhaust. But it still has the original 2 barrel on it:sleeping: . My dad has an edelbrock performer manifold and a holley 650 on another 302 that he said I could have, and I'm hoping with all the other stuff it has, a 4 barrel will open up some power.

 

So my question is, about how much horsepower do you think my car has now, and how big a difference will the 4 barrel make?

 

Thanks in advance.

 

It's really hard to say maybe around 275 at the wheels give or take 15 but there is no question you should do it. The recipe for really waking up any engine particularly a 302 is just that, headers, cam, intake and a 4V carb, mine has a 600cfm Holley which is just right for the engine size and the difference is night and day.

[stangme 105]

Well that setup "originally " came with 220 screaming horses at the wheels with the 2 bbl carb, and like Pak said, with the headers, newer cam and exhaust, your getting the air to flow better which should be giving you some additional hp, the parts your talking about should help you some too, question is how good a job did the dealer do with the rebuild, and what would you like to end up with. I'm sure someone who knows engines and 302's in particular better than me will be able to give you some better info on what to expect, but I think you should end up in the 275 to 290 range when your done.

[holdtherice 0]

Thanks alot guys, the engine runs excellent right now and seems pretty strong for a stock 302, they seem to have done a good job rebuilding it. Those numbers were pretty much what I was assuming but I just wanted a few more opinions.

[Pakrat 1,043]

The biggest mistake most people make is over carbing, more is not always better. If you can't get the air out then there is no point in it going in. My cam isn't radical but it's not so mild either and with the prior stock dual exhaust size and glasspacks I think the one time I dynoed it I was in the 280's round about, I'll have to see if I can find my old sheet somewhere. When the restoration is done I will now have a 2 1/2" Magnaflow exhaust with X pipe and a Ram Air effect so I just may need to up my carb size a little, we'll have to wait and see. I'd really like to get in the 300 range (325 is my nice "I'm happy and content target") but I doubt that would happen until I also swap out my old 3spd manual for a 5spd.

 

I'll say one thing though, unless you are racing actual HP isn't always everything. With my glass packs I used to get some punks in their ricers at a red light every now and then give me a little throttle with their whiney coffee can exhaust like they wanted to race but when I revved my car with that whomping thump they used to swallow their adams apple and just smile with a thumbs up. Some of them probably could have taken me as my car was set up as more cruiser than bruiser but it's amazing how many folks equate a mighty sound with HP. LOL.

[holdtherice 0]

I was curious about that, I definately don't want to over carb it, but a free 650 versus a new 600 is definately easier on my budget as a 16 year old. Do you think the 650 would be so overboard that it couldn't be used with some different jets, the other engine it was on ran great, but I'm not sure of what it had done to it.

[Pakrat 1,043]

I was curious about that, I definately don't want to over carb it, but a free 650 versus a new 600 is definately easier on my budget as a 16 year old. Do you think the 650 would be so overboard that it couldn't be used with some different jets, the other engine it was on ran great, but I'm not sure of what it had done to it.

 

For the base line peformance mod you described I think the 600 is just right but 650 is not overboard by any means, especialy at a bargain. I personally wouldn't go any larger though but many others have so I would not sweat it. If I find down the road that I need a little more and you find that you need less we could always consider a swap as my 600 is a Holley too. :)

[Spoofty 10]

600 would be better. But as long as it's a vacuum secondary it shouldn't hurt too much.

I'm running a 650 with fully ported head, singe plane intake, huge cam and I run it to 7000 rpm.

According to the usual calculation I only need 630 cfm.

 

I found this guide at Holley.com.

http://www.holley.com/applications/CarburetorSelector/CarbSelection.asp

[Protowrxs 111]

Heh.. that's a nice little web app there.

 

True the vacuum secondaries can help with over doing the carb. I ran a 306 ages ago that was similar to yours Spoofty and ran a 780 vacuum. Likely over done but I ran a crazy rear gear as well (5.14) so it worked well. I did do a lot of tuning on the carb and was running way too much compression to the tune of having to use octane booster back in the 70's when gas was better than today.

 

I did see a gain from a 600 to a 780 by almost a tenth or so in the 1/8th mile.

 

Free is good though.. well usually. Just make sure the carb is in good shape as carb debugging is no fun.

 

-Stephen

[Pakrat 1,043]

I found this guide at Holley.com.

http://www.holley.com/applications/CarburetorSelector/CarbSelection.asp

 

Hey that is pretty cool, mine suggested a 570cfm so I guess I'm mildly over carbed but it runs great. I actually keep my choke disconnected but it had no apps for that so I had to list it as it should be with a manual.

[bnickel 10,004]

for mine it suggested a 650, a 750 and a 770. i was like make up your damn mind already. i'm running a 625 road demon and it works well. demon claims that their carbs actually flow better than what they are rated by about 10% or so. so that would make it around a 680.

[351carlo 10]

bnickel, my 625 wet flowed 743 :ohmy:

 

I love the demon carb.

 

I'd recommend the Road Demon 625 to anyone.

[bnickel 10,004]

wow that's a lot more than i was expecting it to be. yeah i love my demon carb too. i think when i get the cougar i'll use a 625 speed demon jr until i can afford to build the long rod, aluminum head, roller 351w and then i'll switch to a holley commander 950 pro jection unit with ignition control!!!:001_tt1: