[Chevyguy305r]

just wondering what kind of power i would gain if i added an rv cam, headers and an performer intake manifold to my 1984 gmc 1/2 4x4 305. right now it has ported stock heads, dual exaust and a k&n

[dallam1]

I think that would be a worth while endeavor. Just keep those header tubes on the small side and the exhaust pipes on the order of 2 1/2" and you'll definetely reap the fruits of porting those heads!!

[Chevyguy305r]

i am hopping for around 190hp and maybe 320.lbs, is this possible with this combo

[dallam1]

When I had money, I had a nice little 20 foot boat with a honey of a 305 Chevy in it. That sucker would run about 45 miles an hour. "Mercury Marine" rated the engine at 195 horse power and that was with stock heads and cam. So, I believe you are underrating that motor with those mods.

[Ohio-Dan]

Try this link for a 305 build and dyno tests. Dan

http://www.goingfaster.com/spo/carcraft325hp305.html

[reddwarf]

[quote]Originally posted by Chevyguy305r:
<strong>i am hopping for around 190hp and maybe 320.lbs, is this possible with this combo</strong><hr></blockquote>

You'll have to hopp for a long time to get 190 HP.

The SBC weighs a lot more than 320 lbs too

JK

Your 305 should respond well to those mods, but I think you will lose a little bit of bottom end. If you can juuuuust turn over your tires now, you probably won't be able to after the mods....Also, from the article above, it looks like you're not going to see 320 ft-lbs out of it


DO you wheel your 4x4 at all? If so, what kind of wheeling do you do?

[ March 05, 2003: Message edited by: reddwarf ]</p>

[Chevyguy305r]

I actuall have no probs doing burns out. i have a friend who has an 1985 chevy 1/2 305 auto that can lite them up at will. of course we both have 3.73's.

[F-1Rodder]

dallam1: your 305 boat motor would not be built like a car/truck motor. If you have ever listened to a boat idle, they have a loping idle. The cams are power cams because nobody in a boat expects to get good mileage but wants performance. So I believe what you say, but doubt that the stock cam in chevyguy305r's car is as powerful as your boat motor.

[Chevyguy305r]

Well the cam in my truck 305 is pretty lame, hell i even consider the cam in the lb9 230hp 305s, pretty mild. will since it is a truck i am looking for good power from idle to maybe 4500-4800 rpms. i want torque to hopefully stay below 2800rpms

[nicefrog]

Any cam around 250 duration and .43 or .44 lift maybe even less lift is ok, will get you near 300 hp (about 290?) and keep your peak tourqe at around 3000-3500 rpm, comp cams xe250h or something similar is what to look for, something a bit smaller if you really need that torque to peak before 2800 rpm, but the difference at 2800 is only a few foot lbs with that above cam (343 lbs@ 3500 but still 334lbs at 2000 rpm). Try and match the header length to the tourqe range you want, there are calculators on the net to work that out. Also put a crossover pipe the same length back from the end of the headers as the end of the headers are from the valve if that makes sense : ). I wouldn't worry about the inlet manifold, that's a waste of a big lot of money for a couple of hp. Just do some work on the stock 4 barrel manifold. David Vizards intake book (how to build hp 2) tells it all, cheap book too. With your ported heads, some good tuned headers will add you 50 hp no problems

[dallam1]

Getting back to the boat thing. If I'm lying I'm dying. There was a small micro switch positioned at the "idle position" of the throttle on the Q-Jet. When you would bring the throttle back to idle, the micro switch would null out 4 cylinders! The result was that it loped a bit but idled slow. This was done on purpose to help "ease" the transmission in and out of gear. For quite awhile I thought the engine wasen't ideling right and messed and messed with the mixture and timing and then finally gave up and took it to a boat shop. You guessed it, they had quite a laugh when I told them how the engine was ideling! Incidently, that goes back to the days when my wife looked like Susan Anton in a bathing suite. Now she looks like Phyllis Diller!

[Turbostan231]

You better hope your wife doesn't frequent this site...

[dallam1]

Are you kidding! Misses Dallam1 better not be on the internet. That big rear of her's better be in the kitchen making me some grub while I enjoy a cold one and surf the net! It dosen't get a whole lot better than this!