Cam selection question

August · Posted: Mon Aug 25, 2003 3:29 pm Post subject: Cam selection question

Hello,
On my 87 El Camino SS, it has a 305 with the below mods. I have an Edelbrock performer plus cam #3702 specs are
Specifications:
* Advertised duration: 244 intake/264 exhaust
* Duration at .050 in.: 194 intake/214 exhaust
* Gross valve lift: 398 in. intake/442 in. exhaust
* Lobe separation: 112 degrees
* RPM range: Idle to 5,500
* Designed for optimum torque from low end to the mid range.
* Smooth idle for daily driven vehicles.
I also have a Edelbrock Performer #3706 Intake manifold, I bought these as a set as Edelbrock claimed it would put out in excess of 200hp(it the wekest feeling 200hp I've ever felt), I also have Thorley tri-Y headers, custom exhaust, flowmaster, and Carter street/strip fuel pump. Heads are stock, air intake is a dual intake, ZZ4 prom all else is stock. This still does not put out the HP I want, what other cam should I try? I need to keep this smog legal as I'm in CA, I would like it to have smooth idle but from there power should be there when I need it. I don't like getting beaten by wanna be rice rockets and out here there are alot of them! Also would head work help and if so what should I get done? I'm not looking to go 150mph but I would like decent gas milage when my foot's not in it but still be able to kick some butt when the need arises. Thanks for any and all help.

August

theelcaminofactory · Posted: Tue Aug 26, 2003 4:44 am Post subject:

Sorry to say but 200 hp is weak, with the addition of the cam and the headers alone you should be creating close to 200. Sure everything is in tune? Sounds like possibly you have a fuel or electronic problem. And long as your inquiring about what you can do with the heads...here's my advice don't rebuild them, toss them out and get the Edelbrock Performer Heads (not Perfomer Plus) or something similar. What kind of exhaust are you running, true duals or a cat back? If it's a cat back dual system, is that the original converter (could be partially plugged up)? If you breath in a big amount of air/fuel, you gotta be able to exhaust it also. Those stock heads you have could (probably) be choking that 305. Remember the old saying about trying to suck a golf ball through a garden hose? 305 isn't a lot of cubic inches, but you should be able to pull close to 1 hp per cubic inch, even with those low compression pistons. My recommendation is to get rid of those heads with their small valves and ports, and also upgrade your distributor and wires for a higher spark, and check out the converter if it's the original. Hope this helps. I realize those aluminum heads aren't cheap, but you got to kinda make all your mods work in conjuction with or compliment each other.
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August · Posted: Tue Aug 26, 2003 7:47 am Post subject:

I kinda thought the same thing on the fueldelivery side, yesterday I ordered the Carter fuel pump should be in my car by this weekend, I don't know how much this will help but I'm sure it can't hurt. On the Performer heads, are they smog legal? What type of Distributer should I be running? I run 8.0mm wires should I get bigger ones? I have kind of a stupid question, what do you mean by catback system? Mine is custom, starting from the headers it goes into a 3" high flow cat from there it goes to a flowmaster exhaust and then goes out the back to a single, this is not a dual system, the reason for this is the shop that did the exhaust reccomended a single as they said they could create more HP that way than a dual. The sound is exactly what I wanted, it looks stock but when you punch it the sound is there and at freeway speeds I can still hold a conversation without yelling to my passenger Smile

.

August · Posted: Tue Aug 26, 2003 8:49 am Post subject:

Also,
I forgot to ask, you mention top check the converter, what would be the symptoms of a converter going bad and how could I check it? Thanks for the help!

ElkyPete · Posted: Tue Aug 26, 2003 8:57 am Post subject:

Did you play with the Cam settings to optimize the timing?

You can squeeze up to 400 Hp from your 305 but not with factory heads. If you plan on upgrading to a 350 or 400 block in the future then go with the Edelbrock heads or AFR 195C or better heads. Otherwise, use the Vortec heads, Pace performance parts sell them drilled and tapped for non-Vortec intakes.

If you go with aftermarket heads, Edelbrock or AFRs get the smaller chambers, just a preference but they keep the compression up. If you go with a 72cc head you'll loose the little bit of compression that you have now. so 62 / 64cc heads will be better for your 305. You could even shave the Vortec heads a little to increase the compression on that 305.

A Comp XE268 Cam kit is a good all around mild Cam good for 1800 to 6500 RPM or somewhere close to that. That, the heads and intake should give up about 350 maybe even more streetable Hp with your headers.

Get a good timing chain and gearset that is adjustable.
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1972 El Camino Custom 400
1976 El Camino Classic
1980 El Camino Super Sport
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August · Posted: Tue Aug 26, 2003 10:53 am Post subject:

ElkyPete,
Are the Vortec heads a direct bolt on? Also, are they smog legal? I have a double roller timing chain already installed, I've been flip flopping on the engine swap, I know it's an easy swap but the smog police are a pain in the butt here. The last time I had to get smogged, It took calling Edelbrock and the CARB in Sacremento just for the intake manifold, and that was a direct replacement for the stock manifold! Will my intake fit those heads or should I call Pace to find out? Thanks for the help as always.

ElkyPete · Posted: Tue Aug 26, 2003 12:30 pm Post subject:

GMs Vortec head are offered on normal production engines. A 350 with the same heads is very good.

If you get the one that is tapped for non-vortec intake yes it will fit. It will also fit a 350 with the same set up. Here is the deal. If you don't have the cash right now to upgrade the block, then you can get the things like heads and Intake and carb, to a lesser degree, things like that that will also add to a good strong 350 block or even a 383. So they help in the immediate time and will still give you a good value for upgrading when you get the time or cash.

You can do things with the 305 to add ummph. Those same steps with a 350 will add more Ummph. So if it is all done right your adding to the 305 but building up to the 350 swap. And with a 350 it will be street legal if the 305 is. Its just more displacement. Heads, intake, carb and exhaust are all the Smog cops are going to care about. They will not know if it is a 350 or a 305, if you go with a new generation 350 block the dipstick is on the same side as the 305 so no obvious evidence. You could have an issue with the Fuel Pump on a new SBC block. I don't think that they are drilled for mechanical fuel pump.

But Small Block Chevrolet is a Small block Chevrolet from the outside they pretty much look alike. Sure some can tell by looking but the (aftermarket parts) are almost all interchangeable from one to another so with the goal of the larger displacement block you can buy to that and bolt on to the 305 you have until you get the upgrade.

Just my thoughts on the matter.
_________________
Home Site: http://www.elcaminoplace.com
1972 El Camino Custom 400
1976 El Camino Classic
1980 El Camino Super Sport
E-Mail: engstrvr@sbcglobal.net

SirVette · Wrench Necoa #: 1507 Joined: Sep 16, 2003 Posts: 17

elcaminopower400 · Wrench Necoa #: 1521 Joined: Sep 19, 2003 Posts: 43

300 t0 400 hp is a tall order for a 305 engine...The amount of money you spend on parts alone for that will be the same as buying a bigger block engine..i have yet to see a 305 run at 400 hp levels without major expensive mods..if you want to get more bang for the buck you should move up to a 350 or higher..a 305 just isnt going to get it..Im not knocking 305s..but its just not a practical way to go. If you are stuck on the 305 go for the vortec heads..i have heard great things about them..Make sure you get them ported and polished and matched to your edelbrock manifold..msd box wouldnt hurt either..If your engine is fuel injected you will have to use a different cam that can accomidate a mechanical fuel pump..the stock cam is made for fuel injections only. ( I made that discovery by experience lol). In the quest to gain horse power you cant help but to loose some mpg..but thats just a trade off..running a higher compression ratio might help some as well. But after all being said..you should just check to see if what you have is tuned right..

August · Posted: Tue Oct 14, 2003 8:57 am Post subject:

elcaminopower400,
Thanks for the info, I agree with you 400hp is a tall order for a 305, The stuff I was getting for my 305 I made sure it would bolt onto a 350 when I go that route(and I will) but for the time bieng I wanted to get this engine running as best as it could. In my Tranny post you will see that I had some serious problems and and leaning heavily toward that bieng the problem as to my HP loss. On the Vortec heads, I too have heard good things but I don't know if they will be able to monut onto my 305 and then do the switch to the 350 later on, my 305 has the bolt pattern thats offset in the center I don't know if the 350's are that way or not do you? Thanks again for all help and info.

August