I don't really want to do the save and wait thing because I'm really waiting to just build a 454 motown and don't want to dump a ton of money in to the stock engine. If I were to do the save and wait game I'd definitely go with vortecs because of everything I've heard about them being excellent performers. However, like I said, I don't want to dump a ton of money in to this engine as I am going to go with a motown 454 with TBI flex-jection (www.rochesterproducts.com).

What I want is just some more grunt for autocross since I'm already going to be in SM2. I'm finding that I'm in 2nd gear for 95% of the course and could use more midrange power on the long straight aways. I'd rather put more money in to suspension and tires, right now, than the engine.

 

How competitive are you in SM2 right now? I doubt 30 hp will make a huge difference. Are you within half a second off TTOD for class?

 

I think you'll get just as much, if not more, power out of a set of headers.

 

Already got those. I've got a summit 1103 cam, ~8.5:1 CR (engine was rebuilt just over a year and a half ago with hypereutetic pistons), headers, sidepipes, procomp 50k volt HEI, and an edelbrock 1904 q-jet rebuilt by lars.

From what I can tell BSP, BS, and SM2 are my 3 class choices and I think I'd have the best chance in SM2 as I'd have no chance in BS or BSP against RX-8s.

Hence I've come to wanting a cheap set of heads to give me some decent power to get the midrange grunt since I've got a 3 speed and don't have the ability to switch between 2 mid gears to get the power going.

Edit: For suspension I'm going to go with the front transverse leaf spring kit from either vansteel or VB&P, a composite rear spring, and bilsteins all around. Step by step, though.

 

I autocrossed the 78 w/ a 700R4, but I was "blessed" w/ 3.55:1 gears.

I personally would put the money into suspension or tires. You'll get the best gains out of tires, promise. What are you running right now?

 

That's next but the next autocross isn't until October 7th and I won't be able to get a new set of wheels and tires on before then, but I CAN get a set of heads on before then, if I can get the right price.

I do agree that I could get more seconds off with better rims + tires, but like I said, not gonna happen before the next event. stock 15" rims with Cooper Cobra GT 255-60-15s They suck but are getting pretty worn down so they're doing alright now.

I've got the alignment set right and new gas charged shocks front and back. (KYB gas-a-just in front and gabriel ultras in the back) Front suspension has been rebuilt with polyurethane bushings a month ago or so. The car handles decently well for its age, it just needs more modern technology added to it and more power.

Oh and I'm blessed/cursed with 3.07 rear gears. Blessing for the highway, curse for race.

 

For autocross purposes, the front suspension really isn't too bad. The rear suspension sucks and will stab you in the back eventually.

I may start autocrossing the 78 again after I build a new motor for it, but to get serious I'd have to throw a good set of rims and tires on it. Pace car wheels and firehawk indy 500s (also 255-60-15) do not cut it.

I autocross my 02 exclusively now, and that car is so technical it's not even funny. (A little extra gas = understeer a lot of extra gas = oversteer, back off the gas and all is well. Love it.)

 

Down the road I figure I'll eventually correct that rear suspension issue with a C4 rear end. Not too difficult of a fix and with the leaf springs in front and back it should do quite well.

Funny you mention the way your C5 behaves around corners, my '81 behaves EXACTLY the same way.

 

I *thought* my 78 handled that way until I started racing the 02. There's just a lot more finickiness at the limit in the 78. I can't tell you the number of times the car just up and broke away from me without warning. The 02 only did that once, when I was going gungho on a morning lap... third person out and found a big patch of gravel.

 

With the stock alignment settings, my '81 did that all the freaking time to me. After getting it set to VB&P's recommendations I feel totally in control of it all the time now. Amazing what a correct alignment does for handling.

 

Still need some casting numbers. I asked some of my car buddies about the camelback heads and it's my understanding that those are good for the high RPMs of like over 4000. They've got decent 64cc chambers and big valves but I need more midrange power to get my power to come in sooner or just more across the board. So the L98 heads are sounding like the key.

 

I realize I leave some hp on the table but I don't believe I lose any torque to the more expensive heads. My L98's and 650 speed demon give me good low end torque and instant throttle response plus the reduction of weight on the front end of 50-60 lbs. I have never autocrossed, but seems to me the top end hp number everyone brags about from their high flowing al heads would seldom be reached?

 

If you're racing stoplight to stoplight in a school zone, yes, the L98 heads will suffice.

For all-out power, it's just money wasted. Now if you can find a good deal on a used set of L98 heads and don't mind doing the same job twice, that's one thing. Fact of the matter is, for most of us, power is a drug. I spent $2000 or so to half-*** my engine together by doing H&C, putting AFR 195s and a 216/216 cam on a block that is now making at most, about 8:1 compression. If I'd done it right and gone with a new bottom end (about $1500 at the time (or just do a ghetto rebuild and swap pistons for $400)) I could do the job once and have around 280 or so at the wheels, which would not be bad at all. As of now, I'm putting out 241 at the wheels and while the car is fun, I'd really like it to have more.

I think I'm going to go crazy and do a full engine, new block, new heads, "ze works", all the way I want it, the first time.

But the bottom line is that there is absolutely nothing wrong with what you're doing if that's what you TRULY want to do. I just don't want someone to get something they think is more than what it is - so many people seem to go for cheap horsepower these days and that is what they get - cheap. Not as much money as if you'd planned and built a motor as a package in one go.

Anyways - Kalway, one thing about the camel hump heads is that they generally are not drilled and tapped for accessories from the factory, and on top of that, they are iron heads. You might want to actually consider going with a set of L98 heads, you could probably salvage them for very cheap.

-Steve

 

Pretty much. You're lucky to make it over 65 at autocross. It depends what club is holding the event, though. They all make different track designs. One of the clubs is a corvette club and they have a lot of point and shoot type tracks where the high torque and hp cars can do extremely well. Some other ones have long sweeping turns modeled after road courses, and others have ultra tight twisty tracks where your ultra horsepower only helps push your rear end around the twisties.

Right now I'm needing a better power:weight ratio so I can keep up with those little miatas and S2000s that I'll be up against in SM2.

 

Isn't that what I said in my bump post? Getting the camel hump heads drilled for the accessories wouldn't be a huge deal as my engine builder would be the one getting them for me anyways. The shop I had rebuild my engine has been in business since either the 60's or 70's (Motor Machine in National City) and they have VERY good prices and do an outstanding job, from what I can tell. Even my grandfather apparently used them when he used to live out here.

So I do want to find a set of L98 heads but I need to know some casting numbers so I can call around and see if I can find them. Junk yards won't know what the heck an L98 is so I'll have to tell them a casting number.

250 - 270rwhp would be perfect to me. The whole bottom end of the engine is new, with the exception of the block so it's pretty much ready for it.

 

Get the L98s ... they'll do all you're asking for & more ... for small $. L98 heads are what comes on both GMPP ZZ4 and it's circle track cousin x603. And don't take too seriously the low hp rap those L98 heads get ... PLENTY of nascar touring series "supertrucks" have "sealed" x603 in a 3200lb tube truck chassis, QC rear etc ... and they're very competitive with the "built" motors ... see em at tracks at HickoryNC, Caraway NC, Myrtle SC etc.
*edit ...and NO, supertruck are not allowed to port their L98 heads ... they're DQ if it even looks like they've been touched. So, they're doing it with stock L98 ports.

 

Sorry if I had asked this before
Can someone identify the 3947041 head? Valve size, chamber CC ect:
My Corvete is in the shop and the top end is all torn apart.

I need to get it back together asap

I also need a way to tell if the heads have been milled ...is this possible? Does anybody have standard dimensions i can go by?
I was also told that the heads were modified on the top to accept the screw in studs....... It's obvious I have no experience as far as engine building goes
Thanks
Bob

ps: Sorry Jackson
I am having a problem which is causing my memory to get cloudy

 

I'm convinced on the L98s but how about some casting numbers I can look up? Are there any besides 113?

 

3947041....69-70...302/350......"Right angle" casting identifier, 64cc chamber, accessory holes, good HP head

www.mortec.com and press ctrl F to use the search function on IE that's how I've been doing it.

 

Thanks Kal
I was told they were straight plugs

I guess Ill have to look at them again.

Thank you
Bob