86 Replacement Intake Manifold options

**robertwilbanks** · 05-30-04, 11:48 AM

The previous owner of my 86 broke the bolt on the intake manifold at the thermostat housing. Instead of repairing it he drilled another hole next to it and put a sheet metal screw in with apoxy. I am going to replace the intake manifold and want some input about the difference between the Edlebock and the Accel or any other options. They seem to be compariable price wise but if I am going to spend the money I want the best performance.
Thanks

**Edmond** · 05-30-04, 05:55 PM

Unless you're also going to do cam and head work, changing the stock intake manifold to a high performance one will just be a waste of money.

Are you going to do the heads and cam too?

**robertwilbanks** · 05-30-04, 06:39 PM

no, just replace the intake manifold

**Mart** · 05-30-04, 06:43 PM

I'm not sure I buy that one Edmond, the biggest downside to the L98 was the intake, after all it was pretty much the same one they used on the 305 TA, Z28,

I can tell you that I just finished redoing my intake (which included fixxing 2 broken thermo bolts) while I had the intake out I ported and polished it, as well as gasket matching the heads to the intake. Kept the stock runners and ported the plenum.

Now I have this new car, that boasts a noticeable heap of HP, have not dynoed but I'm thinking maybe 20-30 hp gain, according to my G-Tech.

Just my .02 worth

Mart

**Edmond** · 05-30-04, 10:02 PM

Ah, but that's a comparison to a ported intake manifold, which pretty much throws the comparison off. For that matter, he could have his stock intake manifold ported as well. Of course, the bolt is broken in the manifold so that won't happen.

**Mart** · 05-30-04, 11:07 PM

What you think that can't be fixed,

And I took this mess to a speed shop and they screwed it really bad, then I found a guy who welds aluminum, and wow did he do an incredible job.

Anything can be fixed, and besides ever price a new manifold. IMHO it's cheaper to fix and port your stock one. It cost me 70 for the repair and I ported it myself, take your time, read up on it and the chances are it might be better than some of the shops that do porting.

The goofs that tried to fix mine actually broke a 3/8 drill off inside, then when I went to pick it up, and they had'nt fixed it I took it to the welder and he found a the piece inside, I will never trust Agostino Racing Engines again. Ooops did I say that.

Mart

**rrubel** · 05-30-04, 11:16 PM

I'm in the process of installing the Accel SuperRam plenum/runners/manifold (along with all the other "hey... if you're doing THAT, you gotta do THIS" stuff). My biggest impression of the manifold is that it's cheap-looking. It's smaller on the sides than the stock one, so the edges of the gaskets show. It's rougher on top. The instructions suck. It's supposed to make tons of power, but only in the right combination.

The way I see it, you've got the following options:

1. Stock manifold. Cheap, cheap, cheap. Under $100 on eBay. Port it, add some bigger runners, and you've got a mild, simple, inexpensive power boost.

2. Accel SuperRam. Not really any good by itself, and expensive. Worth getting if you plan to do the rest of the conversion later, but don't pay full price for it.

3. Edelbrock, etc. Don't know a lot about them, unfortunately. They've been around a while, though, and people like them.

4. Stealth Ram or LT1 intake. The first is a bit pricey, the second is much cheaper but needs some prep work to accept a distributor. Either will greatly improve the rev range and power of your car. They are essentially a one-piece plenum/runner/manifold setup so you'd do away with the rest of the TPI runners/plenum as well.

If I were doing all this again, I'd probably go with the LT1 intake. Less parts, looks to be less hassle.

Of the options you mentioned, none will give you lots of extra power without doing other stuff as well...

Hope I haven't confused you more...
[RICHR]

**Edmond** · 05-31-04, 09:46 AM

Originally Posted by Mart

IMHO it's cheaper to fix and port your stock one. It cost me 70 for the repair and I ported it myself, take your time, read up on it and the chances are it might be better than some of the shops that do porting.

That's my main debate this winter: do I port the stock one or go with the TPIS "Big Mouth"? TPIS claims that the Big Mouth will outflow even a fully ported stock manifold. Of course, that's their product so what else woud they say?

**robertwilbanks** · 06-01-04, 12:06 PM

Well, it was going to be $225.00 plus tax and shipping to get a used stock manifold so I ordered the Edelbrock from Summit for $390.00 including shipping. I will follow up with my impression of it when I get it intalled. Thanks for the help.

**robertwilbanks** · 06-08-04, 05:19 PM

Got the manifold installed this weekend. The important thing I discovered is that the car will not start until you plug ALL the wires back into the distributer. I took digital pictures before I took it apart but missed seeing one connector. It was easier than I thought it would be to replace the manifold plus I spent enough time to bond with my vette. Performance wise I cannot tell and difference with the Edelbrock since I only drove it a half dozen times prior to the replacement. Thanks for the input from everyone.