SSI size

[rgoodrich]

I am about to rebuild my 3.2 due to bad valve guides. Due to 150k miles, we will do a complete rebuild. Plans include race ware studs and rod bolts, 98mm P&C and cams yet to be determined. I would like to go with SSI headers. I am afraid that to O.D. Will be too small for 3.4,
Anybody have words of wisdom?

[Steve W]

Yes, they are too small. Either go with a properly size header, or if not stick with the factory stock exhaust. On many 3.4s I've seen, even with all the tricks in the book in the motor, SSIs will limit the rwhp on a Dynojet to no more than 220, whereas the stock exhaust will allow output to 230-235. That should tell you something.

[rgoodrich]

Steve,
I appreciate your response. I am starting to look at exhaust options:headers of course, but I need excellent heat. I will need to do some research.
Still in the planning stages,
I would be interested in your opinion in relation to 3.4 chipped with headers vs those with stock exhaust. Of course, there are many variables. I just thought you might have a general idea.
Robert

[Steve W]

Headers with some type of muffler are anywhere from 0 to 7 hp more than the stock heat exchangers. If you need heat, the stock heat exchangers are hard to beat. In fact the stock muffler and combined with a euro premuffler or sport cat, is actually not as bad as some would lead you to think. Other options are Fabspeed, B&B, and 993 heat exchangers that can bring challenges of either fabrication, or being loud for street use, depending on your definition and tolerance of loud.

[rgoodrich]

I have a cat bypass with an otherwise stock exhaust , for 7 hp, I'll keep the quiet. No use attracting unwanted attention!
I had a full Fabspeed headers and 2in 2 out, in my SC,
but the droning was so bad, I had to get rid of the system.

I want to put one of your chips in my car. It needs a top end, so I'm a little reluctant to push it.
What do you think ?
Robert

[Steve W]

I'm assuming you're talking about chipping the car prior to rebuilding the motor, as top end issue would be a mute point at that stage.

A 3.2 that needs a top end is typically just a worn exhaust valve guide problem that causes oil to seep past the guides and consume oil faster than spec and sometimes additional puffs of smoke from burning oil. That is really more of an annoyance than of any additional stress to the motor. Chipping the car for better response and performance has no relevance to the valve guide wear or lack of, and doesn't accelerate any additional wear or cause any additional stress to top end any different than running the car as it would normally. So no worries if you'd like to chip your car now as it is, and enjoy and realize the true performance and fuel efficiency your motor can deliver.

[rgoodrich]

Thanks for the input. I'll be talking to you soon!

[TT911]

Robert, if you're referring to the need of heat exchangers check out Hayward and Scott, they do sports headers in sizes of 1 3/4" ( 45mm ) Od 16swg tube with a ID size of 15/8 " (41mm ) . And then wrap a heat exchanger around afterwards. I'm looking in to this my self as even a standard 3,2 engine is restricted with SSI's

Let me know if need anything else,
Cheers, Thomas

[Lyle O]

Brian over at M&K can do a beautiful set of headers with heat exchangers wrapped around them. They aren't on his web site, but he can do them. Not cheap, but you get what you pay for. His stuff is top notch.