Northstar build

[Parde_GT]

Hey, great forum you have here, seems to be much more direct than the other :doh: one.

I’m new and have been reading through some of the N* threads as I will be starting my own ’96 swap soon. It will be an ongoing project for a while but you have to start somewhere. I work in a machine shop so fabricating brackets and etc will be fine. I just haven’t done much engine building, quite a bit of repair though.

My goal is to get the N* to around 400hp with an 8K redline doing as much as I can myself.

At this point I am tossing around what to all do with the heads. As far as Chrfab cams what grind can one use and maintain a smooth idle – 280, 288 ? I also saw reference to only installing chrfab cams on the intake as there was not much gained over stock on the exhaust. If this is so then I take it you only have the intake sprockets redrilled?

As far as porting – is this something I could do myself? It doesn’t seem as though they need a lot. I say this as $2500 for chrfab to do it is beyond what I am willing to spend and I am not sure if anyone around here (Lincoln, NE) has had much experience with these heads.

I plan to use an alum flywheel and am pondering Eagle rods and Arias pistons. Rods run about $475, not sure about the pistons.

I would appreciate any feedback and suggestions. Thanks.

[crzyone]

Welcome to the forum.

Chrfab claims their mild 288 cams will make 75hp over stock with some head cleanup. With some porting, their springs and retainers I can see 400 crank hp with only those modifications, assuming you have an unrestrictive intake and exhaust. The idle quality should be good with the 288s.

Shaun here on the forum ports heads, ask him nicely and he might give you a quote. He has posted pictures in the past, looks like very good work.

For 400whp, I would get their more agressive cams. Fab up some shorty free flowing headers and it should be possible? Nobody on here has taken a N* that far yet.

[eHoward]

Welcome to the forum.

Will is doing a build similar to what you are describing. You might want to search through his posts or maybe he'll just answer your questions directly.

phpBB/viewtopic.php?t=602

About porting the heads, I'd be careful who I let port them. Make sure you get a shop that has experience and results with northstars.

[Parde_GT]

Thanks, I will check with Shaun and see if he would be willing.

I have read many of Will's posts both here and on Old Europe and have gained a lot of info so far. I hope to have more direct input from him as I go.

[whipped]

I believe Jon has the 288 cams, but I don't think he installed them... Those would be about as far as I would go for a "smooth" idle... That being said, I haven't heard any of the engines with cams myself.

Shaun did the heads for Jon, so he can fill you in more on that. I read the CHRF buildup, and they specifically mentioned turning the intake divider into a knife edge. Other than that, I can tell you that it's a lot of work. $2500 is a lot for the work, but it's a known quantity. Maybe you can find a local place to do it for $1000? You can get yourself into some trouble if you don't know what you're doing...

[whipped]

Oh! FYI!

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 8036261787

Gotta get the checkbook out, because it ends today.

[Aaron]

My God he really gained flow on the upper lifts. SHIT, over 50cfm, that's A LOT. I wish I had a N*, just cuz it'd be f-ing crazy with those heads and the cams to use them.

I mean seriously, he just matched STOCK 3.4 DOHC numbers! Ok ok, not to bash here...hehe...He did bypass the 3.4 on the exhaust, and matched us on the intake fromt he highest stock 3.4 flow numbers I've seen (They range from 270-280 on intake at .5)

[crzyone]

Damn, if I had a 99 or older N* I'd be all over those. Bolt on 100+ hp with no drawback is easily worth the money he is asking. Sweet.

I just want to add that those numbers are suspiciously close to the numbers chrfab has posted on their website. Seems like the numbers are changed to within a few cfm... I dunno, fishy.

[Aaron]

I just want to add that those numbers are suspiciously close to the numbers chrfab has posted on their website. Seems like the numbers are changed to within a few cfm... I dunno, fishy.

I noticed that too, but he seems to know what he is talking about..

[The Dark Side of Will]

He said that the heads were ported by Moroso (didn't think Moroso did anything "shop-like"), but never mentioned where all the other parts came from...

[The Dark Side of Will]

I’m new and have been reading through some of the N* threads as I will be starting my own ’96 swap soon. It will be an ongoing project for a while but you have to start somewhere. I work in a machine shop so fabricating brackets and etc will be fine. I just haven’t done much engine building, quite a bit of repair though.

How are you at wiring? What engine management and transmission will you be using?

My goal is to get the N* to around 400hp with an 8K redline doing as much as I can myself.

You need rods, pistons and springs to hit 8K reliably, but you already realized that.

At this point I am tossing around what to all do with the heads. As far as Chrfab cams what grind can one use and maintain a smooth idle – 280, 288 ? I also saw reference to only installing chrfab cams on the intake as there was not much gained over stock on the exhaust. If this is so then I take it you only have the intake sprockets redrilled?

What's your definition of smooth? The stock cams are as wild as it gets while still maintaining Cadillac idle quality. The 288's are pretty raucous and probably won't idle very well below about 1K RPM.

The issue with the N* cams is that they are regrinds... While you can attain more lift and duration, you can't mess with the variable that makes big cams streetable... high ramp rate. You're more or less stuck with the stock ramp rate, so the wizardry of streetable big cams that you see in LS1's is not available to the flat tappet Northstars.
The other thing that CHRF does is redrill the intake cam sprockets to advance the intake cams 8 degrees... this doesn't help idle quality either.

As far as porting – is this something I could do myself? It doesn’t seem as though they need a lot. I say this as $2500 for chrfab to do it is beyond what I am willing to spend and I am not sure if anyone around here (Lincoln, NE) has had much experience with these heads.

CHRF has the benefit of experience and experiments behind them. Basically, that he does on the intakes is smooth out, clean up and knife edge the cylinder divider, profile the valve guide, etc. He does more on the exhaust. The stock exhaust port is oval. He smooths the walls and floor and hogs the port roof out to the stock exhaust mani gasket, which is round, so it ends up being a D shaped exhaust port. Try it if you want, but when the time comes, I'm going to spend the money to have AJ do it...

I plan to use an alum flywheel and am pondering Eagle rods and Arias pistons. Rods run about $475, not sure about the pistons.

I would appreciate any feedback and suggestions. Thanks.

Eagle rods are what I have. They're great for the money. I'm going with CP pistons, though. CHRF's pistons are designed for high boosting high RPM sand rails and are thus heavier than they need to be for high RPM N/A use.
SPEC flywheel or CHRF?

[whipped]

Damn, if I had a 99 or older N* I'd be all over those. Bolt on 100+ hp with no drawback is easily worth the money he is asking. Sweet.

come to the dark side... you have 5 hours to decide. :la:

Actually those heads are for a 93-94. Using them in anything else would require silicone to seal the mouse hole EGR ports in each intake port.

[crzyone]

The issue with the N* cams is that they are regrinds... While you can attain more lift and duration, you can't mess with the variable that makes big cams streetable... high ramp rate. You're more or less stuck with the stock ramp rate, so the wizardry of streetable big cams that you see in LS1's is not available to the flat tappet Northstars.

Am I right to assume this isn't an issue with 2000+ N*s with roller cams? Would be cool to have big cams and streetability like an LS1.

[crzyone]

come to the dark side... you have 5 hours to decide. :la:

I'm way to far along to switch now, not to mention over $10 into this swap so far. Not sure if its going to be worth it in the end to say I have the first 2000+ N* in a fiero.... Not much benefit.

[The Dark Side of Will]

I was designing billet 8620 roller blanks for Alan, but somebody else beat me to it. Haven't checked to see if they're on the website yet, but he told me over the phone that he has a source for billet blanks, which would bring the roller cam Northstars up to the same level of cam tunability that LS1's and other roller cam engines have.

However, with the Y2K+ FWD engines you run afoul of the horrible intake/exhaust flow ratio when you try to tune for N/A power.

You could get the RWD heads, which have vastly improved exhaust ports over the FWD Y2K+ heads, but the coolant connections on those heads are at the front of the engine... That could make for an interesting way to use an electric waterpump... there would be twice as much cross-compartment plumbing, but you could connect the lower radiator hose on the right side of the car to the back of the block using CHRF adapter plates, then connect the left coolant pipe to the front of the heads using custom adapter plates. Plumb an electric waterpump in place and provide for heater core circulation and oil/water heat exchange and you'd have an nice cooling setup.

[crzyone]

Instead of going through the effort of replacing the entire heads I think a good port and polish could compliment the cams. In reality, how much power do I really need. 400-450hp would be insane in a fiero and doesn't sound like it would be all that difficult to achieve.

In the end I think it would be cheaper to get that output from a N* going NA instead of turbo.

[The Dark Side of Will]

Yes, I think it would. I'm hoping that buy the time I get done with this engine, I'll be able to squeeze 460 rwhp out of it (100 rwhp per litre). Of course it'll be an unruly sonofabitch that pegs the limiter when you breath on the pedal, but isn't that the whole point?

[crzyone]

That sounds just about right. I want 400whp, that should still be fairly streetable. 400hp and 20+ mpg would be my ultimate fiero.

[whipped]

I was designing billet 8620 roller blanks for Alan, but somebody else beat me to it. Haven't checked to see if they're on the website yet, but he told me over the phone that he has a source for billet blanks, which would bring the roller cam Northstars up to the same level of cam tunability that LS1's and other roller cam engines have.

Does that mean anything good for those of us without rollers?

[crzyone]

I was designing billet 8620 roller blanks for Alan, but somebody else beat me to it. Haven't checked to see if they're on the website yet, but he told me over the phone that he has a source for billet blanks, which would bring the roller cam Northstars up to the same level of cam tunability that LS1's and other roller cam engines have.

Does that mean anything good for those of us without rollers?

Come to the darkside, we have better cam options