quote Originally posted by PBJ: We have run est 340 crank hp on a stock 4.9 bottem end with 180 000 + k on it, using regular engine oil. And no problem at all with the engine mechanically, just trannies. So I cant say how much it will take. As far as psi you can only go so high until you have to remove so much ignition timing advance that you are not creating any more power. approx 5psi stock form and 8 psi with the work I have done to our 4.9. Pete

OK thankies, Just trying to decide if it would work to helping the upper end a bit, give the motor more legs so to speak.

remember the rods on a Nstar are powdered metal and only good to 7000 rpm after that they will break for high rpm use the crower rods

I did not know this. So are the later N* rods better for high RPM use? Will they work with the '95 crank / pistons?

hmm. I best stay at 6500 then and just get the thing going with 5psi.

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Bill Strong
Racing Strong Motorsports

[This message has been edited by Bill Strong (edited 01-28-2005).]

quote Originally posted by PBJ: We have run est 340 crank hp on a stock 4.9 bottem end with 180 000 + k on it, using regular engine oil. And no problem at all with the engine mechanically, just trannies. So I cant say how much it will take. As far as psi you can only go so high until you have to remove so much ignition timing advance that you are not creating any more power. approx 5psi stock form and 8 psi with the work I have done to our 4.9. Pete

Thank you. As far as timing, Im going Carb'd with a Hyfire box so I will be able to get add on boxes for boost. Maybe time to start looking for that 650 CFM Holly 2 barrel

Bill
You were asking about the valve springs. Here are some measurements from the CHRFAB springs

Free height 1.675"
O.D. 1.131"
I.D. .833"
Wire Dia. .146"
coil bind .753"
105lbs. @ installed height 1.19"

[This message has been edited by spearce (edited 01-30-2005).]

Bill Strong
the new version of the engine has forged rods in 2005 in the rear wheel drive northstar all others are PMR

quote Originally posted by spearce: Free height 1.675" O.D. 1.131" I.D. .833" Wire Dia. .146" coil bind .753" 105lbs. @ installed height 1.19"

Yours are ~216lb/in springrate

Could also be 3.4dohc springs..... I don't have all the specs on them, but
Free Length 1.6551
Load (Closed) 65 lb @ 1.400
Load (Open) 160 lb @ 1.030

That leaves you with a 250lb/in springrate, or ~ 116lbs @1.19" height
anyone know the dia's and/or coil bind height? They're a little stiffer though.....

I brought the heads home from the shop. I'll go down to the junk yard this week and have a look to see what is close in size

The 275 HP engines redline at 6400. The 300 HP engines redline at 6700. Absolutely do NOT exceed these limits with stock springs. You WILL crack a lifter and ruin at least a cylinder head.

The lifters do not start life as one piece of metal. They are steel but have a cast friction surface friction welded to the top. Over-revving the engine will run them into a no-follow condition and the resulting impact loading will crack the friction weld and the lifter will come apart. It will ruin its own bore and thus that entire head.

The stock rods are quite strong. The weak point is the torque-to-yield rod bolts. These will not take a whole lot of time above 7,000.

any idea of what head studs to use? I remember reading somewhere something about VW studs... don't know which ones though.

Bill

Yes, I will like to hear more about the availability of Studs for the heads Vs the Stock head bolts.

I heard that the N-star blocks have a weak coil thread [on the block], and a new coil fix are needed almost every time, NOT GOOD!

I really want an option for this problem...

Thanks
James.

You are supposed to TimeSert the block. I have this kit, which is rather pricey. Once the serts are in you can reuse them a few times.

Time serts are supposed to be indefinitely reuseable. They're just like having steel threads in the block. They're cheap, too, only about $4 each. The kicker is that the tool set to install them is about $300 and it takes upwards of 12 hours of work to install all 20.

Don't get all wrapped around the axle about head studs. Stock bolts are plenty strong for N/A use.

That said, the Northstar can use VW head studs. ARP P/N 204-4204. They are ~$100/set from Summit. You'll obviously need two sets, one for each bank.

From www.mantapart.com the stock ho springs for a 2.3 quad 4 not a 2.4 twin cam. I would bet that the springs on the 3.4 tdc are a better bet. I think bryson and his dad were looking at using 3.4 tdc springs in his project, Ill have to go find that thread.

OP 1567 H.D. High Output Valve Springs: Upgrade or restore your engine to the factory HO spec valve springs. Can be used with up to .410" lift cams. Spring rate of 75-80 lbs installed @ 1.437" and 205 lbs @1.043".

OP 1567 Set of 16 $100.00

OP 1519 H.D. NHRA Legal Racing Valve Springs: Conical factory-type single spring that will accomodate up to .440" lift and give a firmer rate for high performance useage. Spring rate of 85 lbs. installed @ 1.437" and 235 lbs. @ 1.000" open.

OP 1519 Set of 16 $275.00

That's not even close...

Thanks Will. I was thinking the same thing. I was reading the MDS on Nylon66 last night. This will save me a few bucks. and keep my wife off my back. she was not happyu about me looking for another manifold

quote Originally posted by Will: Nylon manifolds are QUITE strong. The Northstar was the first major application that used a composite manifold, so GM was a little wary of the way it might behave; hence they included the sneeze valve. LS1 manifolds do not have a sneeze valve and are tested at 80 psi. Nylon 66 is not known as a fragile material. If you're THAT worried about it, add a stronger spring behind the sneeze valve. You just need to keep it closed at your max boost level.

Well, it's not a fragile material unless it's a 3800 series 2 n/a intake... the EGR port cooling passages were too small and dexcool combined with heat and air breaks it down. GM has a revised manifold to address the issue on that particular engine. The aftermarket Dorman intake seems to have another issue with the material around one of the bolt holes having issues with collapsing while torquing down the intake.

Sorry about hijack... back to the cool stuff :-)

I've heard about the 3800 intakes having issues.
The exhaust temps with EGR is why the Northstar EGR is routed through the coolant manifold to cool it down before being introduced to the intake.

Pretty much every turbo LS1 in existence is running a plastic manifold...

Cool then. so I only need rings now. I have one head done. Just cleaned up the ports. nothing special. Lapped the heads. Just have to lap the valves next and reassemble

The turbo has arrived after its tour across the country. It will be custom rebuilt for this application.

"This is a used Airesearch TO4 turbo from Garrett. This came off of an 1987 Saab 900 Turbo"

Pete

[This message has been edited by PBJ (edited 02-06-2005).]

quote Originally posted by Will: Nylon manifolds are QUITE strong. The Northstar was the first major application that used a composite manifold, so GM was a little wary of the way it might behave; hence they included the sneeze valve. LS1 manifolds do not have a sneeze valve and are tested at 80 psi. Nylon 66 is not known as a fragile material. If you're THAT worried about it, add a stronger spring behind the sneeze valve. You just need to keep it closed at your max boost level.

An engineer who worked on the northstar - "good thing it [the flapper valve] is there or the plastic intake would have fragged by now." - in reference to an intake backfiring problem. I doubt a backfire event would pressurize the intake >50psi. That's quite a large volume. In regards to installing a stronger spring..... I don't see how the flapper would seal properly under boost. Vacuum is a much different animal than boost. AFAIK, nobody has used the 95+ intake manifold for boost on the northstar. There must be some reasoning...

quote Originally posted by ryan.hess: An engineer who worked on the northstar - "good thing it [the flapper valve] is there or the plastic intake would have fragged by now." - in reference to an intake backfiring problem. I doubt a backfire event would pressurize the intake >50psi. That's quite a large volume. In regards to installing a stronger spring..... I don't see how the flapper would seal properly under boost. Vacuum is a much different animal than boost. AFAIK, nobody has used the 95+ intake manifold for boost on the northstar. There must be some reasoning...

I bet the engineer who did work on the northstar wasn't named "will"

so what should cam timing be set at for boost???
any ideas?

I am going to use the intake manifold. I have some ideas on how to fix it for 5psi

quote Originally posted by Bill Strong: so what should cam timing be set at for boost??? any ideas?

4 deg advance on stock intake camshafts.

Is that info from Alan Johnson or your own research?

This is from Emails with Alan-yes. Would you go abit further than 4 degrees or something different?

Pete

quote AFAIK, nobody has used the 95+ intake manifold for boost on the northstar. There must be some reasoning...

Mine has the stock '96 plastic intake with a turbo and the flapper sealed shut. It's still in one piece.

Jon

Pete your going to need a couple of these

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7956522551&category=33643&sspagename=WDVW

Steve

quote Originally posted by PBJ: It will be custom rebuilt for this application.

Any idea on the specs you want, or how much it'll cost?

btw how much was the used turbo? $50 on ebay?

quote Originally posted by ryan.hess: Any idea on the specs you want, or how much it'll cost? btw how much was the used turbo? $50 on ebay?

The turbo was $87.00 on ebay and it saved me $150.00 core charge for the rebuild from www.cherryturbos.com . The Turbo will be completely custom, and modified on a lathe. I did not go to the company with spec for a turbo, Supplying me with the correct turbo is what I am paying them for. I went to them with what I was using the turbo for and they designed it. They will be modifying the housings and impellors. The only part remaining from the T3 I supplied them is the center housing, which may or maynot be the housing used for our turbo. The cost for this custom turbo was quoted at $1100.00 to $1400.00. One of the major difference with this turbo is that it will be designed to have high flow but run efficiently low boost pressure, since the engine will be run between 3 and 5 psi boost.

Pete

[This message has been edited by PBJ (edited 03-03-2005).]

quote Originally posted by PBJ: This is from Emails with Alan-yes. Would you go abit further than 4 degrees or something different? Pete

I think he's done all the research to know what's best.
Changing cam timing on the N* is not exacly easy...

quote Originally posted by Will: Changing cam timing on the N* is not exacly easy...

It was for me All I did was let Beck (Her86GT) know the address to mail her sprockets to and include some form of payment. Now if only a Holley 950 was that easy.

Pete

Steve and I played a bit more with the engine tonight. Its getting there.

[This message has been edited by PBJ (edited 03-02-2005).]

Did you spill something on the block? It's not supposed to be black

the caddy teck who build my N* also used timeserts on the main crank bolts in addition to the head bolts
I think thats a very good idea for any hi-po motor with an alloy block

I would use studs on any bolt location just so you donot have to mess with removing it again

what did the IRL guys use for lifters [solids?] in the olds version they raced at indy
as I can't see no 12k rpm on hyd lifters
no matter how strong your springs

BTW as IRL guys are in homestead this week I will go down and try to pump them for info
on the race versions of the olds/N* that is now old junk parts to them
as far as I know no other seiresis useing the olds version of the N* to race now
and they may be willing to sell some bits cheap
like valves or lifters and springs even ported heads or manafolds
or at leased know who now has these motors and spare bits

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Question wonder and be wierd
are you kind?

[This message has been edited by ray b (edited 03-03-2005).]

The race engine has nothing in common with the street engine and (used to) cost $80K...