Northstar rebuild: Will style (Page 6/119)
Will FEB 07, 09:01 PM
Alan seemed to be confident that he could grind custom roller cams for me if I supplied him 8620 steel blanks. I'd be more concerned that he wasn't on the absolute cutting edge of roller cam lobe development. I'd be more inclined to get cam specs from one of the leading LS1 cam grinders and have him cut cams to those specs from blanks I supply.

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'87 Fiero GT: Low, Sleek, Fast, and Loud
'90 Pontiac 6000 SE AWD: None of the Above

Do that again, only mean it this time

jstricker FEB 07, 11:08 PM
I think you already know this, but on the off chance you don't, the piece from CHRFab is NOT a bypass, it's a remote filter adapter and simply a hunk of machined aluminum (nicely machined hunk, but a hunk nonetheless). It has no bypass capabilities, at least the one in my hot little hands doesn't. I only mention it because you keep calling it a "bypass".

John Stricker

quote
Originally posted by bushroot:

I'm not a machinist. I'm an electrical engineer. Although I do have some machining experience, I would rather pay someone for these parts. My time is worth something to me. The prices quoted by Alan were $55 for the oil bypass and $210 for the mounts. The bypass is a steal. I like his mounts and it would take me quite a while to replicate something like that on a manual mill. I'd rather have someone else do the cams and heads. You forget, mine is the 2000+ Northstar. Alan didn't express enough confidence in his experience with them to justify his pricing. As much as it's his right to charge as much as he likes for his services, it's my right as a potential customer to decide where I'd like to place my trust and money. This isn't intended as an insult towards Alan in any way, so I'd appreciate if it isn't construed as such.
Will FEB 07, 11:18 PM
Yes, that should definitely be noted. The N* flows 12 gpm of oil at redline, and without a bypass you'll need a LOT of filter, or an external bypass, to not restrict the oil flow. If you're going to use the Caddy filter, fine, but if you use a Chevy filter, remember that they do NOT have bypasses in them and you'll need TWO Chevy truck filters in parallel to not restrict the flow.

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'87 Fiero GT: Low, Sleek, Fast, and Loud
'90 Pontiac 6000 SE AWD: None of the Above

Do that again, only mean it this time

bushroot FEB 07, 11:30 PM

quote
Originally posted by jstricker:

I think you already know this, but on the off chance you don't, the piece from CHRFab is NOT a bypass, it's a remote filter adapter and simply a hunk of machined aluminum (nicely machined hunk, but a hunk nonetheless). It has no bypass capabilities, at least the one in my hot little hands doesn't. I only mention it because you keep calling it a "bypass".

John Stricker


I (obviously incorrectly) called it a bypass. Yes, I know it's only an adapter. The plan was one of these. http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1791&prmenbr=361


Edit: fingers no worky worky when cold

[This message has been edited by bushroot (edited 02-07-2004).]

bushroot FEB 07, 11:55 PM

quote
Originally posted by Will:

Alan seemed to be confident that he could grind custom roller cams for me if I supplied him 8620 steel blanks. I'd be more concerned that he wasn't on the absolute cutting edge of roller cam lobe development. I'd be more inclined to get cam specs from one of the leading LS1 cam grinders and have him cut cams to those specs from blanks I supply.


If you manage to get some MY2000+ cam blanks, or decide to make some...LET ME KNOW! I contacted GM Performance, they couldn't (or wouldn't) get me a set of billets. For now, I'm going regrind. I was thinking I'd keep the stock lift (from what I'm told, you can cut the bottom of the lobe to increase lift). From what Terry (the guy doing my trans) has worked out for me, I'll want something like 288/294 for duration. We'll see if that's possible. That should get me to 8500 RPM without it falling on its face. As for the valve springs, he's not so sure I need 100lb. springs, so the jury is still out on that one. Did you know that F1 cars run about 60lb. valve springs and are capable of running 17,000 or so RPM? Also, something of interest, I did both piston and crank speed calculations. The Northstar should live fine around 8 grand. I'm sure this is something Alan had already figured out. I'm curious why they built such a safety margin into the engine.
Will FEB 07, 11:56 PM
that's what I'm going to be using for my break-in oil system....
jstricker FEB 08, 01:49 AM
Their valves are much, MUCH lighter, for one thing. Mostly titanium. Makes a lot of difference.

I figured you already knew about the adapter not being a bypass, but you know how it is, unless you say something, you never know.

The filter adapters you linked to have served me well in the past, I used to use the same ones on Big Block Chevy's in race boats. They don't have a bypass in them either. That's fine, just make sure you change them often and don't believe the Northstar advertising that you can go 10K miles before an oil change. The Northstar has a very high volume oil system and a lot of oil is going to be moving through them, so use good filters.

John Stricker


quote
Originally posted by bushroot:


If you manage to get some MY2000+ cam blanks, or decide to make some...LET ME KNOW! I contacted GM Performance, they couldn't (or wouldn't) get me a set of billets. For now, I'm going regrind. I was thinking I'd keep the stock lift (from what I'm told, you can cut the bottom of the lobe to increase lift). From what Terry (the guy doing my trans) has worked out for me, I'll want something like 288/294 for duration. We'll see if that's possible. That should get me to 8500 RPM without it falling on its face. As for the valve springs, he's not so sure I need 100lb. springs, so the jury is still out on that one. Did you know that F1 cars run about 60lb. valve springs and are capable of running 17,000 or so RPM? Also, something of interest, I did both piston and crank speed calculations. The Northstar should live fine around 8 grand. I'm sure this is something Alan had already figured out. I'm curious why they built such a safety margin into the engine.
Will FEB 08, 09:24 AM
F1 cars have the absolute minimum valvetrain mass, as jstricker says. Also, I'm sure that VERY, VERY few people have ANY real knowledge of F1 valvespring rates. I would be pretty surprised if "the guy doing your trans" is one of those people, unless he has a lot of other qualifications.
I thought they closed the valves pneumatically anyway. If they do use springs, F1 springs are going to be tapered and behived and wound with oval wire and all the other tricks to get max revs from minimum spring rate.

AJ's website claims that his springs work with stock retainers, which means they are most likely not tapered. Northstars also have hydraulic lash adjusters that reciprocate with the valve. They add a bit of mass and F1 engines CERTAINLY will not have them.

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'87 Fiero GT: Low, Sleek, Fast, and Loud
'90 Pontiac 6000 SE AWD: None of the Above

Do that again, only mean it this time

bushroot FEB 08, 03:44 PM
What, do I have to get a copy of his resume for you guys? If you’re interested in having work done by him, E-mail me. I’ll get you the contact info. I’m sure he’d be more than happy to fill you in on his credentials. This guy worked on the Cosworth/Ford F1 project in the late 70's/early 80's, he knows Jack Roush and John Quaife by first name. Why don't you ask him if he's qualified?

[This message has been edited by bushroot (edited 02-08-2004).]

Will FEB 08, 06:21 PM
Oh yeah, the guy who's installing the external lube and such... Ok... I forgot who the "guy doing your trans" was...

Needless to say, F1 has changed a LOT since the early '80's. F1 engines were in the 10-12 thousand RPM range back then. Now adays they're using pneumatic pressure to close the valves.

http://www.indiacar.com/index2.asp?pagename=http://www.indiacar.com/nfs/technical/pvengine.htm

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'87 Fiero GT: Low, Sleek, Fast, and Loud
'90 Pontiac 6000 SE AWD: None of the Above

Do that again, only mean it this time