Pennock's Fiero Forum
  The Construction Zone
  Northstar rebuild: Will style (Page 25)

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version

This topic is 25 pages long:  1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25 
Previous Page | Next Page
next newest topic | next oldest topic
Northstar rebuild: Will style by Will
Started on: 12-29-2003 09:00 PM
Replies: 969 (69329 views)
Last post by: Will on 01-03-2021 09:01 PM
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post12-26-2020 12:47 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
My dad and I did poorly thought through mods to the right hinge box years ago... Time to fix those.

Prior state. I got the left part removed this weekend... got most of the spotwelds cut on the right part, but there are 2-4 I can't get to without a drill extender.





Before I pulled the engine out, I also scribed the mark shown depicting where the surface of the cam cover actually falls. This corresponds to the top of the hole in between the studs on the original hinge box.

I'm installing the hinge box that FieroGuru removed from his car, so I'm putting a famous piece of hardware into my franken-rig.
IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post12-26-2020 12:50 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post

Will

13573 posts
Member since Jun 2000
I got the rest of the hinge box off over the weekend, but forgot to snap a pic.

My rings came in! Wooooot! SS, PVD, gapless, lapped, gas ported. :-D



I measured their thickness and found that Total Seal has really upped their QC game over the years. These were lapped, but didn't look like it arriving in this packaging. However, they all mic'd in the 0.0578" to 0.0580" range, measuring 5 points per ring. 0.0002" over the whole set! That lets me talk to Rebco about how wide to make the grooves. SS, PVD, gapless, lapped, gas ported. :-D

I also have the laser cut blanks for the Getrag throw out bearing holder for the PTT 7.25" dual disk clutch.

IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post12-26-2020 12:55 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post

Will

13573 posts
Member since Jun 2000
Soo... What's been going on with the build?

I have the new rings, but need to get the pistons shipped for re-grooving the top groove. I've had a couple heavy weeks at work and haven't gotten that done yet.
I did this, however:



Mmmmm... PPPC titanium piston pins @ 78 grams. They're DLC coated to avoid problems with titanium galling, and also have steel end caps to avoid that same problem where they touch the locks.
I double checked the weight of all the parts, and of course found that the idiot shop assistant had not added the weight of the top ring into the recip component of the bobweight. Sigh. Apparently he didn't look at what he was weighing either, or he would have noticed that the top rings were NOT THERE. I can get that my failure to remove the steel pins was a failure to idiot proof what I wanted to get done... But for someone to weigh an incomplete assembly and not actually check off all the pieces that are supposed to be there, I have a much tougher time assigning that to anything but negligence.
The top ring is 9.7g; since there are two of them per throw at a 50% recip factor, the bobweight is off 9.7g.

I started this thread on Speed-Talk: https://www.speed-talk.com/...pic.php?f=15&t=62405
The collective opinion of builders there being that 10 g is a tiny effect and I probably won't notice.

Also, since the rings came in between 0.0578 and 0.0580, I started this thread about top ring side clearance: https://www.speed-talk.com/...pic.php?f=15&t=62408
Consensus seems to be that side clearance can be tighter since my rings are gas ported. The discussion of back clearance is interesting too. I need to measure my rings to give Rebco their actual radial dimensions instead of the radial dimension of the prior set... THEN I'll be able to send the pistons off

I'm at drill this weekend, so no movement on that until Monday.
IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post12-26-2020 12:58 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post

Will

13573 posts
Member since Jun 2000
ALSO:

It may not be super obvious what this is:







But it's a template to let me verify that I have the dimensions of the Y2K+ manifold correct, in order to modify the early heads to accept it.

The first photo is verifying it fits the manifold. The next photo is of the template on a pair of roller cam (Y2K+) heads verifying that I have that bolt pattern right.

The third photo is with the right head a roller cam head and the left head a flat tappet head. Three of the holes are close enough with only the end holes needing to be updated. You can see where the old intake flange sticks out from under the template. This is the material that needs to be trimmed off before the manifold will fit. Of course I also need to counterbore, drill & tap the mounting holes for the new manifold, but I have those close enough.
It was interesting to find that the template just clears a feature on the block when used with the roller cam heads, but when used with the flat tappet heads it doesn't clear the feature. That means the intake flanges on the roller cam heads are ~1/4" higher than the ones on the flat tappet heads.

I also realized I didn't snag a photo the template with both flat tappet heads.

I'm not going to machine using the template. I just had the template made as an easy way to verify that I have all the dimensions involved basically right. I'll make a machining drawing and use the DRO on a mill to actually cut the flanges.
IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post12-26-2020 12:59 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post

Will

13573 posts
Member since Jun 2000
Been a little while since I posted, so this'll be a longer summary.

Following up on checking the intake manifold template, I put my mockup block with actual cylinder heads on a mill and went to town. I eyeballed it square, then used a gauge pin in the end holes on the manifold bolt patterns to properly square it up in the mill.





There are two steps that have to happen to modify the heads for the later manifold. The first is modifying the flanges so the manifold will drop in place. The second is drilling the alternate mounting holes so the manifold will bolt down. I had all that figured out in the template and had to do it all in this one setup on the mill. The width of the space in which work was to be done was winder than the Y-axis travel of the mill table, so I had to slide the head in/out to get everything. Because of that I had to do everything on the right bank first, then everything on the left bank.

In starting on the hole pattern, one of the first things that becomes obvious is that the flywheel end intake ports are over top of water jacket passages out of the heads to the waterpump. This means you can't drill indiscriminately into/through things.



This is a photo into that port. The bulge down from the top is the boss for the original manifold bolt hole.
While cogitating on how to deal with that, I went ahead and scalloped the flanges.









Of course, once I put the effort into scalloping the flanges, it became fairly obvious that I should have just buzzed down the entire row instead of carefully sculpting them.





Moving on to the manifold pattern, I was able to drill most of the holes uneventfully. Only two needed to be counterbored because they ended up on the edge of a sloped surface.





I had to very carefully control the depth of the one over top of the water jacket passage, but there's enough of a boss behind the original boss that I was able to drill a usefully deep, although depth-limited hole at that location.
Where there aren't cooling jackets under the flanges, there's actually free space. Most of the holes drilled straight through, which would make tapping them easy. I didn't tap them this time around, though. One of the holes ended up with a surface below the flange halfway through the diameter of the hole. The drill walked and wobbled the hole before I realized it. I was very careful about drilling the other hole affected by this issue after that.





Mods completed:



Even with all of that work, the manifold doesn't quite sit down on the intake flanges.
As this point I graduated from planned/engineered mods to the fit/futz cycle.
I had to do some extra whittling... which I was fine with doing since this is my mockup block.





After these mods, the manifold finally sat on the intake flanges without running into anything. Unfortunately I flaked on grabbing a photo.
As I believe I noted in playing with the template, one of those things was to raise the port flanges by 1/4-3/8". That means the later manifold say lower in the V on the early heads than it did on the late heads. That's where the block interference came from. After I was able to get the manifold to have clearance everywhere and sit down on the flanges, I tried to fit check with the starter.



Note the gap between the manifold and the intake flanges.
Of course, GM changed a LOT of things in the intake port and flange configuration on the cylinder heads when they went to the later manifold.
Ooops. Not really anything reasonable to do about that. Back to the drawing board. At least now I understand what needs to be done for this, and I've discovered one more way that won't work. Look out, Edison.
IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post12-26-2020 01:03 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post

Will

13573 posts
Member since Jun 2000
My actual block is still at the machine shop. They tried to have it done by Christmas, but the operator for one of the machines got sick. He didn't say if it was COVID or not. Looks like it'll probably be ready the week of the 4th, though.

After I did the mods shown above, I dropped the heads off with the Cerakote guy. I need to figure something out with him, as he was saying he'd need a warm day to do the work. Maybe I just need to haul a space heater over there.

I ordered the Cometic head gaskets. They have a 6 week (!) lead time right now... Ooops.

I started actually discussing my clutch application with PTT. They also provided the clutch for Wcapman's Northstar, but there are some key differences between our two swaps such that his setup won't bolt into my car. I had my flywheel packaged for a 2x0.250" configuration with 2 organic disks 0.250" thick. PTT recommended their cerametallic friction material, even for a street car. He said that PTT's material has a lower coefficient of friction than others, but they clamp it harder, resulting in a clutch that's easier to modulate. Their blank flywheel is 0.840" thick, but will work in the Getrag with a 2x0.105 clutch, which has the cerametallic lining. Their flywheel is under 5#, but is just the button, so once I add flex plate and ring gear it will probably be around 8#. The one I made is 11#, so this will be lighter.

Also, the engineer didn't like that the material under the bolt heads in my flywheel was only 0.270 thick in something other than 4140. I think it's A36 structural steel. My flywheel has the bolt holes down in individual counterbores, so the material around each bolt is thicker. Their flywheel has a 0.270 flange without any counterbores. Given these differences, I'm not so sure that his concerns are valid, but don't **** around with flywheels.

Anyway, it'll be nice to be able to buy something and assemble it rather than having to make something every time I turn around.

https://powertraintech.com/...oducts/flywheel-7-25

IP: Logged
RCR
Member
Posts: 4298
From: Shelby Twp Mi
Registered: Sep 2002


Feedback score:    (7)
Leave feedback





Total ratings: 102
Rate this member

Report this Post01-01-2021 11:20 AM Click Here to See the Profile for RCRClick Here to Email RCRSend a Private Message to RCREdit/Delete MessageReply w/QuoteDirect Link to This Post
Hi Will,
Just a curiosity question, coming from someone that's worked on his project really for the fun of it: Why do you put so much effort into the Northstar when there are arguably better motors you could play with?

Not trying to start a flame war, just looking into the mind of another Fiero maniac.

Take care...

Bob
IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post01-01-2021 05:04 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm not smart enough to know when to quit?

I originally picked the Northstar because it would bolt up to the transmission and fit with minimal mods to the engine or body. The LS's pretty much just didn't fit because of the accessory drive and still needed an adapter plate. The LS4 bolts to the transmission, but still requires work for the starter and water manifold clearance. The Northstar can also turn 8500 RPM a lot more easily than an LS or traditional Chevy.

I'm still at it because rebuilding an engine *SHOULD* be easy, right? Not like I've had TWO shops fail at getting the cylinder hone right or anything...

I *should* be able to pick the block up from ProMar at the end of next week and get the short block assembled... finally.

[This message has been edited by Will (edited 01-01-2021).]

IP: Logged
sourmash
Member
Posts: 1637
From:
Registered: Jul 2016


Feedback score: N/A
Leave feedback

Rate this member

Report this Post01-01-2021 07:36 PM Click Here to See the Profile for sourmashClick Here to Email sourmashSend a Private Message to sourmashEdit/Delete MessageReply w/QuoteDirect Link to This Post
Once you're so deep, you might as well keep on going.
The engines were worked up and put into sand rails. Has anyone looked into scavenging one of those abandoned projects for a Fiero?
IP: Logged
Will
Member
Posts: 13573
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post01-03-2021 09:01 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
That's pretty much what I'm building.
IP: Logged
Previous Page | Next Page

This topic is 25 pages long:  1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25 
next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock