#181  
Old 10-19-2023, 07:48 AM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,899
Default

Interesting. I think I saw somewhere that one is 7/8" diameter, and another is 15/16" diameter, but didn't save the source. I flipped around yesterday for a short digging on this some but found no conclusive info.


.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #182  
Old 11-15-2023, 08:23 PM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

Last month the engine tossed the belt - again. So after I returned from vacation I examined it closer. A straight edge across the power steering pulley showed it to be 1/2 off, and a chip in the composite pulley.

So I bought a pulley installer/puller and a new GM pulley, shimmed one of the legs 0.054" and will see what happens this time. I wanted to use the 3/4 ton mount but they are out of stock everywhere.

  #183  
Old 11-18-2023, 01:24 PM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

Belt seems ok so far.

15-1/2 mpg, in town driving only. Once belt shows to be reliable will try a run up to Santa Fe.

  #184  
Old 11-21-2023, 08:34 PM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

Another PY'er had asked about the cam I am currently running - GM# 12664572. It was touted as a non-DOD LT1 cam, 200/207 @116.5.

Greaseball noted to me to check this cam out again. I was horrified to discover somebody at GM goofed, the real spec's are 189/223 at 120 separation!

I emailed the vendor, Michigan Motorsports, about this issue. This was their reply:


Good morning,

Back when you purchased that camshaft, everybody (including ourselves and several large GM parts retailers) who was selling that LT5 camshaft had it listed as being similar specs to the L86/LT1 camshaft, as that is what the information everybody had at the time showed the specs as being. I'm not sure if GM changed the camshaft now that the LT5 is just a crate engine rather than a production car engine, or if the information everybody had was wrong all along, but it was later discovered when one of the larger companies selling that camshaft measured it on one of their Andrews camshaft machines that the specs were quite a bit different than thought and we all updated our listings to show the 188/223 specs that they informed us of.

At that time we went ahead and stopped selling that camshaft since it wouldn't be a good fit for most of our truck/SUV customers even though we hadn't heard any complaints from anybody about how it ran in those engines at all.

We now sell the Texas Speed camshaft in the link below for the L86/LT1/LT4 DOD deletes. To use that camshaft on an L84, you would need to upgrade to LT1 style valve springs as well.

If you don't want to run the LT5 camshaft, you can return it to the address below for a refund or store credit.

The LeMans has of course been running for the last 6 months with this wrong cam. Other than the wide separation, it seems to be a Gen V version of Comp's Thumper.

Yuck.

So I will replace it and now am leaning towards the L8T cam, which is the same as the 5.3 (193/199) but with DOD delete. The L8T is a 3/4 and 1 ton truck version of the Gen V but in 6.6 liter. The smaller 189 does indeed move the LeMans briskly and with less exhaust duration should get better power and mileage.


Last edited by Scarebird; 11-21-2023 at 08:39 PM.
  #185  
Old 11-21-2023, 11:34 PM
greaseball greaseball is offline
Junior Member
 
Join Date: Jul 2009
Posts: 17
Default

Quote:
Originally Posted by Scarebird View Post
Another PY'er had asked about the cam I am currently running - GM# 12664572. It was touted as a non-DOD LT1 cam, 200/207 @116.5.

Greaseball noted to me to check this cam out again. I was horrified to discover somebody at GM goofed, the real spec's are 189/223 at 120 separation!

I emailed the vendor, Michigan Motorsports, about this issue. This was their reply:

Thank you for helping me confirm what I feared, Scarebird. Also, thank you for posting the reply from the vendor that you used for your LT5 cam.

Ive started a new thread on this subject:

https://forums.maxperformanceinc.com...d.php?t=870470

The Following User Says Thank You to greaseball For This Useful Post:
  #186  
Old 11-22-2023, 07:37 AM
HWYSTR455's Avatar
HWYSTR455 HWYSTR455 is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Manassas, VA
Posts: 14,899
Default

In the later years, Pontiac had some wide LSA cams, 116-118 or so, and suspect it was due to plugged up exhausts with cats, but there was not much trade off on power without other mods, so...

Some of the earlier Crane cams used 114-116 LSAs and were good performers, but sure there were specific reasons for those numbers.

On what is basically a 327, with tall intake ports, I suspect there was some concern about intake velocity, and sure they did a ton of testing. (for all-around performance).

As for documentation, engineers are pretty terrible at docs, and generally dread doing them. Most are rushed, lack grammar, and things (tech/assembly) change along the way. Discernment is always advised.

Nice catch by the way, and the discovery & sharing will live forever on the internet.


.

__________________
.

1970 GTO Judge Tribute Pro-Tour Project 535 IA2
http://forums.maxperformanceinc.com/...d.php?t=760624
1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car
https://forums.maxperformanceinc.com...ght=procharger
Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be
  #187  
Old 11-22-2023, 10:22 AM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

Greaseball brought this to my attention.

The Following User Says Thank You to Scarebird For This Useful Post:
  #188  
Old 12-16-2023, 01:12 AM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default Update:

Nothing really good to report. These motors have the oil pump in front - driven radially by the crank. The crank timing gear is behind the pump.

You can almost get the timing chain off the cam gear. There is a youtube where this was done, but I suspect the chain has a bit more stretch than the 2,000 mile chain I have. The chain has a guide and tensioner assembly. If GM made it 1/4" shorter the chain would come off the cam gear easily and then the cam gear, retainer and cam would fly right out.

But it is not, so the engine has to come out to pull the pan to pull the pump, etc.



Maybe when the GM tech pulls the cam to replace for DOD lifter damage the truck pan will drop enough to pull the pump... maybe.

Anyhoo, the motor was pulled (manual trans) and offending cam was removed.
New cam was installed and engine resealed. I took the time to paint it Duplicolor DE1610 which is supposed to be for 1959-65's but looks a hell of a lot more like 1971-73. The harness was repaired by SwapTime and new mounts will hopefully raise the motor 0.200" and then the oil pan will clear the tie rods and regain turn radius.

Attached Thumbnails
Click image for larger version

Name:	Blue motor.jpg
Views:	427
Size:	80.2 KB
ID:	625015  

The Following User Says Thank You to Scarebird For This Useful Post:
  #189  
Old 03-08-2024, 10:07 PM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

One of the other issues I was having was burping the cooling system. I belatedly realised that the upper hose was creating an air pocket as it was almost 4" higher than the radiators inlet port.



Some research initially revealed nothing for hoses, then I got lucky. I was going thru LS powered vehicles and noted this Dayco 70815 hose from a 2010 Camaro. It used an offset hose in 1-1/4" ID, so it would clear the power steering pump and fan also. They are $11 on Amazon.



I was able to trim it and the 1969 GTO upper hose to sit at the same level as the inlet. I will fire it up tomorrow when it stops raining and see how it burps the air.



Attached Thumbnails
Click image for larger version

Name:	Upper hose before.jpg
Views:	290
Size:	60.8 KB
ID:	630095   Click image for larger version

Name:	Upper hose after.jpg
Views:	299
Size:	48.8 KB
ID:	630096   Click image for larger version

Name:	Top view.jpg
Views:	315
Size:	52.7 KB
ID:	630098  


Last edited by Scarebird; 03-08-2024 at 10:28 PM.
  #190  
Old 03-24-2024, 03:22 PM
GTO-relic GTO-relic is offline
Senior Member
 
Join Date: May 2021
Posts: 157
Default

Quote:
Originally Posted by Scarebird View Post
Belt seems ok so far.

15-1/2 mpg, in town driving only. Once belt shows to be reliable will try a run up to Santa Fe.
I'm going to play devil's advocate here, from the practical standpoint,
you went from a 440" Pontiac V8, to an LS with 376" or less, correct ?
raving about mileage from a motor that is 64" or more smaller, doesn't mean you got a better motor.
you just got a new, smaller motor.
the old one you had, albeit larger, was outlawed by EPA back around 1979, it couldn't meet future mileage, EMISSION standards.
question- why are you building an emissions/mileage standards engine ?
the beauty of these old cars, you can put an antique plate on them, never get registration or inspection again, and the insurance goes down to $50 a year for basic liability. what about that savings ?
the money you spent on the build would buy a lot of gas even at $8 a gallon, with the old motor.
just remember this, they call those LS motors by liter names, 5.3 5.7 6.2
because numbers like 376 don't sound very impressive.
Pontiac had a 6.5 liter back in 1964. that's .3 liter more than the 6.2 LS
honestly I don't think it was a good move. it's like doing touchup work on the Mona Lisa painting
it just completely devalues and ruins what it is, historically.
having said that good luck with the LS- I never found out what size it was, because the original link to Ebay has long expired. 15.5 mpg ?
honestly you could have got that mileage easily with a 326-350-389 Pontiac. with a carburetor. I used to get 14mpg with a 400 and a Qjet, in a Firebird.
my brother in law used to drive a Nova with a 350 Pontiac and Qjet to work all week. he got 18mph highway, with 3.08 gears, Saginaw 4 speed.
I bought a 1994 Mercedes V12 6 liter, used for $1500
it can do 180mph on the highway, factory 402hp, yet gets 18mph on the highway. 6 liter. 12 cylinder. if you want a Euro cruiser, I'd suggest just buy one.
these are all friendly suggestions. no harm or foul intended. just objective opinion. the LS in my opinion, is not the better engine.
it's the legal engine, what the EPA allowed people to have since 1998, from GM.

  #191  
Old 03-24-2024, 04:01 PM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

You are willingly missing the point here.

10mpg is unacceptable to me - here or in Europe. My old 462/96/Q-Jet/2801/TH-200-4R/3.55 combo got 17 - once. Usually closer to 14. Gas is $10/gallon where I am going and the whole 150 mile range thing won't work.

Math shows the LT change will pay for itself in about 700 gallons at $10/gallon vs 440 - power is equivalent.

  #192  
Old 03-25-2024, 08:26 AM
JSchmitz's Avatar
JSchmitz JSchmitz is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Union, MO
Posts: 2,265
Default

Moderator, please don't allow LS bashing in this section.

Keep up the good work Scarebird!

  #193  
Old 03-25-2024, 10:02 AM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

Thanks, Mr. Schmitz.

Some people don't like things that are not what they know and they tell you.

  #194  
Old 03-25-2024, 10:37 AM
JSchmitz's Avatar
JSchmitz JSchmitz is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Union, MO
Posts: 2,265
Default

Quote:
Originally Posted by Scarebird View Post
Thanks, Mr. Schmitz.

Some people don't like things that are not what they know and they tell you.
You're welcome! You do top notch work.

He's just explaining to you that you're too dumb to evaluate engines and are ruining your car. Just "friendly suggestions". LOL! Some people think it's ok to kick you in the balls as long as the apologize afterwards. How about just stay out of this section of the forum instead?!?!

  #195  
Old 04-13-2024, 11:25 PM
kpbrown31 kpbrown31 is online now
Senior Member
 
Join Date: Feb 2023
Location: NE Kansas
Posts: 162
Default

I imagine upgrading the AC system in these old cars when using an LS is much cheaper than running a vintage air setup? That's on appeal to me. I'm torn between sticking with old carbureted Pontiac vs an LS setup. Right off the top I feel like a guy could save a couple thousand with an LS by using the AC setup they already have, plus headers are much cheaper compared to my only option of a 1k pair of Doug's headers.

  #196  
Old 04-14-2024, 12:18 AM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

Ac-wise is hard to say. As you note damn near every car now built has AC so the bracketry is available.

I am still tempted to fit it once the move is done - I will see what the climate is like during the dog days.

  #197  
Old 05-27-2024, 02:38 PM
Scarebird's Avatar
Scarebird Scarebird is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: ABQ, USA
Posts: 5,061
Default

After changing out the incorrect cam in the Gen V 5.3 the first mileage test (all city type driving) ended up with 19.39 MPG.

This with an engine that Holley dynos out at 405 horsies. I can live with that.

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:51 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017