#1  
Old 02-12-2024, 07:16 AM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default Poured valley brace thoughts

Would this cause any breathing issues by putting extra pressure into the crank case?

My engine builder has stripped down the motor to find the problem with it pushing oil out the dipstick. It did what I told him was happening on his dyno, got to 3000rpm and pushed oil out. He says that all the bores and rings are perfect and measure correctly. He did his own leakdown test before and got 15% on 3, 12% on 4 and 7 the rest were 9%.

I had the same set up with my solid roller cam and that had some leaks around the pan but nothing from the dipstick.

Could the lack of holes in the poured in brace be restricting the breathing?
Attached Images
 

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #2  
Old 02-12-2024, 07:53 AM
Formulas Formulas is offline
Ultimate Warrior
 
Join Date: Dec 2004
Posts: 2,642
Default

there is still the hole in the front of the block by front cam bearing.. pressure under piston can travel through timing cover and vent to lifter valley .... is there no way for valley oil to drain back down from top of lifters with the pour? since block is tilted back could be alot of trapped puddled oil there making it hard to get consistant level readings... i cant tell from picture

  #3  
Old 02-12-2024, 07:59 AM
steve25's Avatar
steve25 steve25 is offline
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 14,535
Default

You need to repost that picture because we can't openit up bigger, but non the less if that valley is now fully sealed and was not before, then yes that is why your pushing oil and dip sticks out.

If that valley is now mostly sealed a header evac system will not work so you need to run a vacuum pump or drill and put vent tubes in there like they with BBC motors.

I am really questioning that builder and his thinking / guidance now after seeing this.
Attached Thumbnails
Click image for larger version

Name:	D80915C2-CB49-4188-A4D9-9E7D028A9972.jpg
Views:	207
Size:	43.8 KB
ID:	628421  

__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #4  
Old 02-12-2024, 09:40 AM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

The brace was done on the last build by Len Caverly.
Attached Thumbnails
Click image for larger version

Name:	Resized_20170225_191136.jpeg
Views:	281
Size:	68.3 KB
ID:	628422  

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #5  
Old 02-12-2024, 09:47 AM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Steve, how and where are those tubes fitted?

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #6  
Old 02-12-2024, 01:27 PM
Dave Polichena's Avatar
Dave Polichena Dave Polichena is offline
Chief Ponti-yacker
 
Join Date: Mar 2004
Location: Lake Worth FL
Posts: 546
Default

461, the valley would have to be drilled and tapped for the tubes. 1/4 pipe and stand up them straight up

__________________
Dave Polichena
  #7  
Old 02-12-2024, 02:31 PM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Thanks Dave, do you think they would help or are needed?

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #8  
Old 02-13-2024, 06:13 AM
chuckies76ta's Avatar
chuckies76ta chuckies76ta is offline
Ultimate Warrior
 
Join Date: Jun 2004
Location: Canada
Posts: 3,055
Default

So this is why the oil is blowing out the dipstick. Makes sense now. Pressure in the crank case has to go somewhere.
https://forums.maxperformanceinc.com...d.php?t=871548

__________________
68 Firebird. IA2 block, 505 cu in, E-head, Solid roller 3650 weight. Reid TH400 4:11 gear. 29" slick.
Best so far 10.12@133 mph. 1.43 60 ft.
76 Trans am, TKX .81 o/d, 3.73 Moser rearend,
468 with KRE D-ports, Doug headers, 3" Exh.
  #9  
Old 02-13-2024, 07:31 AM
steve25's Avatar
steve25 steve25 is offline
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 14,535
Default

What does the OP exactly mean by “ he did his own leak down test before “?
Is before in reference to before this time on the dyno to prove out the dip stick issue, or before the motor was first put in the car?

This Seems to all have been discussed before in a previous post that you made, but to me that 15% leakage even on a fresh bore and unseated rings is high regardless of the builder saying that everything measures fine.

__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #10  
Old 02-13-2024, 10:49 AM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Steve, yes he did a leakdown test before running it up to 3000 to see for himself if it came out the dipstick, which it did.

Chuck, do you think that brace is the cause? It's the same set up as when I ran the solid roller when it was built originally by Len and Shaker. It always leaked from the pan gasket before, but perhaps the rings sealed better when they built it than now on this rebuild.

If that's part of the problem, short of removing the epoxy or drilling vent holes, would putting a breather where the valley pan pcv grommet is, relieve some pressure? It's currently plugged as I'm not running a pcv.

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #11  
Old 02-13-2024, 11:05 AM
Formulas Formulas is offline
Ultimate Warrior
 
Join Date: Dec 2004
Posts: 2,642
Default

Observation... a lower HP/torque engine with a leakdown rate of 5% will dump less volume in the crankcase than a higher HP/torque engine at 5% leak rate

above rings cylinder pressure is greater with more HP 5% of 1000psi is a greater volume than 5% of 100psi

your oil pan only leaking before could of been a tell now magnified with more power now blowing out of dipstick

Also with aluminum heads there is less room for crankcase venting to valve covers due to fewer voids / holes in the pushrod areas compaired to old iron

something i would do if my dipstick was blowing out, i woul back total timing off say 4 degrees to make sure i wasnt over advancing with a new build

  #12  
Old 02-13-2024, 11:10 AM
steve25's Avatar
steve25 steve25 is offline
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 14,535
Default

The motor has no place for the crankcase pressure to go with no PCV.

Besides that part of a stock system which only works when there is enough vacuum the factory set up had a breather tube off of one valve cover that was plumbed to the air cleaner and that vacuum source would then take over once the PCV no longer worked .

__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #13  
Old 02-13-2024, 11:14 AM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Formulas, my current set up and problem is lower hp and tq than before. 542hp 581tq now against 620hp 601tq.

Total timing is the same at 34 so do you think setting it at 30 will help?

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #14  
Old 02-13-2024, 12:01 PM
Stan Weiss's Avatar
Stan Weiss Stan Weiss is offline
Ultimate Warrior
 
Join Date: Jul 2013
Location: Philadelphia, PA
Posts: 4,990
Default

Quote:
Originally Posted by 461-69bird View Post
Formulas, my current set up and problem is lower hp and tq than before. 542hp 581tq now against 620hp 601tq.

Total timing is the same at 34 so do you think setting it at 30 will help?
Do you have dyno sheets from both engines?

Stan

__________________
Stan Weiss/World Wide Enterprises
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software
http://www.magneticlynx.com/DV
Download FREE 14 Trial IOP / Flow Software
http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php
Pontiac Pump Gas List
http://www.magneticlynx.com/carfor/pont_gas.htm
Using PMD Block and Heads List
http://www.magneticlynx.com/carfor/pont_pmd.htm
  #15  
Old 02-13-2024, 12:28 PM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Steve, so having an open breather on each valve cover wouldn't do the same thing? My issue is at 3000rpm and high vacuum around 12"

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #16  
Old 02-13-2024, 12:33 PM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Stan, they are both in these threads

https://forums.maxperformanceinc.com...d.php?t=802656


https://forums.maxperformanceinc.com...d.php?t=870038

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #17  
Old 02-13-2024, 01:38 PM
Dave Polichena's Avatar
Dave Polichena Dave Polichena is offline
Chief Ponti-yacker
 
Join Date: Mar 2004
Location: Lake Worth FL
Posts: 546
Default

Quote:
Originally Posted by 461-69bird View Post
Thanks Dave, do you think they would help or are needed?
This could help a bunch, the crankcase needs to get vacuum. Your current set up is not allowing enough area to pull from the top, especially with header evac. Your limited real estate up top is your crutch. Fix that and you may get better ring seal too.

__________________
Dave Polichena
  #18  
Old 02-13-2024, 01:41 PM
shaker455's Avatar
shaker455 shaker455 is offline
Ultimate Warrior
 
Join Date: Feb 2002
Location: NH
Posts: 4,470
Default

Hi Rick,
I saw your post and asked Lenny to look as well.
In short he said the brace will not cause pressure.

Before that I was thinking if you use an electric fuel pump and if it was the case with pressure,
You can try using the fuel pump mount on timing cover as a vent, I've seen some pretty tall chimneys people built in the past.
Jeff

__________________
Carburetor building & modification services
Servicing the Pontiac community over 20 years

Last edited by shaker455; 02-13-2024 at 01:58 PM.
  #19  
Old 02-13-2024, 02:23 PM
461-69bird's Avatar
461-69bird 461-69bird is offline
Chief Ponti-yacker
 
Join Date: Apr 2005
Location: England
Posts: 520
Default

Thanks Jeff, I tried messaging Lenny to ask his thoughts, good to know. How would I do the fuel pump mod?

__________________
69 Firebird
472, KRE 85cc, Victor, 850xp, TH400, TSP 9.5" 4800, 3.90 10 bolt, Viking DA rears, QA1 single fronts, 3558lbs. best to date 10.90 @123
  #20  
Old 02-13-2024, 02:55 PM
shaker455's Avatar
shaker455 shaker455 is offline
Ultimate Warrior
 
Join Date: Feb 2002
Location: NH
Posts: 4,470
Default

He is not on here often but I hope he chimes in as he did one of those set ups for his current Gasser.
Hole in block off plate with welded tube or pipe threaded elbow.
On his I think he has a hose up into fender well.
Long time ago I saw a pic of one J-shaped. Tube pretty high with a breather type bird house on top.
I'll look for a pic later today.

__________________
Carburetor building & modification services
Servicing the Pontiac community over 20 years
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 12:04 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