BBC 454 Heads / Gaskets question - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-03-2004, 06:50 PM
rakundig's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Japan
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
BBC 454 Heads / Gaskets question

I have a 454 Mark IV engine from a 70-75 vette.

About a year ago I replaced head gaskets but I am having a heating problem and I am thinking I may have installed the gaskets improperly.

I ordered a new felpro 1017-2 head gasket (same as I put in before) and I have been looking at it and a picture of the block of a Mark IV 454. The picture brings one big thing to mind.

On the top of the gasket there are small holes that are just over 1/8" in diameter. Looking at the picture of the block the holes they line up with appear to be about 1" in diameter.

The gasket has a built in "seal" around the holes that is just over 1" in diameter.

Am I supposed to cut those holes to fit the size of the holes in the block/heads? Or is that tiny little hole supposed to be that size and leave it that way?

I am attaching a picture with the holes I am talking about circled in red. The holes on the bottom (circled in blue) are the same size on teh gasket and the block.

Thanks
Rick
Attached Thumbnails
Click image for larger version

Name:	454_block.jpg
Views:	144
Size:	72.8 KB
ID:	1178  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-03-2004, 09:01 PM
rakundig's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Japan
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I noticed that people are reading this post but no replys yet.

If I need to provide further information please say so. Maybe I have not been clear enough.

Thanks
Rick
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-03-2004, 09:11 PM
KA67_72's Avatar
Member
 
Last photo:
Join Date: Jan 2003
Location: Knoxville, Tn
Posts: 308
Wiki Edits: 0

Thanks: 1
Thanked 2 Times in 2 Posts
What's the compression ratio?
What kind of octane fuel do they sell over there?
I'm assuming you're still in Japan. Is the fuel gas, alcohol, or some blend of the two?

Kevin
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-03-2004, 09:39 PM
NorthStar's Avatar
Member
 
Last photo:
Join Date: Feb 2003
Location: Minnesota
Age: 50
Posts: 847
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Leave the gasket as is. The holes on block are made that big so sand from casting mold can be flushed out after its made.

If you were to make holes in gasket huge then you would really have cooling problems. Coolant would bypass the back of block and back cylinders would run way too hot.

Think about how water enters the block, flows past all the cylinders then is routed up through back of cylinder head and flows forward through the head to thermostat passage.
The little holes in gasket are meant to prevent steam pockets from forming.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-04-2004, 12:19 AM
rakundig's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Japan
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ok, I thought that I should leave them but I wasn't sure.

I am trying to figure out how to fix an overheating problem and head gaskets is my next step (if I have to).

I overheat sitting idle, 4 core griffin rad with shroud and 15" solid fan, no clutch. It blows enough air so that you can feel it at the windsheild with the hood up so I think I have good airflow. You can feel it pretty good at the front of the radiator getting sucked in. If you hold a cigarette in front of the grill the smoke gets sucked in so I think I have pretty good airflow. The fan doesn't cover as much radiator as I would like but I think i will work on that as I can. I will need to move the radiator around in the engine compartment to get a larger one to fit the shroud.

I am using either 87 or 94 octane fuel, depending on if I buy on base or at a japanese gas station. It is not alcohol mixed.

Would an alcohol mix help cool me off? Could my gas cause overheating. I think I heard higher octane burns "cooler".

I don't know my compression ratio but I would guess it is around 10:1. Maybe slighly under. It can run on pump gas.

Thanks
Rick

before I change head gaskets I am going to do a few tests.

Compression checks look good (already did those)
Don't see water in oil or oil in water

I have ordered a test kit to see if there is exhaust fumes in the radiator indicating a microfracture in the head gasket allowing combustion gasses into the rad. If that is the case then off the heads come.

Basically i just wish the darn thing would quit overheating.

In 40 degree weather she runs up slowly to 160 degrees (I put in a new 160 thermostat last week, had 180) then stays there for a good 15 minutes.

Then she will SSLLOOOWWWLLLY start to climb. In the next 5-10 min she will be at about 190-200, she will keep climbing.

I sat in her and gave her gas to 2000 RPM in park and the temp gauge quit climbing for the most part. It still seemed to climb but it was so slow that you really had to pay attention.

Driving around in 40 degree weather also seems to stop the climbing (10 mph) but she won't cool down any. Once I stop she climbs again.

What I am trying to figure out is if this is just the way she is or if something is wrong. (It is a 70-75 vette 454 after all)

I know I can run her up at 210 with no problems but I am afraid to go over that. I have a couple of times in the past, almost 250 once when I wasn't paying attention (this is before the shroud/fan/radiator swap)

I haven't let her run up since then.

Any ideas about if I am really overheating or just running normal or suggestions are always welcome.

Thanks
Rick

Last edited by rakundig; 02-04-2004 at 12:19 AM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-04-2004, 12:44 AM
troy-curt's Avatar
Shop Owner And Troll Hunter
 

Last journal entry: Detailing Eng. Compartment
Last photo:
Join Date: Apr 2003
Location: Prairie Grove Ar.
Age: 75
Posts: 2,646
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Check the sending unit and the gauge, are they matched up or just something you put on that looked right? Sending units do go bad. Is the fan in the right position in the shroud? You should be running a clutch fan, probably a 7 bladed one.

Do you have to add any water?

Those small holes in the head gasket are there to restrict the flow for cooling purposes.

Troy

__________________
If you don't make mistakes. your not doing anything.

69 ss rs full custom camaro 98 ISCA grandchampion
69 ss rs bb camaro wifes driver
66 Elcamino 350/all dz parts,ac,windows,loaded,my driver
69 ss chevelle bb conv.fresh frame off
26 T sedan street rod
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-04-2004, 04:48 PM
rakundig's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Japan
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I am using a matched sending unit and guage. Brand new electric.

I was using a matched mechanical gauge but was worried it was not accurate so I got another one (the electrical) and it shows same readings

I am full of water and am using an expansion tank

I do have a clutch fan but I am not sure I will be able to fit it in the shroud. It is very large, it does pull alot of air and works better than the 15" no clutch but it's size is a problem, it gives me just millimeters clearance between the blades and the hood.

The fan I have is not centered in teh shroud. I am going to have to move the radiator around to get it centered.

The 454 is just damn big.

Thanks
Rick
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-04-2004, 07:55 PM
GTO 1965's Avatar
Member
 
Last photo:
Join Date: Jan 2004
Location: Mo.
Age: 63
Posts: 70
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
does the shroud go all the way to each side of the radiator and all the way to the top and bottom is it up against the radiator tight, are the fan tips within an inch of the shroud all the way around if not the fan is pulling most of the air between it and the shroud, does the car have a/c if so make sure the condenser is not plugged with bugs and road debis. Hope this helps!
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-04-2004, 08:43 PM
rifraf's Avatar
Member
 
Join Date: Dec 2003
Location: washington
Posts: 576
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I bought a 1 ton gmc 454 a couple years back,the poor guy spent a ton of money trying to get it to cool down,he gave up and sold it to me cheap,it had new everything. To make a short story long,the new water pump he was sold had the impeller for the V belt,my point is that they appear identical and there are two different rotations,got the right one?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-04-2004, 11:03 PM
rakundig's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Japan
Posts: 80
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally posted by GTO 1965
does the shroud go all the way to each side of the radiator and all the way to the top and bottom is it up against the radiator tight, are the fan tips within an inch of the shroud all the way around if not the fan is pulling most of the air between it and the shroud, does the car have a/c if so make sure the condenser is not plugged with bugs and road debis. Hope this helps!
I need to work on shroud/fan clearance. The shroud is 18" in Dia and the fan is only 15" and it is slighly offset leaving just over an inch on two sides and under a half in on the othe two sides. I am going to have to move the radiator to get it to center.

The shroud is perfect, fits exactly to the radiator, tight, covers all but a few millimeters of the core.

no ac

Quote:
Originally posted by rifraf
I bought a 1 ton gmc 454 a couple years back,the poor guy spent a ton of money trying to get it to cool down,he gave up and sold it to me cheap,it had new everything. To make a short story long,the new water pump he was sold had the impeller for the V belt,my point is that they appear identical and there are two different rotations,got the right one?
Not sure what you mean but I have two long waterpumps and I have tried them both. I can see flow in the radiator so I know water is moving.

They are V belt pullies but I couldn't say about the impeller. One of the pumps I got directly off a vette and my engine is a vette engine.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-05-2004, 06:36 AM
rifraf's Avatar
Member
 
Join Date: Dec 2003
Location: washington
Posts: 576
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well,my truck uses the same long style you use. Many of the serpentine belt motors wrap the belt in a way that turns the pump the opposite direction,they run off the back side of the belt,to make this work,they changed the shape of the blade inside,it will still move the water but not near as well as it is supposed to. You cant tell appearance wise from the exterior.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 01:33 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.