TOPICS . TREE-VIEW . SEARCH . LAST: 1 | 3 | 7 DAYS . HELP! . PROFILE . REGISTER . CHAT  

318 engine & 273 exhaust

The Early A-Body Forum » General Discussions » Archive through January 16, 2009 » 318 engine & 273 exhaust users admin

Author Message
Cuda65vpt
Member
Post Number: 20
Registered: 12-2007
Tuesday, September 02, 2008 - 7:42 am   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
does the 318 have extra holes in the head for exhaust mounting that have to be plugged when installing 273 exhaust manifolds? I've replace the gaskets and the driver's side still has a leak. I can feel a hole below the front exhaust port blowing hot exhaust, I can't see it well enough to tell what is going on. I didn't put the car together so I would appreciate any input.
Neilb
Administrator
Post Number: 1177
Registered: 12-2001


Tuesday, September 02, 2008 - 10:09 am   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
Depends on what year of 318. 1970's 318's have these smogger heads with extra little holes under the exhaust ports that led to some smog stuff (I don't know all the terminology). If you're using your older 273 manifolds you need to tap and plug those holes. It's much easier with the engine out of the car!

In this photo you can see the small exhaust holes under the normal exhaust opening.

318

That's what I have in my car, a 318 with 70's heads with the little ports, but a previous owner already had plugged them (except one). My 273 manifolds didn't fit either, I had to grind the head at the back drivers side to get the manifold in there, but now all is well.
'65 Barracuda Formula S
Ottawa, Ontario
http://cuda.enbcom.com
Cuda65vpt
Intermediate Member
Post Number: 22
Registered: 12-2007
Tuesday, September 02, 2008 - 10:31 am   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
That looks like what I envisioned from getting my fingers burned by hot exhaust. Can I brute force and ignorance a self-tapping bolt in there?
Neilb
Administrator
Post Number: 1178
Registered: 12-2001


Tuesday, September 02, 2008 - 2:39 pm   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
I don't know about that, maybe someone else knows? It probably won't hurt to try, or some JB weld. The worst that would happen with JB weld is it will fall out.
'65 Barracuda Formula S
Ottawa, Ontario
http://cuda.enbcom.com
Codfish
Advanced Member
Post Number: 48
Registered: 9-2007
Tuesday, September 02, 2008 - 2:58 pm   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
I'd be afraid that you'd never get the right angle of approach and f**k the hole up forever if you tried B.F. & I , and not sure JB weld would take the heat....always best to do it right!
Neilb
Administrator
Post Number: 1179
Registered: 12-2001


Tuesday, September 02, 2008 - 3:07 pm   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
Ya, I think I agree with Codfish. Do it right. My heads already had the little holes tapped (threaded) but one bolt was missing for some reason. I got a bolt in there with some locktite and cut it off and filed it down, it has never been a problem since. Your hole might already be threaded, in fact maybe they were threaded from the factory? I don't know.....
'65 Barracuda Formula S
Ottawa, Ontario
http://cuda.enbcom.com
Cuda65vpt
Intermediate Member
Post Number: 23
Registered: 12-2007
Tuesday, September 02, 2008 - 9:03 pm   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
Thanks for the responses, I'll pull the manifolds this weekend and inspect the holes for threads. maybe I'll be lucky but given Murphy's latest trends I'm screwed, without threads or lube.
Cuda65vpt
Intermediate Member
Post Number: 26
Registered: 12-2007
Sunday, September 07, 2008 - 10:37 am   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
just as I thought, the holes are smoother than a newborns but. They are 1/4" or slightly smaller, maybe metric. Will a standard 1/4-20 tap be strong enough to cut threads in the head?front port on the drivers side
Codfish
Advanced Member
Post Number: 50
Registered: 9-2007
Sunday, September 07, 2008 - 12:54 pm   Edit PostDelete PostView Post/Check IPMove Post (Moderator/Admin Only)   
Can't be metric! It's a small block mopar!