Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Fri Mar 29, 2024 12:37 am

All times are UTC-07:00




Post new topic  Reply to topic  [ 6 posts ] 
Author Message
PostPosted: Fri Aug 23, 2019 8:19 am 
Offline
4 BBL ''Hyper-Pak''

Joined: Thu Sep 08, 2016 3:00 pm
Posts: 41
Location: Chicagoland
Car Model: '69 Coronet, 1980 Volare Wagon
I am running Clifford shorties on a 1980 Slant with a stock intake manifold. Is there any benefit to blocking off the underside of the intake?


Top
   
PostPosted: Fri Aug 23, 2019 9:12 am 
Offline
Supercharged
User avatar

Joined: Sun Nov 03, 2002 9:20 pm
Posts: 13008
Location: Fircrest, WA
Car Model: 76 D100
No. In fact, there is great benefit to adding some kind of provision to heat the bottom of the intake manifold.


Top
   
PostPosted: Fri Aug 23, 2019 9:42 am 
Offline
Supercharged
User avatar

Joined: Thu Jan 27, 2005 8:32 pm
Posts: 7834
Location: Portland-ish
Car Model: Fiat 500e
SpeedBanana1977 wrote:
I am running Clifford shorties on a 1980 Slant with a stock intake manifold. Is there any benefit to blocking off the underside of the intake?


No, but you must block off the EGR port to avoid a vacuum leak. Also, I wouldn't use an unheated intake manifold on a daily driver. The driveability, emissions and engine life will all suffer.

_________________
Joshua


Top
   
PostPosted: Wed Sep 25, 2019 8:25 pm 
Offline
1 BBL (New)

Joined: Sun Mar 05, 2017 8:40 pm
Posts: 1
Location: Nashville, TN
Car Model:
Joshie225 wrote:
No, but you must block off the EGR port to avoid a vacuum leak. Also, I wouldn't use an unheated intake manifold on a daily driver. The driveability, emissions and engine life will all suffer.


First post here. I've currently been researching this page heavily because I have to, at minimum, replace my manifold/intake gasket and I'm curious just how much all of the above would suffer by switching to a header setup? Due to my exhaustive research that headers are the way to go if you don't want to constantly worry about a gasket blow-out and my truck is already registered as an antique vehicle here in Tennessee so I can only drive it intermittently.. It's an 85 D-100 that I acquired 3 years ago. Don't know a ton about it besides it was a one owner. I can tell some modifications have been done (distributor doesn't have a vacuum pot) but I don't know what exactly.

_________________
Just an old farm truck, 225 slant. Retired from the farm, now plays in city traffic.


Top
   
PostPosted: Wed Sep 25, 2019 8:38 pm 
Offline
Supercharged
User avatar

Joined: Thu Jan 27, 2005 8:32 pm
Posts: 7834
Location: Portland-ish
Car Model: Fiat 500e
If your distributor is a Chrysler unit without a vacuum advance it also doesn't have a mechanical advance as the timing was (is) computer controlled. This is original, not aftermarket. Search the board for "Lean Burn" to read all about it. Long story short is that it's almost impossible to maintain any more and many people fit a conventional electronic distributor to trigger a GM HEI module.
viewtopic.php?f=28&t=28732&hilit=hei+discussion

Headers without some kind of intake heat will shorten engine life and make the thing a pain to drive in all but the warmest weather. What's better than headers for a daily driver is a front Dutra manifold and a modified rear manifold. Making the exhaust manifold 2-piece keeps it from breaking into 2+ pieces when the manifolds are over tightened.

Honestly, I would just replace the exhaust manifold and install it correctly if your manifold is cracked. They really aren't that much trouble when they're flat.
https://www.rockauto.com/en/moreinfo.ph ... 85&jsn=952

_________________
Joshua


Top
   
PostPosted: Thu Sep 26, 2019 8:57 am 
Offline
Turbo EFI
User avatar

Joined: Fri Dec 30, 2005 2:49 pm
Posts: 1152
Location: Houston, TX
Car Model:
I agree with Josh; the biggest cause of leaky manifold-to-head gaskets is a warped exhaust manifold. You can have your manifold planed flat by a machine shop, if it isn't cracked (maybe as much as $100, depending on location), or you can buy a new one. I'm still amazed that these are available new.

If you want dual exhaust, the Dutra solution is the most reliable.

_________________
Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 6 posts ] 

All times are UTC-07:00


Who is online

Users browsing this forum: No registered users and 46 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Limited