TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC V8 Engine Repair and Modifications
  New Posts New Posts RSS Feed - '65 287 Heat Riser Valve
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

'65 287 Heat Riser Valve
 Post Reply Post Reply Page  <12
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
Lucas660 View Drop Down
AMC Addicted
AMC Addicted


Joined: Apr/16/2012
Location: Vic, Australia
Status: Offline
Points: 1344 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Lucas660 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2017 at 6:39am
I have no heat riser valve and dual exhaust with a single muffler on each side. The crossover still gets hot, I have chosen not to block it as the 2 center exhaust points are siamesed. I think there is a reason for the crossover. IIRC Amcenthusiast explains it on his page. Are you using a phenolic? Spacer under the carby?
Back to Top
FunkyStickman View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Apr/16/2015
Location: Louisiana
Status: Offline
Points: 39 		Post Options Post Options   Thanks (0) Thanks(0)   Quote FunkyStickman Quote  Post ReplyReply Direct Link To This Post Posted: Apr/22/2017 at 3:05pm
Originally posted by farna farna wrote:

Make sure the PCV valve isn't stopped up and the tubing is clear. If that's good, then you're getting some blow-by the rings.
I'll check that, but I suspect one of the cylinders has blowby. 

Originally posted by farna farna wrote:

The intake is supposed to get warm under the carb. That shouldn't affect street performance enough to make it sluggish though.

I don't give 2 bits about HP. I just want the thing to be driveable long-distance. So far, since I fixed the exhaust valve, it's helped, but it still vapor locks. Recovery is much faster now, and the engine cools off much quicker, so I know it was a factor.

Originally posted by Lucas660 Lucas660 wrote:

I have no heat riser valve and dual exhaust with a single muffler on each side. The crossover still gets hot, I have chosen not to block it as the 2 center exhaust points are siamesed. I think there is a reason for the crossover. IIRC Amcenthusiast explains it on his page. Are you using a phenolic? Spacer under the carby?

It still has the stock spacer, yes. I still don't know why the damned thing is vapor locking. It's 99% stock... it's gotten better as I've been fixing things, but I can't run it at highway speeds without risking it shutting down on me. This is getting irritating.
Back to Top
Lucas660 View Drop Down
AMC Addicted
AMC Addicted


Joined: Apr/16/2012
Location: Vic, Australia
Status: Offline
Points: 1344 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Lucas660 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/23/2017 at 1:44am
Check the rubber line from the tank sender to the hard line at the back. They are often neglected, a split, pinhole or collapsing hose can cause problems. That being said I always had problems with my old 2bbl carb vapor locking after shutting down on a hot day, especially at altitude. The modern 4bbl has no such problems.
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19679 		Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Apr/24/2017 at 7:30am
There is a fuel filter "sock" on the end of the line inside the tank also. Could it be that you're pulling more fuel than can be delivered? If that sock is partially plugged (or the fuel filter) you could be experiencing starvation, but I think that's a long shot. It should run when you back off the throttle if starvation was the case. Insulate or re-position the fuel line. Today's gas will vaporize much easier than fuel made in the 60s and 70s, that's why it's a problem now but wasn't 30+ years ago.
Frank Swygert
Back to Top
FunkyStickman View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Apr/16/2015
Location: Louisiana
Status: Offline
Points: 39 		Post Options Post Options   Thanks (0) Thanks(0)   Quote FunkyStickman Quote  Post ReplyReply Direct Link To This Post Posted: May/07/2017 at 2:18pm
Believe it or not, I think this is what was happening, in conjunction with the other issues.

We replaced the fuel filter with a clear one, and noticed it was hardly pulling any fuel... not even halfway filling up the filter. What I figured was that the pump was only putting enough fuel in the bowl to cover the jets, and once it got hot, the gas was evaporating faster than the pump could keep up. Which is why it only happened at highway speeds AND when the car was hot.... in fact, more of it was evaporating than it was using. I only got 80 miles out of a 19 gallon tank.

We pulled the filter, blew some compressed air into the line, and HOLY COW the crap that came out of that thing was astounding. It was clogged solid. Did that a few times and it still looked bad, so the car is now at my dad's house and we're dropping the tank and replacing the whole fuel line. (I can also fix the fuel level sender while it's down!)

Not sure if the pump's toast yet, but we won't know until we get the fuel system sorted. That's easy to fix, too.
Back to Top
 Post Reply Post Reply Page  <12
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 7.059 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or