When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi thanks for that makes sense.i will get a new inlet gasket . But what is an open heat riser. This is the first v8 engine I have had so some of the things mentioned I have never encountered. Many thanks ivor
Hi thanks for that makes sense.i will get a new inlet gasket . But what is an open heat riser. This is the first v8 engine I have had so some of the things mentioned I have never encountered. Many thanks ivor
In the photo below you will see a hole in the red circle.......this hole goes directly to the exhaust port believe it or not and is where the heat comes from.....this is an "open" heat riser. There is an accompanying hole on the intake where it bolts down. The 1204 gasket blocks this hole with a thin piece of stainless steel.
Jebby
Last edited by Jebbysan; Mar 26, 2020 at 01:54 PM.
On the passenger exhaust manifold there is a heat riser valve that blocks and forces exhaust through that hole at cold start up.....unless you removed it during your install.
The first pic is the valve...the second is the spacer offered to delete this.....you can wire, weld or remove the plate so it is open.....but the clean fix is the spacer.
If this valve sticks closed....it will force all of the exhaust through the middle of the intake to the other side....creating scalding heat.....this miserable thing was the cause of many woes in the 70's.......it could actually destroy the engine over a period of time.
Jebby
Last edited by Jebbysan; Mar 26, 2020 at 01:54 PM.
Hi Jebbysan. My engine does not have a heat riser fitted which makes me think the last owner had the inlet gasket changed as well . I am trying to contact him . If I can’t I have ordered a new one anyway . Thanks for your help ivor
Hi Jebbysan. My engine does not have a heat riser fitted which makes me think the last owner had the inlet gasket changed as well . I am trying to contact him . If I can’t I have ordered a new one anyway . Thanks for your help ivor
Well, if it gets super hot in that area of the intake, super fast....then it is still open.
Going back.....are you sure you have a clear supply of fuel to the pump?
Hi Jebbysan I have a clear fuel filter fitted it is always 3/4 full when running good and the same when running rough . My only thought is if the inlet gasket is not the modified type that could be the problem . It’s very frustrating I have been right through the fuel system and the ignition . I have to keep calm and carry . Many thanks ivor.
Hi Jebbysan I have a clear fuel filter fitted it is always 3/4 full when running good and the same when running rough . My only thought is if the inlet gasket is not the modified type that could be the problem . It’s very frustrating I have been right through the fuel system and the ignition . I have to keep calm and carry . Many thanks ivor.
Ok good....if you pull the intake you should install a 2701 Performer EPS that your 600 Holley carb will bolt right to.....it will delete the EGR...you can block the heat riser and pick up a few ponies in the process....not sure how difficult it would be for you to get one over there.....but it would eliminate the need to find a Q-Jet carb....and would run very well once tuned.
Also....remove the adapter plate and take a photo of the bare intake....if you have the “hot port” intake....it is very easy to use the wrong carb base gasket....especially with an adapter.
Hi thanks to everyone who tried to help me with my problem. I have no found out why my car kept running. After the engine swop on driving home the car did 40 mile then shutdown restarted then 20 mile in the end 500 yards . First thought lack of fuel but fuel always in the visible fuel filter . When engine stopped would still inject fuel into inlet . So then ignition replaced all ignition components. Swapped ballast resisted coil
for 12 v sports coil . Removed all filters from radio car wiring. Still no joy .back to inlet manifold fitted new inlet gasket with stainless steel inserts . No better . Then thought drop the fuel tank . HERE IS THE PROBLEM. Kinked rubber fuel pipe . So engine would run for a short time the pump would suck the kinked pipe shut .then at rest would leak through a bit more fuel . What a task this has been . So thanks again ivor
