Engine Temp on HP engine
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
The easy step would be to try to richen the secondaries. Sounds like it's going lean.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Heads were port and polished some, blended and 5 way value job. Flow test after work was done and I believe I remember him saying 254 he was able to get them to flow to.
Only spark knocks when secondary's open up and rpms start to climb over the 3900 to 4000 range. Timing is 34 at 300-3500 rpm and mech only but I did try the vaccum advance also but same thing. I've even retart timing back a little at a time back to 30% but same.
Only spark knocks when secondary's open up and rpms start to climb over the 3900 to 4000 range. Timing is 34 at 300-3500 rpm and mech only but I did try the vaccum advance also but same thing. I've even retart timing back a little at a time back to 30% but same.
You are experiencing problems above 3500 rpm when you go to Wide Open Throttle. I would tend to say that you are having lean popping ... Not detonation.
Just a guess. You are having no fuel to the secondaries or limited. another guess is that on the back of the carb or manifold that you have a 3/8ths vacuum line to the vac brakes and headlights that is open or leaking.
Ram horns would run rich compared to a header setup because of restriction
Thread Starter
Instructor
Joined: Apr 2009
Posts: 175
Likes: 12
From: Jacksonville NC
Spark knock proble solved
Tune was probably optimized to be used with headers putting in a colder plug lost me power...every motor has different needs though.
If it were me Id get an 02 sensor (check AEM at summit for example) in your collector and see what the car is doing;h opefully you can tune around it id think you could
Or if you dont mind the funds get a better radiator/fan combo and bring your running and air inlet temps down.
If you got a cool stat get a better fan (flame suit on)and put the clutch deal off to the side I hate those things
Not saying that is THE solution but you wont regret it for sure. Bigger motor/power means more heat needs more cooling capacity.
Sounds like youre happy with overall power shame someone talked you into dumping all that money into old iron heads.
Keep us posted
If it were me Id get an 02 sensor (check AEM at summit for example) in your collector and see what the car is doing;h opefully you can tune around it id think you could
Or if you dont mind the funds get a better radiator/fan combo and bring your running and air inlet temps down.
If you got a cool stat get a better fan (flame suit on)and put the clutch deal off to the side I hate those things
Not saying that is THE solution but you wont regret it for sure. Bigger motor/power means more heat needs more cooling capacity.
Sounds like youre happy with overall power shame someone talked you into dumping all that money into old iron heads.
Keep us posted
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Glad you were willing to try something new vs struggling with the current configuration forcing it to kinda work. Good Job!
