Triumph Sports Cars

Richard, that's about what just the manifold would have been worth had I been able to buy just that part. The carbs with basically 9ll jetting and 26mm chokes worked well on the bone stock 231. I have taken the chokes out to 36mm and changed the idle jets somewhat and the engine runs real well except with a hot start (over 95*) problem. I found out that the screens on the velo stacks aren't for catching bugs but are flame arrestors. One backfire inside the air cleaners without the screens tells that tale. I do believe that EFI would solve the hot start problem but the required electronics and the learning curve is a little more than I really want to go through. Attached photo is engine compartment with air cleaners and vacuum brake assist. I have yet to install a coolant pump to circulate water from the engine through the radiator after shutdown tied in with the coolant fan. That will happen sometime this winter. The best of luck with your project.

Greg

Some street bikes might have usable injected throttle bodies.

Jim

Greg, I have MegaSquirt in my Alpine and I must say that starting a heat soaked engine and getting it to run decently is a tough nut to crack. I have not been able to solve the problem. It starts okay, runs (barely) for a minute or so. An issue is that you can only sort things out while it is heat soaked and you are parked in a shopping center lot.

The EFI learning curve is steep, but doable, especially if you are computer literate. I am not, so I lean heavily on my son for computer issues. Without him, I would be dead in the water, not even able to load the firmware. But the actual tuning process not that bad. That is good, because he knows NOTHING about tuning. Together, we do okay.

Bill

Bill, Thanks for the insight. You are right in the fact that it only wants to do really bad things when you are in the Walmart lot and a lot of people standing around. I'm confused. Does the megasquirt still not help the hot start? After I found the gas line running close to the exhaust I thought that I had solved the problem so I removed the heat soak plate between the carbs and manifold. Everything was fine until the air temp went above 90*. The plate went back in and now am considering non-conducting bushings for the mounting bolts. My fuel pump is in the engine compartment also and am going to move it to the rear of the car. Keeping the fuel cool seems to be the mission here so will probably insulate the gas lines that are subjected to heat in the engine compartment also. The problem now is that the hot weather is over and it will be next summer to find out if any improvements were made. I was watching some You Tube vids with vintage race cars and weber carbs and noticed that on start up they all put out a rich exhaust cloud so some of it might just be putting up with the system. I have always been able to get the engine started , its just when it is hot it takes a little longer and of course the blue cloud. There is the one time when the back fire started the float bowls on fire but it was really hot (105*). I have since put the screens back on and although it has backfired, I haven't had a fire but I still flinch when it backfires. There is a definite start-up procedure to the beast, hot or cold.

Greg

Very cool indeed Greg.

Greg, the engine starts fine when heat soaked. It just does not want to do anything until temps A) come down, which would mean the air temperature compensation curve is wrong, or B) the air temp seen in the area of the air temp sensor is the same as the temp seen at the intake valves, don't have any idea how to fight that. Don't know which choice is correct. Maybe a little of both. Fortunately, we do not have much of that kind of temperatures to deal with. Maybe one or two times in a normal year.

A real advange of the EFI is the return fuel system automatically purges, so vapor lock is not a problem. However, the newer cars use a "dead end" system and regulate fuel pressure with fuel pump speed. Guys that use it with MegaSquirt report it is a vapor lock headache.

Bill

Bill, I run my cooling fan after shut down. I have the same condition you describe and after the coolant makes one pass through the engine things calm down. I believe there is a little bit of thermo siphon going on with the fan cooling the coolant that is in the radiator core after shut down. I have a electric coolant pump from a VW that I am going to pull coolant out of the engine at the thermostat area and dump it into the radiator tank hoping that it will pull hot coolant from the engine and circulate it through the radiator and back to the engine after shut down along with the fan. I'm just hoping that it won't short circuit. Where I put the hose on the cross flow tank is probably going to be critical to some degree. Vapor lock isn't a problem with my Webers but flooding is caused by the fuel percolating in the float bowls at least that is what it appears to me. As Donnie Weinmister used to say "I'm not sure I understand everything I know about this thing."

Greg