Hi guys i just pulled the A15 head off and tryed to match it with the info from teck section but cant? My head is a oval port head with the only numbers on it (under valve tran) are 109 on one end and 168H on the other nothing else. the vavles are E 30mm and the IN 37mm the other thing that puts me off is the water holes were the inlet manafold goes are only two 3mm holes on one side and one on the other? every pic ive seen in here looks like its about 10-12mm hole is this a standard head or not and should i drill the water holes out or leave them alone. it also has the kidney shape chambers thanks guys
Hello people some thing differnt for the pros. I have a 12ft jet boat with a A12 in it which just died so i got a A15 can you tell me what would be the best thing to do to get the most hp out of it (now for the good bit?) WITH OUT going over 5500 rpm MAX. The jet pump cant run more than that. thanks for the help.