rmchrgr
Skate And Destroy
The #5 intake valve on my W2 headed 340 is ticking pretty loudly. I did a compression test a while ago and the #5 cylinder was the weakest by about 30 psi. Oil pressure is good, 60 lbs at start up, goes to about 40 psi when warm. Lash is set to .026" warm. I had it a little tighter before but backed it off after the tick got louder. I finally did a leak down test the other day after the tick got too loud to ignore and I could hear the air rushing through the intake runner and out the carb. Other than that test and a visual check of the valve gear, the head has to come off to see what the damage is.
Per the previous owner, these W2s are not ported. They have larger intake valves, like 2.05 or something but are as-cast. To me, this has always struck me as curious since most guys who go through the trouble of W2s with the unique valve gear and all are probably going to port them to realize their full potential. Though the engine goes to 7,000 rpm, it's only been a best of 12.0. You have to figure there is some power being left on the table. Most W2 combos I read about are usually at least a second faster in the 1/4 mile, all else being equal. Cam is a MP .557 BTW.
So since at some point the head likely needs to come off, I was thinking rather than spend the coin on fixing these heads, I might call up one of the head guys out there like IMM or Hughes and get the RHS heads I have on my shelf set up. My goal for the car is to get to the mid-11s and I believe the RHS heads can do that no problem.
I have a few intakes to choose from, an LD 340 and an old Holley strip Dominator. I can re-use my existing TTi 1 7/8 step headers since they will bolt up to the RHS heads. Going to the LD 340 might also help to pickup some low end torque if I decide to go that route. The combustion chamber design is also more efficient on the RHS heads as opposed to the ancient open chamber W2s, so perhaps a little gain in that area might help things out as well. I can probably also get away with re-using half my rocker arms, just have to get new, non-offset intakes. Only other thing I think I might need to get is new puhrods.
What do you all think? Should I fix the valve on the W2s and put 'em back on or get the RHS heads set up and see how they do? I'm inclined to do the latter but I'm looking for a some input before I take stuff apart. I've only been driving the car for a little while since finishing it this last spring so being down for repairs so soon is kind of a bummer. It may turn out to be a good thing though.
Thanks for any input.
Per the previous owner, these W2s are not ported. They have larger intake valves, like 2.05 or something but are as-cast. To me, this has always struck me as curious since most guys who go through the trouble of W2s with the unique valve gear and all are probably going to port them to realize their full potential. Though the engine goes to 7,000 rpm, it's only been a best of 12.0. You have to figure there is some power being left on the table. Most W2 combos I read about are usually at least a second faster in the 1/4 mile, all else being equal. Cam is a MP .557 BTW.
So since at some point the head likely needs to come off, I was thinking rather than spend the coin on fixing these heads, I might call up one of the head guys out there like IMM or Hughes and get the RHS heads I have on my shelf set up. My goal for the car is to get to the mid-11s and I believe the RHS heads can do that no problem.
I have a few intakes to choose from, an LD 340 and an old Holley strip Dominator. I can re-use my existing TTi 1 7/8 step headers since they will bolt up to the RHS heads. Going to the LD 340 might also help to pickup some low end torque if I decide to go that route. The combustion chamber design is also more efficient on the RHS heads as opposed to the ancient open chamber W2s, so perhaps a little gain in that area might help things out as well. I can probably also get away with re-using half my rocker arms, just have to get new, non-offset intakes. Only other thing I think I might need to get is new puhrods.
What do you all think? Should I fix the valve on the W2s and put 'em back on or get the RHS heads set up and see how they do? I'm inclined to do the latter but I'm looking for a some input before I take stuff apart. I've only been driving the car for a little while since finishing it this last spring so being down for repairs so soon is kind of a bummer. It may turn out to be a good thing though.
Thanks for any input.
