Cost difference when building a 306 vs. 347
- Thread starter 90mustangGT
- Start date
I wasn't really considering C.A.T., just never heard of it. I was wondering how hood they could be when the 4340 Forged unit was about the same price as most companies cast, and cast 3.4" stroke was something around $120.
I did a compression check on the engine. It got suprisingly even numbers with the compression:
1 - 155
2 - 165
3 - 160
4 - 160
5 - 155
6 - 160
7 - 165
8 - 160
The numbers wern't on the digit because the gauge was in 5psi incriments, but that's all averaging 160psi, two down 5psi, two up 5psi. The test was performed at operating temprature, with all plugs removed, throttle closed, about 10 turns to get peak numbers. It took about 2 - 3 turns of the engine to get over 80psi.
I'll do the leakdown check next when my co-worker brings in the tool, he said that will tell me more.
If the engine does well with the leakdown, should I get another block and build that engine? I'd hate to tear down a good motor, it could be put in something else.
I did a compression check on the engine. It got suprisingly even numbers with the compression:
1 - 155
2 - 165
3 - 160
4 - 160
5 - 155
6 - 160
7 - 165
8 - 160
The numbers wern't on the digit because the gauge was in 5psi incriments, but that's all averaging 160psi, two down 5psi, two up 5psi. The test was performed at operating temprature, with all plugs removed, throttle closed, about 10 turns to get peak numbers. It took about 2 - 3 turns of the engine to get over 80psi.
I'll do the leakdown check next when my co-worker brings in the tool, he said that will tell me more.
If the engine does well with the leakdown, should I get another block and build that engine? I'd hate to tear down a good motor, it could be put in something else.
I am kind of in the same boat as you 90. I have a 351w already bored 40 over and fully rebuilt, but I will be faced with using my existing 302 stuff. I just put this combo together a year ago and will be on a serious boder line food stamp budget because of it. I would suggest stroking it. The first time you stomp on it and rip the seat bolts from the floor board or grenade your tranny, it will be well worth it.
Leakdown test results:
Did a leakdown test today using a Snap On Leakdown Tester: Results measured in percentage of leakdown.
Rating are:
00-10 - Excellent
11-20 - Good
21-30 - Acceptable
31-40 - Trouble
My engine:
1 - 32%
2 - 36%
3 - 26%
4 - 30%
5 - 42% :damnit:
6 - 50%
7 - 42%
8 - --% not enought time so I didn't get to it.
Just another excuse to tear it down.
Did a leakdown test today using a Snap On Leakdown Tester: Results measured in percentage of leakdown.
Rating are:
00-10 - Excellent
11-20 - Good
21-30 - Acceptable
31-40 - Trouble
My engine:
1 - 32%
2 - 36%
3 - 26%
4 - 30%
5 - 42% :damnit:
6 - 50%
7 - 42%
8 - --% not enought time so I didn't get to it.
Just another excuse to tear it down.
