Carguy3J
Explorer Addict
- Joined
- June 21, 2008
- Messages
- 1,525
- Reaction score
- 3
- City, State
- North East New Jersey
- Year, Model & Trim Level
- '99 4dr. XLT SOHC A4WD
OK, so I have a '93 Ranger, 4.0L-OHV. I have a serious exhaust leak on the drivers side, at the manifold. The problem is, attempting to remove the manifold, to replace the gasket, could very well lead to needing new heads (or at least the left one, I guess- but it would really bother me to do only one side).
Here's why: When I replaced a cracked manifold a few years ago, the top bolt of the middle cylinder snapped. In the process of trying to remove it, that corner of the head, containing the hole for that bolt, cracked and broke off!
I have "rigged" it for the last few years, with JB weld, muffler cement etc, with varying success and durability. Now, the gasket has burnt out at the first cylinder. I started to try to change it a while back, but as soon as I tried to remove one of the other bolts, it didn't "feel" right, and I stopped. I am pretty certain that any attempt to remove the bolts/manifold will result in more snapped off bolts, and possibly more damage to the head.
I REALLY can't afford to buy new heads, not even just one for the left side. However, I have a pair of 98TM heads I removed from a motor I junked. The "post-mortem" showed a a blown head gasket, on the right rear cylinder, with "intrusion" only on the BLOCK side of the gasket. The motor showed signs of being run with poor lubrication, including scored cylinders and wiped bearings, but the heads "look" good.
I know that the 98tm heads are higher compression and have smaller exhaust PORTS. What I need to know is, are they otherwise identical to the 93tm? By that I mean:
1.) In regards to the combustion chamber, are the valves in the same relative location within the chamber, and in relation to all holes/ports,etc...? Are the valves the same size? In other words, could I just "port" the 98tm smaller chamber to larger, to reduce the compression increase, and unshroud the valves, to come close to being indentical to the 93tm chamber shape/size?
2.) I know the exhaust PORT is smaller (98tm), but is the bolt pattern the same? Is the port "centerline" still the same as the older heads (93tm)? What about the runners inside the head, leading up to the port? Are they also smaller, or the same size as the 93tm, and just choked down at the port? Couldn't I just use a 93tm gasket as a template to port match the 98tm head exhaust port to the same size dimensions as the 93tm? Actually, I would do it slightly different, leaving a higher floor vs the 93tm, and concentrate on the roof and long-side side wall.
3.) Is there anything else about the 98tm head that is NOT just plug and play with my '93 4.0l/Ranger? Are the later heads less prone to cracking, such that I can maybe save the time/expense of a pressure test?
Here's why: When I replaced a cracked manifold a few years ago, the top bolt of the middle cylinder snapped. In the process of trying to remove it, that corner of the head, containing the hole for that bolt, cracked and broke off!
I have "rigged" it for the last few years, with JB weld, muffler cement etc, with varying success and durability. Now, the gasket has burnt out at the first cylinder. I started to try to change it a while back, but as soon as I tried to remove one of the other bolts, it didn't "feel" right, and I stopped. I am pretty certain that any attempt to remove the bolts/manifold will result in more snapped off bolts, and possibly more damage to the head.
I REALLY can't afford to buy new heads, not even just one for the left side. However, I have a pair of 98TM heads I removed from a motor I junked. The "post-mortem" showed a a blown head gasket, on the right rear cylinder, with "intrusion" only on the BLOCK side of the gasket. The motor showed signs of being run with poor lubrication, including scored cylinders and wiped bearings, but the heads "look" good.
I know that the 98tm heads are higher compression and have smaller exhaust PORTS. What I need to know is, are they otherwise identical to the 93tm? By that I mean:
1.) In regards to the combustion chamber, are the valves in the same relative location within the chamber, and in relation to all holes/ports,etc...? Are the valves the same size? In other words, could I just "port" the 98tm smaller chamber to larger, to reduce the compression increase, and unshroud the valves, to come close to being indentical to the 93tm chamber shape/size?
2.) I know the exhaust PORT is smaller (98tm), but is the bolt pattern the same? Is the port "centerline" still the same as the older heads (93tm)? What about the runners inside the head, leading up to the port? Are they also smaller, or the same size as the 93tm, and just choked down at the port? Couldn't I just use a 93tm gasket as a template to port match the 98tm head exhaust port to the same size dimensions as the 93tm? Actually, I would do it slightly different, leaving a higher floor vs the 93tm, and concentrate on the roof and long-side side wall.
3.) Is there anything else about the 98tm head that is NOT just plug and play with my '93 4.0l/Ranger? Are the later heads less prone to cracking, such that I can maybe save the time/expense of a pressure test?