Okay, I have this Van that people like to make fun of because they are clueless about it and me. But I recently developed a problem I need to rectify. The engine is a Cologne Built, 4.0L, V-6, OBD-1, EFI powered FoMoCo Like an Iron Duke GM, it's all iron & they last & last. Unfortunately they use Torque To Yield (TTY) head bolts. What I'm learning about TTY's is, that +180 degree tweak after reaching actual torque spec is an arbitrary and capricious maneuver.
I've come to the conclusion a last tweak of a breaker bar makes for uneven torquing. That causes bolt tensil strength to vary & distort within bolt shanks. Anybody who builds or has built engines knows irregular, uneven torque or torque out of sequence causes head gaskets to eventually fail, or So I Have Learned.
Okay here's my deal, I passed 230K on my Van 2 weeks ago as I went to Ft. Jackson, SC. On post I got tied up in traffic and did a lot of Idling. I had poor cooling in nearly 100*F ambiant heat there. Temperature guage never got out out of paremeter, but it did rise about half again where it normally runs, not quite center of gauge quadrant over all. I run a 198F T-Stat as spec'd. I use OEM 13# cap & a brand new Aluminum 3 row HD Radiator. After what seemed to be forever in that traffic jamb, I began to detect a slight miss in the engine.
After clearing the traffic snarl temp qwikly returned to normal range and position. We got on Highways to FLorida. I noticed a stumble as I "breathed" the throttle. If I stabbed it there was no stumble. The stumble turned into a miss at idle, then weak cylinder under a pulling load. We made the trip home. I lost about 5mpg fuel avg'. Engine was not crisp & strong any more. Miss is there at idle. Apparently I pumped out 1.5 Gallons of coolant in about 350 miles. The Van never lost coolant B4. I have no visible leaks in system on inspection. All that info/ diag' = Head gasket to me.
Van requires body be lifted off front frame, or front frame lowered from body to get at powertrain to do engine work I must do. There's no pulling heads off & replacing gaskets in vehicle in this bad boy. My 1st plan was to do that. Then body lifting became apparent.
BUT I have a few options to consider. 1st I have 3 engines, 2 on stands & 1 in the Van with the problem. I do not want to just drop an engine, well maybe drop is the wrong word, Put an engine in there off a stand. Both spares ran when I took them out of Vans they came in. Both are OEM Stock. My thoughts now are to R&R the head gaskets and replace the TTY bolts with standard torquable head bolts from ARP on 1 of the spare engines> I'll use EFI set up off current engine in Van. EFI is pristine, fresh & set up right, coil pack is new, primary wires were replaced 5,000 miles ago along with double platnum plugs.
Anybody got any input on this scheme? Pros or Cons? Anybody here swap the TTY bolts for standard head bolts, or studs on Gen Principles? Objective here is to do it Best
I can. Not cheapest, Not qwikest, Not easiest, BEST. . . . No I'll not install a GM in my Aerostar under any circumstance. With a handle FORDBOY I just can't do something like that.
PS
I'd not change TTY Head Bolts if I had an Alloy Engine or bi-metal construction like Alloy Heads on an Iron Block or vice-a-versa. But Iron on Iron Req's better than TTY Bolts IMHO atleast.
CIAO Y'all
FBp
I've come to the conclusion a last tweak of a breaker bar makes for uneven torquing. That causes bolt tensil strength to vary & distort within bolt shanks. Anybody who builds or has built engines knows irregular, uneven torque or torque out of sequence causes head gaskets to eventually fail, or So I Have Learned.
Okay here's my deal, I passed 230K on my Van 2 weeks ago as I went to Ft. Jackson, SC. On post I got tied up in traffic and did a lot of Idling. I had poor cooling in nearly 100*F ambiant heat there. Temperature guage never got out out of paremeter, but it did rise about half again where it normally runs, not quite center of gauge quadrant over all. I run a 198F T-Stat as spec'd. I use OEM 13# cap & a brand new Aluminum 3 row HD Radiator. After what seemed to be forever in that traffic jamb, I began to detect a slight miss in the engine.
After clearing the traffic snarl temp qwikly returned to normal range and position. We got on Highways to FLorida. I noticed a stumble as I "breathed" the throttle. If I stabbed it there was no stumble. The stumble turned into a miss at idle, then weak cylinder under a pulling load. We made the trip home. I lost about 5mpg fuel avg'. Engine was not crisp & strong any more. Miss is there at idle. Apparently I pumped out 1.5 Gallons of coolant in about 350 miles. The Van never lost coolant B4. I have no visible leaks in system on inspection. All that info/ diag' = Head gasket to me.
Van requires body be lifted off front frame, or front frame lowered from body to get at powertrain to do engine work I must do. There's no pulling heads off & replacing gaskets in vehicle in this bad boy. My 1st plan was to do that. Then body lifting became apparent.
BUT I have a few options to consider. 1st I have 3 engines, 2 on stands & 1 in the Van with the problem. I do not want to just drop an engine, well maybe drop is the wrong word, Put an engine in there off a stand. Both spares ran when I took them out of Vans they came in. Both are OEM Stock. My thoughts now are to R&R the head gaskets and replace the TTY bolts with standard torquable head bolts from ARP on 1 of the spare engines> I'll use EFI set up off current engine in Van. EFI is pristine, fresh & set up right, coil pack is new, primary wires were replaced 5,000 miles ago along with double platnum plugs.
Anybody got any input on this scheme? Pros or Cons? Anybody here swap the TTY bolts for standard head bolts, or studs on Gen Principles? Objective here is to do it Best
I can. Not cheapest, Not qwikest, Not easiest, BEST. . . . No I'll not install a GM in my Aerostar under any circumstance. With a handle FORDBOY I just can't do something like that.
PS
I'd not change TTY Head Bolts if I had an Alloy Engine or bi-metal construction like Alloy Heads on an Iron Block or vice-a-versa. But Iron on Iron Req's better than TTY Bolts IMHO atleast.
CIAO Y'all
FBp