Hope this is the correct forum... Got an engine vibration problem.

Have a 1986 351w in an e-250 superduty van. Had been having a number of problems, so, decided to make some changes.

Original block and internals unchanged: Changed = Edelbrock 2181 intake, Edelbrock 1406 carb., timing chain and gears from Ford, harmonic balancer from Ford, motor mounts, alternator, fuel pump, battery, water pump, oil pump and screen, starter, MSD ignition, Accel Supercoil, rebiult heads from another '86 351, no emissions or related hardware, no A/C or related hardware, new vacuum hoses, plugs, Bosch 8 mm wires, Hedman Hedders, Dynomax? Raptor mufflers on 2 1/2" true dual exhaust, changed differential fluid with Ford products, tranny changed less than 30,000 miles ago (always check fluid level/color), new filters (all), pcv valve, name brand 10w30, added external transmission radiator (did not re-connect to main radiator). Changed literally every gasket on the engine.

Did compression check before making changes (trying to find out if oil problem was rings, etc.) and after - between 140 and 150 all around. Tops of pistons looked good with heads off, no disfiguration/scoring, etc., no major deposits.

Engine vibrates in park, neutral, any gear or speed (though it does seem to mellow somewhat in park around 2200 rpm). You can see the power steering pump shake (yes it's bolted down tight).

Tried doing a search for engine vibration problems but probably didn't ask correctly 'cause the results really didn't help.

Thanks for your replies, and pardon my ignorance for repeating/posting incorrectly/general stupidity, etc.

Munrow

 

Would like to offer apologies for posting this topic on both 351w, and, Performance and general engine building forums. Promise not to do it again.

Munrow

 

Did you get a 28 oz. harmonic balancer? All 351W engines have 28 oz imbalance and 302 were 28 oz up until 1981 then they changed to 50 oz. I'll bet they gave you a 302/50 oz harmonic balancer.

 

Got the van 7/02 (totaled a crackerbox '98 Dodge, insurance paid for a REAL van). Ran so-so for 98000 miles w/emissions. Catalytic got clogged, removed it and replaced C6 transmission w/local rebuild around 9/03. Think vibration started about April this year. Strange thing is that sometimes it vibrates bad, sometimes not so bad. Was told it was the balancer, changed it, same vibration afterwards.

Didn't remember looking at weights. Compared new Ford part to old and it was an exact match (shape, size, markings, etc.).