Hi - I have 250ci(4.1) that has been transplanted into a 1959 Willys wagon but that's beside the point. The engine runs fine except for some serious vibration upon acceleration, revving, etc. I am pretty certain it boils down crankshaft balance. I am yet to pull the engine or drop the transmission but I would appreciate any info for what flywheel /damper combination I would need for my present setup of three speed manual transmission. I don't know if the engine came from a manual or automatic transmission car. If it was automatic it's assumed that the flex plate was replaced with a flywheel but I would like to know which flywheel it should be before I start. Also, the damper is original to the engine but I don't know if the damper (about 6 3/4" two grove pulley no obvious balancing) is common to both manual or automatic transmission applications? And I'm sure the vibration is not coming from anything past the output of the engine, also have replaced motor mounts, damper rebuild, etc. Any Info greatly appreciated. Thanks.
250ci straight 6 Info?
- Thread starter edcom
- Start date
Also make sure that there is a pilot bushing in the crank and it is the right size for support of the input shaft.
If the flywheel is not Neutral it can most likely be made one, at a shop that does balancing.
If the flywheel is not Neutral it can most likely be made one, at a shop that does balancing.
Thanks for that I wasn't sure because some retail sites are selling "unbalanced"? So does that imply that it will fit but needs be neutral balanced before installing? Thanks
Thanks for that, will do. So the flywheel that's on the car now is obviously the right size and tooth count since the engine starts and runs fine - except for the vibration, so does that mean that it is the correct flywheel - if neutral balanced, or does weight or any other factor matter? I ask because I doubt that I will be able to find the correct number for the engine?
good call on Pilot bushing check, many specifics could cause the engine seeming imbalance, if determined to definitely be a 'balance' issue, the 250 :
250 uses 'SBF' ( V8 289/302/351W ) Flywheel , Clutch , BellHouse, Starter.
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The 250 SIX 'SBF' Flywheel used is 157T 'Neutral/Internal Balance" ( most SBF V8's use 'Weighted/External' 157T FW, some use the same neutral balance FW as six). same clutches etc can be used as most V8 SBF's applications .
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250 FW's aka SBF 157T 'Neutral/Internal Balanced' readily available, many aftermarket versions use bolt-on 50/28 Ounce weights that can be deleted for the 'Neutral Balance' 250.
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Front balancer is harmonic balancer not crank balancer on 250. Matching Pulleys a common headache with swaps.
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presuming - Toploader (3.03) 3 speed, the old style 'long-frame' clutches were vulnerable to imbalances, modern 'diaphragm' types including HiPo V8 types can be used . Diaphragms are usually smoother with less pedal effort.
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I used a Column shift Toploader 3 speed (Maverick) in a '61 Comet with the 250 - awesome driving combo later upgraded to OD T5 with simple 'SBF-BH adapter plate' .
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have fun
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250 uses 'SBF' ( V8 289/302/351W ) Flywheel , Clutch , BellHouse, Starter.
.
The 250 SIX 'SBF' Flywheel used is 157T 'Neutral/Internal Balance" ( most SBF V8's use 'Weighted/External' 157T FW, some use the same neutral balance FW as six). same clutches etc can be used as most V8 SBF's applications .
.
250 FW's aka SBF 157T 'Neutral/Internal Balanced' readily available, many aftermarket versions use bolt-on 50/28 Ounce weights that can be deleted for the 'Neutral Balance' 250.
..
Front balancer is harmonic balancer not crank balancer on 250. Matching Pulleys a common headache with swaps.
.
presuming - Toploader (3.03) 3 speed, the old style 'long-frame' clutches were vulnerable to imbalances, modern 'diaphragm' types including HiPo V8 types can be used . Diaphragms are usually smoother with less pedal effort.
.
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I used a Column shift Toploader 3 speed (Maverick) in a '61 Comet with the 250 - awesome driving combo later upgraded to OD T5 with simple 'SBF-BH adapter plate' .
. .
.
. ..
.
have fun
.
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It's 4wd and I read in a Willys forum that the 250 was a popular choice because it could be installed without having to reposition the rest of the drivetrain, although it is a pretty tight fit front to back, I had to cut a hole in the firewall to get at the back bolts when removing the head. Will send pics as soon as I figure out how, I don't see a button for attachments.
edcom- welcome! Nice combo, 250 in the Willis.
There's a minimum number of posts required before pics are allowed. The moderators had to set it up that way a while back due to scammers. Not sure how many posts, but not bad. Won't be long. Looking forward to seeing your ride!
The front damper is very unlikely to be cause of the imbalance.
If the clutch is not correctly installed that can cause vibration. It will also cause chatter (bad!) when engaging the clutch. Does the clutch chatter excessively?
PB covered it well. Again if you have a SBF V8 flywheel it will fit but they have weights or holes drilled to make it heavier in places that work to balance an externally balanced V8, your 250 is naturally balanced by design and need no weights to balance it. You may have other problems. May have to pull it apart to find out what is what.
"...may have other problems." Yeah, that's the sticky part. But that's the plan. Thanks for the reinforcement.
It's not as pretty as a Mustang but it has own kind of beauty - and it can go through 8" of snow at 45mph!
Attachments
You may try pulling the starter and look for weight or a fair amount of deep balance holes. Keep turning the flywheel so you cover it all. Take pics, This may not for sure rule out it is imbalanced but if the weights or holes are there well then you know.
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