Need a 351 Cleveland expert

[concrete-steve 10]

A buddy of mine has a 1970 fastback with a 351C in it and the engine has a shake at around 1700 rpm and the number 3 plug seems to not fire or at least not fire well. Been frustrating for all involved (3 mechanics, pretty good on Fords). The heads have been redone (they are the smaller port heads), new distributor, wires, cap, rotor. New carb was put on, compression and leak down on motor came up good. The engine has a cam, don't know the specs. and the initial timing is advanced considerably (22 degrees), but this is where the engine seems most happy.....but still a dog compared to where it should be. When the motor is running you can remove the plug wires one at a time and notice a difference in the rpm, #3 makes no change when you remove it.....We are all at wits end....Anyone have any clues on this?

[concrete-steve 10]

A buddy of mine has a 1970 fastback with a 351C in it and the engine has a shake at around 1700 rpm and the number 3 plug seems to not fire or at least not fire well. Been frustrating for all involved (3 mechanics, pretty good on Fords). The heads have been redone (they are the smaller port heads), new distributor, wires, cap, rotor. New carb was put on, compression and leak down on motor came up good. The engine has a cam, don't know the specs. and the initial timing is advanced considerably (22 degrees), but this is where the engine seems most happy.....but still a dog compared to where it should be. When the motor is running you can remove the plug wires one at a time and notice a difference in the rpm, #3 makes no change when you remove it.....We are all at wits end....Anyone have any clues on this?

[Grabber70Mach 107]

Might want to look around here.....

 

http://www.network54.com/Index/102147

[Grabber70Mach 107]

Might want to look around here.....

 

http://www.network54.com/Index/102147

[paulb 112]

Hi,had a similar problem years back on a customer car,he had the motor recoe'd,after that it had a miss around 1000rpm on,on compression testing all came up well,to cut a long story short,the heads were machined down far enough so that when the cam lobe was on the base it kept the valve open just enough for it to loose compression but was fine on starter turn over with comp guage,fix was to fit a shim under the rocker pedestals problem fixed

[paulb 112]

Hi,had a similar problem years back on a customer car,he had the motor recoe'd,after that it had a miss around 1000rpm on,on compression testing all came up well,to cut a long story short,the heads were machined down far enough so that when the cam lobe was on the base it kept the valve open just enough for it to loose compression but was fine on starter turn over with comp guage,fix was to fit a shim under the rocker pedestals problem fixed

[Fordrevhead 29]

Not to dis any mechanics abilities, but is the Distributor off 180? Sanity check by doing a static timing ignoring the harmonic and pointer. Set to power stroke #1 turn key on, rotate distributor until spark... Betting you cant. Since youve checked everything else next is cam related as stated.

[Fordrevhead 29]

Not to dis any mechanics abilities, but is the Distributor off 180? Sanity check by doing a static timing ignoring the harmonic and pointer. Set to power stroke #1 turn key on, rotate distributor until spark... Betting you cant. Since youve checked everything else next is cam related as stated.

[Lemon Owner 11]

Hi,had a similar problem years back on a customer car,he had the motor recoe'd,after that it had a miss around 1000rpm on,on compression testing all came up well,to cut a long story short,the heads were machined down far enough so that when the cam lobe was on the base it kept the valve open just enough for it to loose compression but was fine on starter turn over with comp guage,fix was to fit a shim under the rocker pedestals problem fixed

 

I am inclined to agree with this. Because the rockers are non adjustable it can cause valve riding issues which I have been having with my freshly rebuilt 351 windsor. I had to replace my rockers as they were worn out and making them do strange things that no ammount of adjustment could fix.

[Lemon Owner 11]

Hi,had a similar problem years back on a customer car,he had the motor recoe'd,after that it had a miss around 1000rpm on,on compression testing all came up well,to cut a long story short,the heads were machined down far enough so that when the cam lobe was on the base it kept the valve open just enough for it to loose compression but was fine on starter turn over with comp guage,fix was to fit a shim under the rocker pedestals problem fixed

 

I am inclined to agree with this. Because the rockers are non adjustable it can cause valve riding issues which I have been having with my freshly rebuilt 351 windsor. I had to replace my rockers as they were worn out and making them do strange things that no ammount of adjustment could fix.

[concrete-steve 10]

Thanks for the input, will double check the distributor for 180. Done so many things can't say for sure this was checked....you know how that goes. We will check the rockers, this may be something, but would think the leakdown would have shown this. All cylinders were in the 12-20% range. Maybe there is some kind of "bounce" at a higher rpm? Thanks for the input, every comment helps!

Edited February 25, 2012 by concrete-steve

[concrete-steve 10]

Thanks for the input, will double check the distributor for 180. Done so many things can't say for sure this was checked....you know how that goes. We will check the rockers, this may be something, but would think the leakdown would have shown this. All cylinders were in the 12-20% range. Maybe there is some kind of "bounce" at a higher rpm? Thanks for the input, every comment helps!

Edited February 25, 2012 by concrete-steve

[Lemon Owner 11]

What it was doing was as I said strange. The only way I could get the engine to settle was to adjust them so they ticked slightly. I first had to make them adjustable to get the engine to idle in gear at all. When I replaced the rockers I tightened them until until I could feel the rod go slightly tighter. Then another quarter turn in and it ran way better than ever before. I think just because the cam was slightly larger and the old rockers were worn into their old groove and didn't like the change. To look at them and feel them you would not have thought them a problem. But the engine just would no run right with them. Incidently I did a compression test and it turned up every cylinder within 10psi despite the valves riding when it was running. Like I said weird.

[Lemon Owner 11]

What it was doing was as I said strange. The only way I could get the engine to settle was to adjust them so they ticked slightly. I first had to make them adjustable to get the engine to idle in gear at all. When I replaced the rockers I tightened them until until I could feel the rod go slightly tighter. Then another quarter turn in and it ran way better than ever before. I think just because the cam was slightly larger and the old rockers were worn into their old groove and didn't like the change. To look at them and feel them you would not have thought them a problem. But the engine just would no run right with them. Incidently I did a compression test and it turned up every cylinder within 10psi despite the valves riding when it was running. Like I said weird.

[concrete-steve 10]

Well, the shims were installed last night and the engine ran better, but lots of ticking. Seems we are going in the right direction, just need to fine tune the whole mess. Thanks for all the input.

[Lemon Owner 11]

Sounds like the same BS I went through. Drove me nuts for a month trying to figure it out. But finally it is finished and seems to be fine. Keep us posted, it sounds like an interesting one.

[buening 63]

I'd recommend sticking a dial indicator on the #3 cylinder valve springs to measure the lift (crank over by hand), and then compare to other known working cylinders. Wiped cam lobe or odd/wrong pushrod. A leakdown test would definitely confirm if the valve was not closing fully, so I'd venture a guess its not an open cylinder. However, did you pull the plug wire and crank it over to confirm that cylinder is getting spark? If so, after running the motor a bit did you pull that plug and see if it was wet from fuel?

[LoneWolf2U 136]

Well, the shims were installed last night and the engine ran better, but lots of ticking. Seems we are going in the right direction, just need to fine tune the whole mess. Thanks for all the input.

 

Stock headed C has positive stop rockers, Which means no adjustment for lifter preloading.

You will have to get an adjustable pushrod to determine proper pushrod lenght to have preload on lifters.

Any mill work to block or heads will change the lifter preload causing poor performance.

[Lemon Owner 11]

Stock headed C has positive stop rockers, Which means no adjustment for lifter preloading.

You will have to get an adjustable pushrod to determine proper pushrod lenght to have preload on lifters.

Any mill work to block or heads will change the lifter preload causing poor performance.

 

Spot on. My block and heads were shaved slightly. That is partly why I had to make mine adjustable. Unfortunately it still acted up no matter how I adjusted those bastards until I replaced the rockers. Now all is well. I don't think any would have suspected the rockers and I'm sure no one believes they were the problem, even me. lol

[Lemon Owner 11]

Any update on this? I am very interested to know how it all went as I have a clevo to rebuild soon too.

[LoneWolf2U 136]

Any update on this? I am very interested to know how it all went as I have a clevo to rebuild soon too.

 

May I suggest that you rework the heads over for Studs and guideplates.

You will still need to use an adjustable pushrod to get the proper lenght, But it makes valve adjusting much easier.

[Powershift 19]

A bit off the subject, but what is a good running Cleveland worth?

 

I'll be pulling my Mach's healthy Cleveland, and Top Loader 4 speed, to swap in a 408w/5 speed combo. The motor will be complete, from carb to oil pan.

[LoneWolf2U 136]

Not trying to be a smarta$$ about it but, Whatever someone is willing to pay for it.

I have watched 351C listed from $800-5K not sell.

 

I picked up mine with a toploader for $500.00 sitting on a garage floor complete. I hooked a battery to it and filled the carb bowels with fresh fuel and it fired up. So I bought it.

 

Got it home and opened it up, :ohmy: a D2EA 4bolt block fully balanced rotating assy with 12.5 TRW raised pistions.

Using that base I added a few extra goodies to it and it cranks out 617hp/527tk at the flywheel. :001_tongue:

[Ash 145]

A bit off the subject, but what is a good running Cleveland worth?

 

I'll be pulling my Mach's healthy Cleveland, and Top Loader 4 speed, to swap in a 408w/5 speed combo. The motor will be complete, from carb to oil pan.

 

This may seem like a silly idea to some and it also may not go anywhere, but why not have a go at listing it on Aussie ebay? Our dollar is very good and if you are willing to help have it crated up, you may have some luck. Especially with a top loader and all parts. The top loader and manual conversion parts on their own could be worth up to a couple of grand maybe.

 

And if your car is like many other US cars without an engine number, this would be a huge selling point in Aus. Hint hint wink wink :wink:

 

Watch our ebay for a little while to see what they are selling for at the moment, not there would be a great lot of choice like you guys have. But for the sake of a few bucks to list and especially if Clevos aren't selling for much over there, why not. They are big selling engines here at home as they would be the most common in older Falcons. Even at a quick guess at a value for something like that here, would be a 5k min start.

[Powershift 19]

Never thought about Aussie Ebay. Thanks for the tip!!

 

Oh, and Mach1Rider.... As far as price, if all I could get for it was $500... I'd rather put it on an engine stand for display in my living room!! HA HA!! Nice score on your D2EA block. I would think that's a a great deal, and not the norm.

 

But, I also know it won't be the easiest thing to sell. I was just going for a ballpark idea on value.

Edited March 7, 2012 by Powershift