Big Problems with New 408 +PICS

[dust]

• Cylinder 7 Intake lifter will not pump up and making noise.
  
• Carbon/Oil deposits on valves of Cylinder 7
  
• Thick ridge on Cylinder 7 compared to others
  
• Smoke coming from left tail pipe at midrange RPM. Or when after high RPM and let off gas, we were unable to tell which or if the white smoke had blue in it

Specs: 408 Eddy heads, 650 Mighty Demon, Racer Brown .470/232 and lifters, HV oil pump, CC Pro Mag rocker arms. 4 speed. At most 200 miles on engine and 2 runs.

Ideas?

[dodger1]

Wiped cam lobe? (Hope that's all!)

[ehostler]

bad lifter, wiped lobe, or short push rod. Those are my guesses.

[DAHEMIKOTA]

White smokes indicates water in the cylinder. Water in cylinder says blown head gasket or cracked head or block. Water in cylinder will cause the rings to wear the cylinder because of lack of oil. Just my .02

[Robertson_Tech]

Did you run a compression test? If # 7 lifter was real bad maybe the rings did not seat. Now that you have the head off use a dial indicator to check the lift on the cam. Run the piston down in the hole for #7 how do the cross hatch marks look compaired to the others? I supect the ridge is just carbon did you build it or have some one else?

[TK]

Rings too tight.

[dust]

Originally Posted by ehostler

bad lifter, wiped lobe, or short push rod. Those are my guesses.

Good guesses.
Lobes are fine, actually the one with the bad lifter was a little larger than the others at .471 where all the other were are spec, .470.

Visually, pushrods look identical.

[ehostler]

If you already confirmed that you had a bad lifter, then why ask what the problem was? Replace the lifters, clean up the head, reassemble and go.

[JLM440]

Honestly what i think is you have bad rings or bad guides, thats oil in that cylinder & on the valves, looks like its been missing for awhile.

[dust]

Originally Posted by ehostler

If you already confirmed that you had a bad lifter, then why ask what the problem was? Replace the lifters, clean up the head, reassemble and go.

But what about the ridge? And why did a brand new lifter go bad?

[TK]

Dirt, or grime, somewhere......

And, what about that ridge? Were the rings gapped correctly?

Shit Dust, you think you have problems, I have a groove in #8 cylinder half way to china from a pin lock, in my 390.

[pishta]

Originally Posted by TK

Dirt, or grime, somewhere......

And, what about that ridge? Were the rings gapped correctly?

Shit Dust, you think you have problems, I have a groove in #8 cylinder half way to china from a pin lock, in my 390.

how about a bad valve guide, passing oil at high vacuum conditions, ie. getting off the gas. Can you pull the valve spring and check valve tension on it? if it binds at temp, itll stay open and the lifter wont be able to take up the slack. Eddy heads are notorious for having poor valve machining, some head place has it priced right in their labor chart. I had a pin lock fail and it dug a ditch in the 4 stroke motorcycle cylinder too, talk about smoke, like a sky writer!

[TK]

Well............it didn't smoke really, but it dug a nice groove. Really screwed on the stroker, because the pin is so far up in the piston. It's pretty neat!
First time I have ever had this happen too. As much as I hate sleeving, I think it will be my answer, I need a custom made TRW piston too........

[aarracer]

Hey

Do you have the oil galley plug in the rear of the left bank oil galley? (In front of the distributor hole, down by the oil pump drive gear)!

This plug not being in will cause an internal drain right at number 7's lifters giving almost 0 oil pressure in the left side galley and resulting in lifters not pumping up (although it will still support sufficient pressure in the right galley to run the engine).

Cheers

AARRACER

[dust]

Originally Posted by aarracer

Do you have the oil galley plug in the rear of the left bank oil galley? (In front of the distributor hole, down by the oil pump drive gear)!

This plug not being in will cause an internal drain right at number 7's lifters giving almost 0 oil pressure in the left side galley and resulting in lifters not pumping up (although it will still support sufficient pressure in the right galley to run the engine).

Thanks for your advise but can you be a little more specific where this plug is? I’ve never installed one, nor have I even knowingly seen one.

That reminds me… I saw something called an ‘oil slinger’ in a small block build in a magazine. I don’t think I installed that, is it n

[DAHEMIKOTA]

It is directly in front of the outside plug in the picture and ahead of the distributor/oil pump drive gear. Dan

[Tarrbabe]

Start from square one and make sure you don't have a bad part. I have changed to a new set of plugs at the track and had it miss like an engine that had 1000,000 and no tune-up.It back-fired thru the headers all the way down the track even thouigh they were set correctly. Only after you eliminate the EVERYDAY problems, can you correct other problems. I hope you find your problem soon.

[Tarrbabe]

then it must be a problem with the ring/piston set. Nothing else can do that that I know of. Broke ring? Wrong ring gap? Wrong bore?
You shouldn't be showing wear unless something is off deminsion.

[TK]

Wrong ring gap.

[George G. Leverette]

What type of rings are used. Were those " 2 runs at the track" with only 200 miles on the motor? Strokers are not high RPM engines, appears to be an oiling system problem.

[TK]

Just a quick question, what makes a stroker a low RPM motor?

[pishta]

Originally Posted by TK

Just a quick question, what makes a stroker a low RPM motor?

crank throws farther from the centerline. Remember your BMX bike cranks? the longer they are they easier to pedal, but you just cant go as fast. Its like riding a cheap 1 piece short 160mm crank Huffy 10 speed, and then riding a 3 piece Sugino 185mm crank Nishiki. Weak comparison, but I got it...Ford 5.0 makes good HP for the displacement but is not really a torque motor, the rods are very short.

[Tarrbabe]

Stroker motors are condisered lower rpm motor's because the longer stroke of the crank. There is a much larger weight mass to deal with because it travles farther than the center of gravity, which increases the force of the rotation of the mass. Anytime the rotating force increases, the imbalance increases on the block that takes the force to itself to mean that even though the mass is in balance, it has a larger external force. As force is added to the block by external forces the pressure is elivated to another level. This is why blocks crack and fail
If you keep the forces inside the strenth of the block, there is no problem. This includes the forces that are restricted by the proper balance of the engine.
A properly balanced rotating mass will take much better care of a block that was not formerly capable of absorbing the pressures applied to it.
The early strokers were peice mill and a lot of the engines tested failed due to the external failures put to them


Bottom Line/////////////////////Have your engine balanced to the HIGHEST level to prevent Block failure. That is why some engines bottom ends fail at 6000 rpm and some live at 8000 or more.




Just thinking our loud.
Hope this helps

[Robertson_Tech]

One other factor in limiting RPM in a stroker motor is piston speed. A longer throw with the same rod lengh will have higher piston speeds.

[oldguyalso]

It's sorta like twirling a ball on a string. The shorter the string the faster the ball twirls. And vice versa, of course. Seems like I vaguely remember something about the Polar Moment of Inertia. LOL God, I love getting old!

[Dukes2fast]

Originally Posted by Tarrbabe

Bottom Line/////////////////////Have your engine balanced to the HIGHEST level to prevent Block failure. That is why some engines bottom ends fail at 6000 rpm and some live at 8000 or more.




Just thinking our loud.
Hope this helps

What does balanced to the highest level mean exactly? I was not aware you could balance to an rpm level...I had mine balanced but don't know to what "level" it was balanced.

[Dick]

Engine balance is a good point of discussion but it should be in a thread devoted to same.

Our OP is in a mess with a potentially serious problem in his 408. Let's not divert the thread away from that subject. Thanks.

[pishta]

Originally Posted by Dukes2fast

What does balanced to the highest level mean exactly? I was not aware you could balance to an rpm level...I had mine balanced but don't know to what "level" it was balanced.

Balanced at 6000 means the total imbalance will not affect the motor at 6000 on the balance machine. Run the machine to 8000 and it will magnify the imbalance the 6000 could live with. Run it to 10000 and youll see some that 8k missed. Modern balance machines are pretty good but you could be balancing a crank for hours to get perfection only to lose it on a rod or bearing pack, piston, ring, etc.

[Tarrbabe]

Any engine with 200 miles should NOT have a ridge in the block. Oil splash should keep the cyl's lubed so their shouldn't be a problem with the oiling. A stroker places the pin high in the cyl. and thus causes more pressure at the top of the piston travel. If you have wear, it is because of excessive pressure at the top of the piston or incorrect rings. The only other thing to consider is vibration causing increased pressures. The rings should be checked / mic'd and look for any problems. The reason I mentioned the balance is that vibrations magnify points of stress. Mic the piston, rings and block to check for correct fit.
Also it appears to me that the valves are NOT sealing well as is clear in the pix.

As I remember, they use to run the Offy 4 bangers at Indy at 16,000 rpm. That takes some fine balance.

[santtu]

dust, anything new?