On balancers and cam endplay

[cv67]

383 sbc see thread below
viewtopic.php?f=1&t=41137
Need an SFI balancer thats not junk. I know ATI is the fav funds just dont allow it period
Have a streetdampner on now thats pretty old suspicious of it

Machinist said my cam enplay (solid roller) was set at .007-.008
Plan on pulling the intake using a dial indicator to check
Good opp to check the conditions of the lifters also

Trying to solve the issue of timing mark dancing around and a slight vibration issue
Cant be good for my bearings dont want to blow this thing sky high.
May as well flow the intake, too.

Suggestions?

[raceczar]

Doubt it's the balancer.

If it shakes it's because the balance job is incorrect.

Yes, I read your other post.

[lorax]

No harmonic damper is going to get rid a shake that you can see or feel unless its the wrong damper, as in an external counterweighted one verses a internal neutral balanced one.

[stokerboats]

No harmonic damper is going to get rid a shake that you can see or feel unless its the wrong damper, as in an external counterweighted one verses a internal neutral balanced one.

Did that in 1970. Put a 427 balancer on a 454. Boy did that ever vibrate.

[cv67]

Its between 2400-high 2s.Cant feel it under throttle only steady speed
Or if I have my hand on the valve cover feels like a slight shudder. Motor doesnt "shake" visibly

Id be bummed if I had to tear this thing apart..again. Esp with no garage now

Guess Ill start with fueling, ie basic stuff go from there

Machinist who specializes in balancing says he has alove/hate thing for those balancers says they work fine under throttle/load but steady rpm they dont do much of anything to get a real 2 pc damnper on there. Guess well see.. :sigh:

[kirkwoodken]

Wrist pins being too tight from being installed wrong MAY cause a vibration in the RPM range you are talking about. I had a dealer warranty repaired engine that a mechanic had installed pins with a press, not heating the rods,and most of the pins had gauling. (Sp.) Pistons were squashed, bores distorted. Had a similar vibration. Just a thought I know you didn't want to hear.

[raceczar]

Its between 2400-high 2s.Cant feel it under throttle only steady speed
Or if I have my hand on the valve cover feels like a slight shudder. Motor doesnt "shake" visibly

Id be bummed if I had to tear this thing apart..again. Esp with no garage now

Guess Ill start with fueling, ie basic stuff go from there

Machinist who specializes in balancing says he has alove/hate thing for those balancers says they work fine under throttle/load but steady rpm they dont do much of anything to get a real 2 pc damnper on there. Guess well see.. :sigh:

Not sure I believe the machinists thought there. As long as there is rotation, the dampner has ZERO idea what load is on it.

Seems you are predetermined the dampner is a fault here. Make sure you don't step over donuts to pick up dog turds.

[stokerboats]

What type pistons?

[JoePorting]

Doubt it's the balancer.

If it shakes it's because the balance job is incorrect.

Yes, I read your other post.

I doubt it's the balancer either. Also doubt it the balance job. I assume a bad balance job would vibrate more as the rpm's increased. The dancing timing mark is from your distributor advance. Go with a locked out distributor and your timing mark will be a lot more stable. As mentioned in your other post, I would lean out your carb and double check your entire ignition system.

[cv67]

Lets hope its not the balance he specializes in it and does many for surrounding shops for decades.

Probe forged small dome pistons floating pins

Ill start with the carb and ck the dist for any slack it sholdnt have.
Had Bob Jennings curve it...pulled it back out of the car stuck it on his Sun Machine again all seemed well. Ill find it I suppose was hoping to narrow down things so Im not tearing this whole thing apart.

[Dave Koehler]

Don't forget what is hanging on the other end of the crank.
2 other thoughts.
Is a little vibe to you the same as to someone else? Is it a Hum as opposed to the engine visibly moving?
Do you race or cruise at 2800 rpm?

I vote for a tuning issue.

[Baprace]

If I remember correctly, this particular engine vibe was discussed at lengths a year or so ago, it had dual ex side pipes mounted pretty rigid.....

[Dave Koehler]

Good Grief, Really?

[cv67]

That thread with the sidepipes was from someone else had a C4 corvette I think

Motor doesnt shake visibly I cruise between 25-3000most times

Spoke to someone on this board yesterday sounds like some time really spent nailing down fine tuning is the answer rather than parts- Time to finally put an A/F gauge on it and dig in.

Been through a handful of motors on this car with not great results want this one right.

[racear2865]

why pull the intake to check cam end play. just yank or knock out rear cam plug and measure cam movement
reed