new stroker build, some issues

[wjtom]

If the sound gets louder with speed and rpm and it sort of resonates inside it most likely driveline.Probably a driveshaft or pinion angle problem.Or both.I can tell you for absolutely sure if the driveshaft is not high speed balanced (meaning past 4000rpm)it will shake badly especially in overdrive and 5th in your case.Luckily for me after 3 driveshafts i went to dennys (yes the same guy on the tv shows)which is right by me and no more problems.If it was floating valves that bad the motor would have a noticable decrease in power at that point.Leads me to believe its driveline.I would definitely get it taken care of because it will destroy pinion bearings in a very short time.Like a few thousand miles.Ask me how i know?lol

[6TIME]

If you have vibes within the motor/clutch they should be consistent with rpm only. By revving the motor in neutral, it should differentiate your vibes from driveline and engine making them easier to locate. Out of the 4 strokers that I've put together, they all seem to have a slight harmonic vibe in the 4-4.5K range depending on the crank weight and pistons used. It will vary depending on the combination of these parts tho. 4cw Crank with the old heavy 677p cast pistons seem to be the combo that has more noticeable vibes. 12cw cranks help smooth things out.. If you still are using stock valve springs? Put some better ones in! The 232 cam shouldn't fall flat @4k! I'm blaming your old valve springs.....Glad to hear you got it running better this time around!

[SilverXJ]

x2. You need better springs with the 232.

[sly-jeeper]

don't forget to check the front u joints by the t-case ive seen the inner bearing go out and throw the balance off so far it literally snapped the front drive shaft portion of the t-case off while going down the hi-way

[SilverXJ]

Try removing the front shaft and see if vibes are still there. If so, put the front shaft back in and put it in 4x4 part time and drive it and see if the vibes are still there. The front shaft's slip joint can cause vibes if it has wear. Same for the rear if you have that style shaft there.

[danimal]

Oh I know there are driveline vibes. I welded up my own driveshafts and they are not balanced. I bent or twist them fairly often so I don't bother balancing them. But the vibes aren't just that I don't think. It could be harmonics from the motor or it could just be harshness from the valves not closing completely due to the valve springs being too weak. Ill investigate when I have time and money. Right now it's getting the trans pulled because the slave cyl went bad. Ugh. I wish I had the cash for an external slave cyl swap.

[the grey ghost]

Someone here in Houston is selling the kit with the bellhousing on craigslist , heads up

[danimal]

yea there's some in the junkyard, i just dont have the cash for one right now. i got it fixed at the dealership, i traded labor for labor on their class 1 car, so it didnt cost me a penny. i would have done it myself, i was just so over it at this point.

[Cheromaniac]

Right now it's getting the trans pulled because the slave cyl went bad. Ugh. I wish I had the cash for an external slave cyl swap.

Tell me about it. I just had the clutch slave cyl, pipework, and master cyl replaced on my Jeep a couple of months ago after my clutch pedal suddenly went soft. My heart sank when I saw clutch fluid dripping from the bellhousing. Luckily I was only a short distance from the workshop so I managed to limp the Jeep over there and since the tranny had to be dropped anyway, I had the clutch plate replaced as well (old one was still only half worn).

[danimal]

yea, i lost my slave 3 times so far in the past year. once it was the original one with 230k on it, the next 2 were in the past week or so


So someone gave me some LS1 springs yesterday. I cannot find solid info on how much i need to machine the valve spring seats or what the closed height needs to be with these springs on my head with stock valves and ls1 retainers. I know the diameter is too small to fit over the valve guide boss, so that needs to be changed. other than that... anyone got any ideas?

[6TIME]

Typically they are set up around 1.8" There are a few different LS beehive springs out there, so you might want to have them tested to see what flavor they are.. Are they painted or have a orange stripe? I've been running LS1's for a few years and they work great. I have run the blue LS6 springs on many healthy SBC builds and they have worked excellent also. The ID on the valve spring seat will need to be reduced to .855" or less for them to sit properly. You can snag a spring seat cutter like a Comp 4716 and do it yourself for 50 bucks, or pay the shop. I have about 4 different LS springs sitting around so if you can Id. which ones you have I can test them up for ya. BTW, what locks are you using?

[danimal]

ok so people are using the standard 1.8" for ls1 springs, huh.
The springs i got are from my buddy's nascar, so they are not stock. they should be 120# closed and about 275# open with my cam. I will be testing them before using them though. The paperwork was in the box with them.
I'll look into that cutter but i was considering making one myself. I have a small machine shop (not engine machining).

Thanks for the info!

[wjtom]

I understand your reasoning for the driveshafts but if you arent balancing them and making your own but you cant believe the harmonics it will create.Your problem sounds very similar to mine.I only had vibration that was noticable in 4th over 50mph and it was so bad you really didnt want to drive it at that speed or anything faster.Found one shop that did a better job balancing it at 1300rpm but still not right.Had denny do one and balanced over 5000rpm and the problem was gone. Dennys driveshaft has a guarantee if you can twist or bend his he will replace it for free.I know nobody wants to spend 400 dollars for a driveshaft but just remember those vibrations are trying to destroy the driveshaft itself(causing it to break-tube size,length,rpm come into play here go on danas website )along with the rest of your driveline.

[danimal]

I understand your reasoning for the driveshafts but if you arent balancing them and making your own but you cant believe the harmonics it will create.Your problem sounds very similar to mine.I only had vibration that was noticable in 4th over 50mph and it was so bad you really didnt want to drive it at that speed or anything faster.Found one shop that did a better job balancing it at 1300rpm but still not right.Had denny do one and balanced over 5000rpm and the problem was gone. Dennys driveshaft has a guarantee if you can twist or bend his he will replace it for free.I know nobody wants to spend 400 dollars for a driveshaft but just remember those vibrations are trying to destroy the driveshaft itself(causing it to break-tube size,length,rpm come into play here go on danas website )along with the rest of your driveline.

Yea ive been driving on unbalanced driveshafts for a while. I'm aware of the vibes. I can't spend money on driveshafts for a while, and i rarely take it on the highway for very long, so i'm not worried about it.

The motor has a harshness to it, much different than a drivehshaft vibe, and it's different than my old motor with the same driveshafts and the same everything else.
The motor won't go past 4500 in second or third gear. It may not go past 4k in 4th or 5th. It hits a wall, kind of like a rev limiter. I am really suspecting valve float. The valvetrain clatter is a little worse now as well. I need to get some retainers and get these ls1 valve springs on it sooner than later i think.

[danimal]

well i scored some ls1 retainers last night, and while i was there, he was nice enough to check my ls1 spring rates.
Closed pressure (1.800" height) 118lbs
Open pressure (1.31" height) 300lbs
Is the 300lbs going to be a problem with wiping out my cam lobes?