Gauge

iTrader: (3)

Hey guys,

I just finished my first engine rebuild in my garage last week. It took me on the order of 3 months to get it all done. I'm a little concerned with how much noise the valvetrain is making, and I wanted your opinions.

Here is what I have:

- stock heads milled .040"
- .040" Cometic gaskets (total .054" off stock heads/gaskets)
- TR 230/236 cam
- Comp 850-16 lifters
- Comp 7.350" PRs
- Crane Cams dual valve springs

I have a PR length checker, and here's what I did. I put the cam and lifters in. I torqued down the heads nd then dropped the checker in at 7.250". I made sure the cam was at no lift (lifter on the base circle) and torqued down the rocker to 22ftlbs. The PR checker was loose. I tried again at 7.300" and the checker was stuck. Per previous advice from a guy at the machine shop, I added .050" to that number and ordered the 7.350" assuming this would give me in excess of .050" preload (which is what I was told I need).

The car seems to be running great (thank God because I'd have offed myself if it hadn't), but the valve train has a very loud sewing machine sound. If it's normal, it doesn't bother me, but I want to be absolutely sure that it is before I stop worrying about it. I'm thinking that my PR length might be wrong or something.

Today I cracked open the valve covers and looked around. I checked the torque on the rocker bolts (which I did loc-tite), and they were all good. I wiggled the PRs, and they were all snug in place. The only movement I could get out of them was just the slight side-to-side movement you can get out of the rockers.

Anyway, I don't know what else to check, and I need to set my mind at ease. I can post a vid if it would help you guys. Lemme know if you need any additional info. Thanks!

Viper

iTrader: (6)

For more piece of mind, you can do two things.

1. Get your stock rockers rebuilt by harland sharp. I had severe side to side action before I had them rebuilt, it helped my valvetrain noise. Around $250.00

2. Measure the PR length again. I know, you measured it once but myself I ended up redoing the valvetrain twice after hearing noise till I got it right.

DuronClocker

iTrader: (25)

Don't use just one lobe to determine pushrod length. Go through a few of them to make sure you get the same result on all of the ones you test. I had a lot of noise with the stock 7.400" pushrods, and then I finally measured and determined I needed 7.350" pushrods. Cut my valvetrain noise at least by half.

How "tight" was the checker at 7.300"? When I did mine, I made the checker intentionally a bit too short and then torqued the rocker down, and then made it longer until the pushrod could no longer be moved up and down (could spin easily though). Took that number and added around .080 to it I believe. Its been a while now, but I had followed some directions that I'd seen on here often. My ideal pushrod length was somewhere between 7.325 and 7.350, but I erred to the high side and got the 7.350s.

DaddySS

preload should be .060 to .100, many prefer about .080. Mine was at .050 and noisy and at about .080 they are incredibly quiet with XER lobes.

As stated above, important to check a few or check them all, and I would plan on 7375s or 7400s.

Gauge

iTrader: (3)

I appreciate all the input, guys. I haven't had an opportunity to do much to the car yet. I checked the torque on the rocker bolts, but I haven't had enough time yet to use the length checker on some other lobes.

I need a way to gauge "noisy" and "quiet," though. Currently, when I'm cruising in 5th gear at 1500 RPMs without any throttle, I can hear the valvetrain from inside the car. If I press on the throttle, however, the exhaust will drown it out. How does that rate on the scale of noisy to quiet?

Also, does the noise indicate that I'm somehow doing damage to the engine by running it? Or is the noise the only real issue caused by having too little preload? Keep in mind that I've got at least .050" if the lobe I checked is any indication.

Z'mnypit

iTrader: (58)

.050 preload on the comp 850-16's is enough. I normally shoot for .040-.060. I did one this weekend that had cartek heads shaved .030, block decked .010, cometic .040 and when I checked the length I came up with 7.19 + .050 preload = 7.24 so I did a 7.250 PR and it cured all tapping/ticking.

Do you have a "sewing" machine sound or is it a loud tapping/ticking noise. Your going to have some noise because of the extreme lobe rates, and stiff springs.

Gauge

iTrader: (3)

It sounds like a sewing machine. It is so hard to distinguish from when I had the bolts back out of the timing gear, though, that I'm very concerned about it. The only difference really is that there was a slight tapping sound before and it was much louder. Otherwise, it sounds very similar.

I will try to post a vid tonight, and I think I'm going to run it by the shop I bought the PRs from and see what they think.

GuitsBoy

iTrader: (4)

Its probably just the normal sound when you're on the low end of the preload spectrum. Looks like you did everything correctly as far as I can tell.

Gauge

iTrader: (3)

I took the car to LG Motorsports (the guys I bought the PRs from) and one of their techs came out to listen to the car. After listening to it while pulling back on the throttle cable for a few seconds he stood up and said, "You did a good job. It's fine."

At this point I'm going to just stop worrying about it until it breaks. I have all the tools and knowledge to rebuild the engine again if I have to. I just don't want to.

GuitsBoy

iTrader: (4)

Then congrats once again dude!

Patrick G

iTrader: (14)

Probably just the typical valvetrain noise that gets amplified by headers and stiffer springs/faster ramped cam. Click on the idle clip in my signature and listen to the underhood portion. I have very good pushrod plunger depth. XE-R and LSK lobes with stiff springs will tend to be a little louder, that's all.

Byter

iTrader: (1)

Patrick, thank you very much for that clip! I've always agonized over my valvetrain noise, but yours sounds just like mine, so I feel better. I still may go to a less agressive lobe, but at least I know its not because of my install.