Muggard

Hello everyone. I'm a newer member and this is my first post since I've joined. I've been doing a lot of searching on this site, along with other investigating, and have now decided to ask some questions based on my specific issue / application. I'm sorry for the long post, but I'm trying to cover all the angles.

My 455 was fully rebuilt 3 years ago and dyno tested, everything went well. Within 40 miles of driving, the engine started making noises. The builder took back the engine on two occasions to try and find the issue. 1st time he changed the main and rod bearing even though they looked fine, no luck, same noises. The 2nd time he completely dissembled the engine to check everything. Supposedly everything looked good with no obvious ware to the bearing, cylinder walls, valve train components etc. At that time I had him install a new Eagle crank because I wasn't convinced that the existing crank, which they originally machined, was ok. I also had them dyno the engine again to check for noises. At that point all was well, engine sounded great!

This was December of 2016. I finally got a chance to install the engine in May of 2017. Engine ran well for the first 250-350 miles with no abnormal noises. Then, the same noises started again.

The noises I'm hearing sound like a "chattering" or maybe "clattering" from the bottom end when listening under the car from either the drivers or passenger side. Also, there seems to be valve train noise from the top end that sounds like a "sewing machine" sound. Not sure if these noises are all related. There is no question that these are internal engine noises. In general the noises are more notable on a cold start up and seem to get a little better after the engine initially warms up but then get worse once again after the engine has been driven for a while with hot oil. After driving at thruway speeds and especially after a WOT acceleration, the chattering and machine sounds are much more notable at idle. Almost sounds like the engine is going to rattle apart. Overall the noises will lessen after I sit at idle for a few minutes, or after I shut the engine off and let it cool for a while. Either way, there is still some sort of chattering or valve train noise no matter what temperature the engine/oil is at.

While accelerating, I can hear what I'm assuming is valve train noise from the top end but no noticeable knocks. Also, more recently (late last summer this spring) I've noticed a hard "tapping" sound that is more apparent after the engine is fully warmed at both idle and while cruising (less noticeable under acceleration). Sounds like excessive valve lash in one lifter that seems to be coming form the #5 or #7 cylinder. I removed the valve covers and checked valve lash (which should be zero) on all valves using the EOIC method. All the valves seem to have zero lash based on the fact the I can spin the rods with minimal drag and no up/down movement.

Throughout this entire adventure, oil pressure is ~50psi (cold idle), ~25psi (warm idle), ~45psi (warm engine cruising) using 10w-40 Brad Penn oil. I never noticed any oil pressure issues.

The original engine builder has since retired. I've found a new engine / machine shop and explained the whole story. He is going to take my engine apart and go through everything, check all tolerances, clearances, any excessive bearing wear, piston slap etc. Then from there determine what needs to be done to render the issue.

Questions;
1. Any thoughts on what the noises may be? I'm trying to arm myself with as much knowledge so I can work through this with my new builder.
2. I've decided I would like to investigate going with a hydraulic roller set up and adjustable valve train since engine is coming back apart.
a. Anyone have a suggestion for a hydraulic roller cam selection for my application?
b. Also, any suggestion for a hydraulic flat tappet cam just in case I decide not to go with a roller setup? At this point, I will not be installing another Comp flat tappet cam. Personally, I think the cam / lifters I have, see below, is part of my current noise issue.

The engine was set up with a stock valve train, Comp XE268H (#42-223-4) –.485/.49; duration @.50” 224/230; 110 lob separation. Dyno results with this cam and the following engine specs. where 328hp @ 4,600rpm, 419 ft/lbs 3,200rpm. This was with the stock cast iron manifolds installed.

Current Engine specs. / parts.
- 468 (.060" overbore + .006" to account for piston expansion)
- Sealed Power Pistons #L2323F60
- 9.5:1 CR
- Stock rods
- Dual plan Edelbrock aluminum intake
- 750cfm Edelbrock carb
- Stock, case iron exhaust manifolds (X, Y)
- Cast iron F heads (small valve)

Installed in a 1968 Olds 442:
- TH400 transmission (Automatic)
- ~2400 stall converter
- 3.42 rear gear
- 25” tall tires (stock size on 14x7 rims)
- Power brakes (require 14 inches of vacuum)
- 2 1/2" Mandrel bent exhaust with "X" pipe (Pypes)

This has been a frustrating experience for me which as cost more $$$$ than I wanted to originally spend. Any suggestions and help would be much appreciated.

Thank You,
Muggard

cutlassefi

My first guess would be piston slap, those aren’t the best ones out there by any stretch.
Second part would be the Comp cam. They can be noisy sometimes. Running a stock valvetrain with it doesn’t help either.
Check our some of my builds on here, maybe those will help too. I’ve posted a bunch.
For best results I’d change the carb too, it’s too small for any performance 455.
Hope this helps!!

Fun71

Small valve F heads? I thought they were all big valve. If they really are F heads, sell them, buy a set of aluminum heads, and put the leftover money into your retirement account.

jpayne_80@hotmail.com

Crank hitting the oil pan? I didn't realize there was a dent in the oil pan and when I first fired up my 455 I freaked out due to the noise. I posted a video and someone told me to check the pan. Sure enough there was a tiny dent but just enough for the crank to hit the pan. I was so relieved when I found out that's all it was.

matt69olds

Cut the oil filter open, use tin snips. Look for copper or other debris in the filter. If that’s all good, you can be relatively sure the noise is in the valvetrain. Closely inspect all the rocker arms, check the valve lash, etc. with the stock valvetrain, I’m betting your going to find some lifter preload issues.

Muggard

If it is piston slap, I'm I in trouble with the current bore of the motor if I were to get a different set of pistons? I have another block I can use if I need too. Do you have a piston manufacturer suggestion?
I agree with the cam. My original builder talked me into it. Based on my current specs. Do you have a cam suggestion?
Thoughts on a carb selection?
I plan on switching to an adjustable valve train.
Thanks for the info thus far!

Muggard

Sorry, they are E heads. Yes, I know I can do better but, for what i use the car for, the are good enough. Plus, I don't want headers. No sense in upgrading the heads without headers.

The oil pan is branch new and the builder confirmed with was not hitting.

Muggard

I was mistaken, I have E heads. I know they are not great but fine for my application. I run stock manifolds and I'm not interested in switching to headers, thus, I don't see the need in upgrading heads right now.

Muggard

I plan on having the new machine shop cut open the current oil filter. Unfortunately I don't have my old oil filters (from two previous oil changes) and the current one has less than 60 miles on it.

Muggard

Oil pan is new and is not dented. The original builder did check for clearance last time he had the engine apart. There were no issues.

BillK

Don,
I have also heard that the Comp Extreme energy cams can be noisy but I would think they would be so from the intial startup, not after 40 miles. Aluminum valve covers can also really amplify valve train noise.

If you have not already started taking it apart one thing you absolutely should do is drive the car down to the machine shop and let them listen to it. A lot of times someone with some experience can pick up on a noise like that. I always like to hear it if I can before the engine comes out to be torn apart. I have a long mechanics stethoscope that can really pinpoint noises sometimes.

BillK

Do you know that for a fact ?? Piston clearance is designed into the piston. A .060" oversize piston is designed to run in a .060" oversize bore. If your original guy actually did finish the block at .066" oversize, there is a pretty good chance that is your problem. The L2323F pistons are designed to run at .003" clearance. That means the piston would measure 4.182" If your guy actually did bore it to 4.191" it has .009" clearance and would definitely be noisy

Muggard

I have a stethoscope too. I can't find anything specific (I am NO expert) except for a hard tap, possible a slight knock, when I stick it to top of the cylinder head next to the #7 spark plug. It's consistent with RPM. I've already mentioned this to the new shop. Everywhere else I check (ie: valve covers, oil pan) it mostly sounds like a sewing machine.

I have a video from last July with the valve covers (stock) were off and engine running. I will try to post it this weekend when I get a chance. After I took the video last year, I drove the car to the old builder to see what he thought. That's when I found out he was closing up shop. He just figured the noise was from the cam / value train and that I shouldn't worry about it (yeah, I know) because everything looked good internally when they took it apart the year before.

I was going to drive the car to the new shop this year, but it's farther away than the old one (~40 miles round trip) and I wasn't so sure that was a good idea since it appears the noises may be getting worse. Plus, I've already started taking the motor apart. It will be out of the car tomorrow morning.

Muggard

I thought that's what he told me because I specifically asked that question when he last went through it, but I may be wrong (I don't have the paperwork for all the machining specs. That is my mistake for not getting that info.). The new shop will need to verify the bores.
So basically if it is over bored, the block is junk and I need to use my reserve block and have that prepped for the rebuild. I'm hoping this isn't the case, but only time will tell.

BillK

Either that or have some custom pistons made. I am not familiar enough with those blocks to say if it is ok at that size bore. You could sonic test it to make sure.

Kennybill

I have those pistons in a near 20 year build. I asked my Machinist/friend for .0045 clearance. I'd known him since grade school till his passing, over 60 years. He said to me, "by the way, you GOT your four and a half" when I picked it up. Lol, The engine went 11:17 in a G-body. Engine "de-cammed" is in my turquoise 98, still running good. (14:13)
I would start with another block and inspect and transfer your rotating assembly, yada yada. BTW, I have std bore blocks and I'm 3 hours away but wait there's more, I'm heading to Niagara Falls around July 5th, give or take a couple of days. "Just saying, ha ha." If you want to talk, pm a phone number. Either way, I think you have to much piston wall clearance. Good luck, Ken

cutlassefi

X2, 4.190 is very popular bore size, essentially a .040 over 455 Pontiac.

scott442

You didn't mention the new builder but looks like you not far from one of the best Oldsmobile builders in the country.

http://btrperformance.com/

Muggard

Here is a link to a video I took from last July. Not a great video. The valve train noise is pretty clear, but the chattering I'm hearing from the lower end is not. However, if you listen closely there is a inconsistent tapping sound from the lower end which is weird.. Note that I say "no oil" as I didn't see much oil supply to the rockers. The engine was cold at this time. After the video, when the engine warmed up more, all the rockers were receiving oil.

https://photos.google.com/share/AF1Q...hLT2hoX190d2VB

Muggard

First I need the current bore verified before I do anything. Thanks for the block offer, but I already have another on in my possession plus a buddy who was one sitting around he's been trying to sell me for years! Enjoy your trip to the falls!

Muggard

I'm aware of BTR. I actually have his book! He is not my builder though. I have another builder closer to where I live.