Bent pushrods

The engine for my rig is still on the engine stand. Its a freshly rebuilt 5.9 Magnum. .040 over, 9.5 compression, a solid towing cam, and everything assembled to spec. It was originally built for a Dakota i had but I could never get it running. I think I found out why. 1 pushrod in each cylinder is bent. about half are intake & the other half are exhaust.
I've been through this in my head a few times. Not that it would matter at the 100 rpm that the starter turns the engine but the springs are matched to the cam. The heads are brand new RHS. The valve timing is correct. The pushrods I used were new but I can't remember if they were hardened. I don't see why that would matter with a mild RV cam. Any ideas???

Pic
https://2img.net/h/i234.photobucket.com/albums/ee94/travis4prez/100_2555_zps7a10121e.jpg

"A solid towing cam" you mean it's really a solid lifter cam?

You have a big problem to cause that cranking.
Please write and/or show pics of the valvetrain (cam, lifters, rocker arms. springs and retainers) and describe what was done to the engine when rebuilt.

"A solid towing cam" you mean it's really a solid lifter cam?

Its a roller hydraulic cam from Hughes Engines.

they sure look used to me.

Yes they do an I could be wrong but I am almost certain that I put new ones in there. Even if they weren't new, why would they bend?

The cam is in there correctly. When I couldn't get it started, I pulled the front apart to make sure i had the timing set at TDC. The gears are at 6 & 12 an the marks are lined up.

I can get some pics today after the sun comes up and I will pull the heads to make sure the valves didn't kiss the pistons. I will let you know what I find.

Thanks all

Hughes lists many different lengths of pushrods for the magnum.
Magnum style

Have you checked all the lifters to make sure they are all the same height? Were all the pushrods the same height?
Was the block decked, the heads machined from RHS?

From the Hughes site

The proper pushrod length ensures that you can obtain maximum lift from your camshaft and have the most stable valve train for high RPM operation. If you are unsure about what pushrod length you need, use our length-checking-pushrod tools (Contact us for details). Remember, just because your rocker arms may have an adjusting screw it does not mean the screw is there to make up for a pushrod that is too long or short. The adjusting screw is only to set lifter preload or valve lash.

So, I would suggest getting all your engine info written down and call Hughes and find out what pushrods you need. You may also need upgraded rocker arms and other valvetrain parts.
I would also pull the heads and have the valves checked. A quick leakdown should tell you. I bet they kissed the pistons!

I'm not elbows deep in magnums, so I can't pluck the magic answer out of the gray matter.
I will repeat the advice to call Hughes. They have a good reputation and should be able to help you find and fix the problem.
Go in asking for help, not bashing their parts.
Understand that

everything assembled to spec.

did not happen, because nothing done fully would bend stuff like that.

Everything is stripped down. The pistons look good. the valves look fine as well. In turning that thing over, it looks like the exhaust is opening up sooner than it should. I have a degree wheel but its a touch too big to make it by the crank. i will pick up smaller one and degree the cam tomorrow. Didn't do that during the build.

The lifters are all the same and so are the pushrods. At least to the hundredth of an inch (6.91).

the block was decked a bit but the stock pushrods seemed to fit fine. the lifters (Mopar Performance) had good alignment.

the engine is from a 1999 Durango. The heads will go in to get checked out Monday.

Thanks for the help from all of you

cam to crank timing chain -way off by last installer!!!!!!!!!!!!!!!!

if the crank is at 12 oclock...and the cam is at 6 oclock and lined up...you are at #6 firing....

if both are at 12 o clock and lined up you are at #1 TDC...

Really?? I'm not an engine builder but the SBC I built, the BBC I built, and the 140 Corvair motor I built are all at 6 & 12

that is not always the case i don't believe. if the crank is at 12 and the cam at 6 you should be correct as the crank turns 2 times to the cams 1 turn. BUT you can also set both at 12. still the same outcome. just turn the crank over 1 full turn till they are at 6 and 12. i know some older books say to line them up 12 crank and 6 cam and that will put the distributer a half turn off. just how the cam is ground and thats all.
as for what happened to your pushrods my thought is the lifters were loaded solid (OIL) and did not bleed off or you have a serious valve spring coil bind issue of the cylnder heads. that is a lift of cam and rocker ratio issue. let us know what you find......

scroll down - its a visual thing 4 ya


http://www.pavementsucks.com/tech-article-37.html

just make sure u have #1 piston & tdc!! and align all gears & chain up.

dix wrote:the new hemi is 12 oclock and about 2:15 or 2:30 on the cam

the 5.7 hemi is a different beast altogether dix. i think they have multiple chains up front. but a 99 durango used the 318 or 360 block similar to the early design small blocks. timing is the same as the older versions.
now if they used a multipe keyway lower gear you can run into trouble there for sure.........

Unless you are installing a cam into an already assembled engine, you first find TDC#1 on the crank. This can be TDC#1 OR TDC#6, until you install the cam.
Once the cam is installed (almost always 12 and 12 BTW, 12 and 6 is usually TDC#6) at TDC#1, the 2 lifters, pushrods and rocker arms will be at base circle and the 2 cam lobes will be pointing away from the lifters. The 2 lobes for #6 will be up at the lifters and the lifters, pushrods, rocker arms and valves will be in Overlap position; exhaust closing and intake opening.
Very easy to ID with the intake off.

Yup twin. that's what mine looks like. 6 & 12. I don't know how those hemi people do it. the closest thing I have in my memory is helping a buddy replace a head gasket in his older than dirt International on the side of the freeway. Dirty, lotsa gasket material left on the block & head, duct taped the hell outta the rad hose on off we go. all he said was "It'll make it"

the machine shop said it had 1 bent valve. Intake on number 3. That's being fixed. Gotta find my degree wheel again and try to hook that thing up to see it the lobes are opening when they should.

To close this out, I replaced the valve and spun the engine around a couple of times. No contact between the pistons & valves. I'm thinking it must have been weak pushrods. Went through all my receipts and couldn't find any for new pushrods. They gotta be the originals and not up to snuff for the new valve springs. We will see...