magnum swap questions

NyNeon0813 · Post by **NyNeon0813** » Wed Feb 22, 2012 6:48 pm

so i finally started my swap. but have a few questions before i continue. 1. the timing belt tensioner on there right now is the hydraulic tensioner, but the one that i bought is the mechanical tensioner.. can i just switch them?

couple random pics

2. my timing belt seemed to be somewhat pinched under the crankshaft, and on the inside of the timing belt, there was a line from where it was being worn down.. is this normal?

Post by **occasional demons** » Wed Feb 22, 2012 9:34 pm

The mechanical tensioner will bolt on. You will need to remove the back timing cover and punch a hole in it. Or remove enough so the tensioner does not clamp down on the cover.

Donkeypuncher wrote: From the timing belt how to, he mentions trimming the cover at the bottom http://chronoscender.freeservers.com/ne ... gbelt.html

viewtopic.php?t=60214

Was there debris, or something stuck at the bottom where the belt squeezes through there? That isn't terrible, but it isn't normal either.

NyNeon0813 · Post by **NyNeon0813** » Wed Feb 22, 2012 10:26 pm

nothing was stuck in there that i saw, it just seemed like the gap between the crankshaft sprocket and engine is just too tight. could the sprocket be pushed in too far??

and another thing is i broke the outside timing cover getting that stupid motor mount plate out. how big of a deal is that? i planned on cutting the top of the timing covers anyways so i can adjust the cam gear later on

Post by **occasional demons** » Wed Feb 22, 2012 10:43 pm

The sprocket could be pushed in too far, but you oil pump would be damaged. The cut edge of the belt would be wearing, not the outer edge.

The aluminum casting from the oil pump might be too tight to the crank sprocket. You would need to pull the sprocket, and dremel the casting to give it some clearance, then reinstall the sprocket. There is a special tool you need to keep from pushing it on too far.

The outer cover, depends on how bad it is broken. You don't want road debris getting in there. No cover would be almost better, at least if something got caught, it would have a chance to be spit out. Not recycled, bouncing around in there. Some permatex plastic weld would glue it back together.

INVUJerry · Post by **INVUJerry** » Wed Feb 22, 2012 11:12 pm

I'd run the old hydraulic tensioner with a new bearing from the dealer.

NyNeon0813 · Post by **NyNeon0813** » Wed Feb 22, 2012 11:48 pm

What would be the easiest way to get the sprocket off?

Jerry, why do u say to stick with the old kind of tensioner?

Post by **occasional demons** » Thu Feb 23, 2012 7:08 am

You need a puller. IIRC there are two threaded holes in it.

FWIW, I know my hydro tensioner was toast at 112,000 miles. You need to compress it and put a pin in the two holes to re install the belt. Mine would not compress. Not even in a vise.

NyNeon0813 · Post by **NyNeon0813** » Thu Feb 23, 2012 8:24 am

So of I was to just pull the crankshaft sprocket out a little bit, would that help u think?

And another question, unlike the non mag header, the rt header does not have spot for the o2 sensor and the direct fit magnaflow cat I got only has the spot for the downstream o2 sensor. So what is the best solution?

Post by **occasional demons** » Thu Feb 23, 2012 12:36 pm

I doubt pulling the sproket out will help. whatever extra it is out, the belt pulley will shove it back.

A bung can be welded into the header, or the cat. About the only two options. The R/T header I got had the bung welded in by a PO.

NyNeon0813 · Post by **NyNeon0813** » Thu Feb 23, 2012 1:37 pm

So would I be sleight if I just left the sprocket as is?

Post by **occasional demons** » Thu Feb 23, 2012 1:42 pm

NyNeon0813 wrote: sleight

.
?

I don't think the old belt was worn enough to really effect it, how many miles did have on it, and hadn't failed.

Maybe take a flash light and see how close things are in there with the belt on.

NyNeon0813 · Post by **NyNeon0813** » Thu Feb 23, 2012 2:34 pm

"Sleight" was supposed to say alright lol. Stupid swype text.

The timing belt was put on only a couple months ago when my water pump went

NyNeon0813 · Post by **NyNeon0813** » Thu Feb 23, 2012 4:44 pm

What size nut would I need to weld on for the o2 sensor. Talked to the maintenance guy at my job n he said he would do it

Danteneon · Post by **Danteneon** » Thu Feb 23, 2012 5:33 pm

You will want to have a O2 bung welded in, not a nut.

Some autopart stores carry them, but you can get them from Summit, Jegs, Amazon, etc.

NyNeon0813 · Post by **NyNeon0813** » Thu Feb 23, 2012 5:41 pm

Cool thanks

NyNeon0813 · Post by **NyNeon0813** » Fri Feb 24, 2012 4:36 pm

So when I put the new head on, all I have to do is set the new cam gear up with the timing mark from the old head?

Post by **occasional demons** » Fri Feb 24, 2012 7:41 pm

Just set the gear to zero, Rotate the mark to the top, as close as you can get it. Be sure the crank is still at TDC. Then install the head.

gcretro · Post by **gcretro** » Sun Feb 26, 2012 12:11 am

occasional demons wrote: The outer cover, depends on how bad it is broken. You don't want road debris getting in there. No cover would be almost better, at least if something got caught, it would have a chance to be spit out. Not recycled, bouncing around in there. Some permatex plastic weld would glue it back together.

About that cover, although my cover is not broken, I'd lke the top half to be removable/open-able. It only has a small hole with a cap but can't check anything from that.

Figured i could cut the top part to make a removable cover. but then have to find a way to securely hold it in place too... Any ideas?

INVUJerry · Post by **INVUJerry** » Sun Feb 26, 2012 7:10 am

Just cut the top off the outer cover. It's not needed and up that high doesn't do anything.

As Bill said, get the timing mark to 0 on the crank. On the head if you were to hold it parallel from the ground the cam pin should be pointed straight down.