I'm reading that all V6 Magnums came with a timing chain tensioner from the factory and that the V8s could all benefit from the tensioner - both improving timing a teeny bit and making the engine quieter (both perks I like). While I have it apart I'm considering removing the two factory-installed 19/32 lifter valley plugs and replacing them with two fresh ones each with a 1/64" hole in them (and a corresponding port in the tensioner plate) to allow pressurized oil to squirt out onto the cam gear, and then slung out into the t-chain. The tensioner assembly has the drain tab for dripping oil I presume from the front cam bearing, but that doesn't seem like a 'lot', and I'd like a bit more on the chain.

I've also read that two such small holes in the lifter galley plugs will have a negligible effect on overall oil pressure.

Also, I've read that the tensioner isn't specifically 'compatible' with a double roller chain, so I'm going to go back to a stock-style Cloyes single roller/stock chain and saving the double roller I have now for a warm 318 going in the Demon...maybe - might install a regular single-roller timing set like this in that too - this set -



The thrust plate in my Mag 360 looks like this, but the d-side drain passage is useless with the galley's plugged, and the tensioner is too, so I might as well take advantage of extra oiling via the plugs, ja?



Reasonable mod, or not good?

Appreciate the inputs or recommendations, and thanks in advance.
- Sam

I want to say people have put those magnum style tensioners on LA engines with double roller race type chains? Check with Mancini and see if they have ones that are compatible with a double roller?

Mancini actually didn't have much knowledge about them - nothing fresh to add other than 'they sell them', but according to lots of searches the tensioners are unanimously good with a stock single roller t-chain, and most are good with a double, some had bad results with shredded guide(s), which is why I'm going to run a single.

But my main question is about drilling small holes in the oil galley plugs to squirt oil onto the gear/chain.

your taking oil from the mains and rods to oil a timing chain....no to good in my opinion.

And i can't see any real benefit to the chain.

Exactly. Good double roller timing chains last a really long time without tensioners or extra oil.

You could grind bevels in the holes in the timing gear so it acts like a fan pulling oil and air from under the intake if you want more oil in the timing cover.

The tensioner works...with a real double roller timing chain. No problems ever. Real experience,not something i read somewhere. More than several engines, 2 got wrung out on the road course. The roundy rounders have been using it for a long time. We always added the 4th hole and used a bolt with the hole in it for oil. If one is really worried about the oil on the chain put a bypass oil cooler like on a cop car as it feeds pressurized oil to the chain via the return at the fuel pump

Same here.

I've been using this approach (including the 4th oil feed hole) with my Sealed Power 220-3103 chain, which is a double roller.

No issues installing, no noticable wear on the plastic support either.

Here is another thread on the same topic => Timing Chain Tensioner: Yay or Nay?

haven't seen about the '4th bolt' - have a link?

my '02 Magnum 360 doesn't have 4 bolts holding the thrust plate, so not sure which '4th bolt' y'all are referring to - here is how mine looks -



I think I'll run the tensioner and silent chain, which for my stock truck engine should work real good. Not sure about parasitic oil pressure losses so may just rely on the dripper and oil slinger. Not sold on drilling a hole in the p-side upper bolt - if it's just a 'drain' then there won't be much coming out of it, especially considering the steep downhill angles this engine will see will send quarts of oil towards the front of the engine, which should pretty adequately oil the chain, flood it is more like it.

ok - decided on the tensioner setup & OE single-row silent t-chain kit, 1/16" ported lifter valley plug, and an oil slinger, all of which should lubricate the chain whether I'm aiming up or down, and protect the front seal from the rush of hot oil when aiming downhill, and keep the timing nice and crisp...all the time, especially at idle. My original cam thrust plate has a small recess on the back side which by all accounts appears to have bene originally developed by the Chrysler engineers to provide additional oil to the chain (with the lifter valley plug not in place)...but some models don't have that recess...nor valley plugs...but at some point they were designed for such, and all models have the thrust plate which completely caps off both lifter valleys, so I figured a tiny 1/16" hole in the d-side plug won't result in any appreciable loss to oil pressure (and several posts on the internet concur), so there it is.

This engine isn't a high-revving power beast, it's just a nice simple low-rpm grunt engine, so I don't remotely need a double roller chain, and since the tensioner setup is intended to be used with a single roller/silent chain that was a natural fit. Many many folks have used the double rollers with no problems (but some have), but as I didn't 'need' one I opted to go with the OE setup, and I'm certain it'll be perfect for my application.

Here's the overall setup, timing dots aiming at each other, all hardware installed, and Joe Gibbs Driven engine assembly grease 'everywhere'; getting the cam gear on the shaft was fun, but 'leaning' into the chain against the spring-loaded tensioner guide pad with the rubber end of a hammer worked great.


This should now be as quiet and crisp of a setup as I can imagine. Now I can finally move on to installing the rest of the valve train, getting the pushrod lengths just right (planning to re-use the OE pushrods). Then I'll polish the wear marks on the rear main with 400 grit, then 1000 grit, install a fresh rear main seal, then button it all up, and drop it back in.

I am however going to also bolt in a new HV oil pump just for good measure, especially considering this engine will be idling a LOT of its life. This engine isn't new - has about 135,000 miles on it, so a new oil pump wouldn't hurt, and I think a HV unit will be beneficial considering the mileage, and it'll never see north of 4500 rpm (at least not intentionally). I'd be happy to see a bit more hot idle oil pressure on the gauge.

Here's the itty bitty dedicated/constant oil squirter direct onto the back side of the cam gear, which being on the 'downhill' side of rotation should sling oil right down onto the crank gear -

I tore apart a LA small block back in the 80's that had one of these with a double roller. The plastic worn to the point the chain was hitting the metal under it(groves worn in the metal). No telling how many miles were on it. After I seen this I decided not to use a tensioner.

Do you recall what the shape of the links on that chain was? Were they straight on the sides, or dogbone shaped? I fell like that could be the difference.

Many more went 200,000-300,000 miles without one on a routine basis. I'm not gonna say they are failure prone or anything just not nessacary and that's backed up by millions of stock chains lasting extremely long lifes. I been working on small blocks over 40 years now and have to replace far more timing covers for leaks more often than chains. Your just fixing something that is not even a problem.

Agree and possibly creating one by reducing the amount of oil to the rods and mains on an engine that does not have a priority main galley.

all good inputs. The vast majority (if not all) of the folks who have installed the tensioner on their 318 or 360 have reported no difference in oil pressure, along with tighter timing, quieter operation, and most were using the single-row 'silent' chain like I not am, and most reported no damage to the tensioner pads over the long term, including most of those with double rollers. Meh - I'll run it.

I am wondering about the utility of using a HV oil pump tho. The main reason I'm thinking about running one is to bump up my hot/idle oil pressure, even just a little (and yah I'm sure a HV pump would more than account for the plug hole I now have, but again I'm not worried about that). My oil pressure isn't 'bad', but with 135,000 miles on it the engine isn't new either, and I wouldn't mind a bit more psi at idle. Anyone know if a HV pump would accomplish that?, and/or if a HV pump would induce some unforeseen side effects I might not want to deal with? Again, haven't found definitive intel to support either a bump in idle oil pressure or 'side effects'...

- Sam

with that hole in the cup plug I think a hv oump is a good idea.

A hv pump can interfere with some pans, might need a doink or two.

I'm using a Ram/Jeep GC pan so no worries about 'clearance'. Can y'all think of any reason 'not' to run a HV pump? I honestly cannot figure out the specific reason why a HV pump even exists, other than if someone were to really open up their oiling galleys and add extra plumbing - more than the OE spec oil requirements, then a HV unit makes sense. But I also don't want to 'over-stress' the dizzy pump shaft...but that may be a non-issue. Honestly I'm tempted just to bolt one up and see if it works any better - just don't want it to work worse.

Pretty sure I'll just stick with the stock pump and see how things go...

If your clearance is within specs there is no need and there are several things that can happen as a result...

1. They make the oil temp run slightly hotter costing you some of the oil pressure you gained
2. they can put more air in the oil by lowering the level of oil in the pan under driving conditions because it also takes longer for the oil to come back to the pan when your trying to return a higher volume
3. extra oil on the cylinder walls will overwhelm the oil rings control sooner in the engines life span,
4. They cost some HP by raining more oil onto the crank resulting in more windage loss and the extra power it takes to turn a bigger pump... not much but a little so moist of the HP you might gain from running looser clearance is lost turning your high volume pump
5. Your more likely to get air in the oil your feeding to critical bearings.


As you probably guessed I'm not a fan of them in general but the entire engine build should be considered together, I do all my builds with standard pumps and don't have any trouble.

thanks - that is great info and I appreciate it