Oh, another thing I wanted to ask about installing a camshaft, since I've never done it. Do I need a camshaft degree wheel? Or can I set the crankshaft to TDC remove the timing gears/chain, install new cam, and install new timing gears/chain? Would the key way line up from the old cam to the new one, as far as valvetrain events occurring at the proper time?

 

It's actually pretty simple, the sprockets both have keyways and both have dots on them. You put the sprokets on the keyways and rotate them until the dots line up then remove and reinstall the sprockets with the chain. The dots are either lined up right or its off a link (bad) and the dots won't be quite pointing at each other, so you do it again until you get it right.

I'd go as far to say that 99% of 3800 cam installs are done like that.

Only way I'd even consider a degree wheel for install is if you've got an adjustable timing chain set (has multiple offset keyways to advance or retard the cam). If you degree the cam without one and find out the cam is ground a few degrees off (not particularly uncommon), what are you going to do about it as it only goes on one way? If you've got an adjustsble timing set, you can correct it to get it perfect.

IMO for a max effort setup, I'd certainly take the extra time and money to degree it. For about anything else, I'd just slap it in and line the dots up.

 

That's what I figured. I didn't know it was somewhat common for cams to be ground off a few degrees. In that case, I'll definitely go ahead and pick up summit racing's degree wheel kit when I go to install the cam. The double roller timing chain has multiple keyways on the crank sprocket, so I can adjust if needed. Speaking of that crank sprocket, I know it is supposed to be a super tight fit. I've read some people have it machined, but others have just hammered it on using the old sprocket. I don't plan on ever removing the new sprocket once the cam is degreed, so would it be fine to just hammer it on there with some silicone grease or anti seize?

 

I probably should note, that comment is based on LS cams and the quality does vary by manufacturer. Not that 3800 cams are any different, i just don't know how common it is on this platform (likely because most just do the dot to dot).

Ultimately there's very little impact of it being a little off for the average joe unless its got ultra tight PTV or is an all out build.

If you're getting a Rollmaster keep in mind the chamfer issue. There is a known interference issue between the back of the sprocket not matching up to the US crank snout radius causing the crank sprocket not to seat all the way. It needs some light machining to correct to make sure the chain isn't riding at an angle and eating itself.

In terms of hammering the sprocket on, I wouldn't. You'll never see a pro engine shop beating on something with a hammer to make it fit. Its one thing to tap something into place to overcome a light drag but if its so extreme of an interference that you're literally hammering it like a nail, then its not right. Id try using either heat or cool (in moderation of course, not talking about getting it cherry red) depending which part you're applying it to to dimensionally change it slightly to allow it to go on.

My concern with legimtiate hammering is inducing stress or causing a dimensional change in the sprocket. Even if you never plan to remove it, the last thing you want is that sprocket coming apart or wearing at the chain. Just my .02

 

Oh, okay. I misunderstood where that sprocket needed to be machined. I thought it needed to be opened up on the inside, where it slides onto the crank. Is that an issue with just the Rollermaster brand chain set that ZZP sells, or is that also an issue with Intense Racing's brand of chain?

JP Double Roller Timing Chain

 

So the theory is that since the chains originated from Australia that they were designed around the Australian 3800 crank snout which has a slightly different chamfer transitioning to the snout (smaller chamfer/ less meat).

Apparently the US cranks had more meat in this area, but of course tolerance varies one crank to the next. So some people have little to no issue, but most have some kind of interference. The worst case I saw online literally broke the crank gear as it was riding so far off. The typical problem is chewing up the chain super quick because it doesn't run parallel to the block with the crank gear not seating all the way.

I don't recall how it went down, but I want to say either JP bought Rollmaster or the other way. I believe there have been issues with both.

Here is a guy showing a machined version of each next to stock:

Machining double roller crank gears (pics + vid)


I'm sure youre already aware, but you know you've got to machine the oil pump cover as well, right?

 

Okay, that clears up all my confusion. I'll definitely go back to the machine shop that I had do my flexplate machining and have them chamfer that sprocket.

I had planned on getting ZZP's oil pump kit, which comes with a machined oil pump cover

 

One more question. I know that with a bigger cam and heavier valve springs, certain components will wear faster and need to be replaced. I was curious as to exactly which parts, and roughly how many miles/drag strip passes are recommended until replacement?

 

I wouldn't worry about it at all.

Its certainly not a myth that harsh hard-core race valve train parts wear items more quickly. But the stuff you're going to be running, while on the bigger end for a 3800, is very tame in terms of the hardcore race stuff where it is a real concern.

The cam for example compared to the specs of a race cam for a LS or BBC is much more mild in terms of lift and ramp rates. The springs are the same - I'd imagine you'll put something like 130s on it. Figure a stock LS7 runs a bit over 100 in a factory reliable engine. Hard core race LS springs can get up into the mid 200s (with 800+ open force).


The two things I'd consider:
-Valve springs will lose force over use. Depending how close you are to floating the valvetrain (Rpm and spring rate), as the springs lose ability, you may start to see float where you didn't have it before. This wouldn't happen quickly though, I'd bet it would take thousands of miles to even get a perceptible reading change on a tester, much less degrade so far as to cause issues. You could always just wait until you see signs of float and dial back the shift points a couple hundred rpm or just swap the springs. Its not catastrophic.

-Timing chain will stretch over time. With no tensioner, you will get slack. I've never seen one get so slack it skips a tooth, but I have seen some get concerningly loose with higher mileage. Maybe worth taking a peek at 30-50k or something? Of course that's assuming you've got the chain dead parallel to the block otherwise it will wear out much sooner from eating itself.

-The one big thing is to make sure you don't open up the valve seats too far for bigger valves that you remove the factory hardened seats in the heads. Intense did this way back in the day on their heads and as a result the valves would eat their way into the heads fairly quickly over time.


The thing is that although wear certainly increases everywhere in the valvetrain, the factory valvetrain goes for hundreds of thousands of miles. Even when some 3800s start failing in the mid 200k miles, its not valvetrains wearing out. So even if you cut that life down to 200k or even 150k, it won't really matter as youll probably blow it up well before then anyways if you're really racing it.


TBH it isn't particularly common to get that high of mileage on high hp 3800s. Either people really race it and break enough stuff that they get out of the platform. Or they rarely do serious track racing and mostly just street drive it - where it doesn't hook (due to street tires), gets miserable gas mileage, and breaks down periodically (due to all the aftermarket parts) - so its generally a 2nd or 3rd etc car that isn't racking up DD miles.

 

That's good to hear. I was planning on using 150lbs manly springs, 3/8th pushrods, and a double roller timing chain with a tensioner if I can reuse the old tensioner. I know it's not exactly necessary when he chain is new, but I'd like to have it for when the chain starts to stretch.