Cam install do you have to remove intakes?

[ssms5411]

Talking with my mechanic today does the intakes need to come off on a cam install? I thought you could just pull the valve covers, its been awhile and my memory isn't great, hes going to be doing my cam and double roller timing chain. I have new comp oer lifter. To go in but the comp oer lifters that are in there barely have 50k miles on them. So if i can i like to keep them. He says you have to pull the intakes and valve covers.thanks for any help.

[LETZRIDE]

Yes upper and lower intake must come off, and if leaving the heads on you have to use an air compressor with a special fitting inside each sparkplug hole to keep the valves open.

front cover also has to come off, radiator can stay in, I believe you need to snip a fan shroud piece if you leave the fans on.

[LETZRIDE]

Make sure he “blues” the timing chain to ensure it is installed flat- the double rollers have a chamfer designed for the aussie 3800’s and it is a slight different angle than the American version of the motor. This causes the chain to slighly cockeye and was the reason why guys were overloading one chain in the double roller and breaking them.

you may need to pop the sprocket that goes on the crank on a lathe to correct the chamfer angle

[FirebirdGT]

Talking with my mechanic today does the intakes need to come off on a cam install? I thought you could just pull the valve covers, its been awhile and my memory isn't great, hes going to be doing my cam and double roller timing chain. I have new comp oer lifter. To go in but the comp oer lifters that are in there barely have 50k miles on them. So if i can i like to keep them. He says you have to pull the intakes and valve covers.thanks for any help.

Emailed you the GM Service Manual -3800 Engine section - hope your email accepts it.

[ssms5411]

Got it, thanks.

[ssms5411]

Damm, I was hoping I could do it with the intakes on, oh well looks like ill use the new comp oer lifters after all. I think ill wait a bit and do the alm. heads from zzp as well. Probably be next year, zzp has them out of stock, and when i email them they always say 2 weeks but that was like 2 months ago.lol

[ssms5411]

Make sure he “blues” the timing chain to ensure it is installed flat- the double rollers have a chamfer designed for the aussie 3800’s and it is a slight different angle than the American version of the motor. This causes the chain to slighly cockeye and was the reason why guys were overloading one chain in the double roller and breaking them.

you may need to pop the sprocket that goes on the crank on a lathe to correct the chamfer angle

Mike I emailed ZZp and they said the double roller is a tight fit and nothing needs to be done with it. Just a tight fit and that was all. Ive read some threads where people modify it in some ways so I dont understand.

[LETZRIDE]

I highly doubt any of the vendors ever fixed the issue to be honest Steve because it wasn't a well known issue, what was well known is the chains would overload, stretch and break. I can't find the photo I have of the back of the sprocket but I dug up these photos of when I yanked the motor. I added an arrow to it to show you the piece I am talking about....if you look at the back of this piece which is from the double roller timing chain and compare it to the stock piece you will notice the angle of the chamfer is slightly different on them. All you need to do is take the old piece and the one from the double roller timing chain to a machine shop and tell them to match the chamfer of the stock piece - it will take them literally 15 minutes on a lathe. If you do not correct this issue you'll risk overloading and breaking your timing chain as so many members have done in the past. It will look like it is tight to the block, but it is thousands of an inch off and it is enough that it cockeyes the chain just enough that more stress is put on one chain causing failure.

If you had machinist blue paint and put it on the double roller timing chain as it comes from any of the vendors and install it on the block fully, then pull it off to remove it - you'll see based on the paint pattern it isn't sitting properly





This is a shot showing you where that piece slides onto....see that ridged area? If the taper angle on your sprocket it off it won't sit right. Like I said, show a machinist the piece from the double roller and your stock piece and tell him you need the chamfer to be the same as stock for the new piece... he'll know exactly what to do.

[ssms5411]

Thanks Mike, I guess I shouldn't take the word of a vendor, ill let my mechanic know when he does the work. Now it wont be until next year, I hope my single holds up another year.

[ssms5411]

Was thinking it over and have decided to go ahead and do the double roller this year and then do the cam and alm. heads next year. Better to be safe then blow the engine up.