Jump to content

3800 Rebuild


karrkrazzie

Recommended Posts

How hard is it to replace all of the gaskets on my 3800? I am thinkin from the block up. Car has 140xxx on it, and it is smellin offly sweet when I get on that gas peddle, however no milky oil. so idk if the head gaskets are bad or what. just think this wouldnt hurt. Also what else would I need to do, or would it be smart to do while it is all apart?

Link to comment
Share on other sites

How hard is it to replace all of the gaskets on my 3800? I am thinkin from the block up. Car has 140xxx on it, and it is smellin offly sweet when I get on that gas peddle, however no milky oil. so idk if the head gaskets are bad or what. just think this wouldnt hurt. Also what else would I need to do, or would it be smart to do while it is all apart?

 

You may need to replace the upper intake plenum and LIM gaskets... The plenum should have a date stamped onto it (the little circles with arrows pointing at numbers)... If its original, it will have a date of 98 or 99 on it... Since they were made of plastic, and the EGR stovepipe was too large, the plenums would warp and suck coolant into the motor... If you decide to replace gaskets though, they are pretty easy on this motor compared to the 3x00 motors...

Link to comment
Share on other sites

I am not sure yet, just looking for some input. The kit from autozone is like 180 I think... So I am not sure yet. I dont know which one I have l36? maybe.... But isnt there a better/newer 3800 that I can swap out the top half of mine with to gain some extra power? and how much extra power would it be?

Link to comment
Share on other sites

I am not sure yet, just looking for some input. The kit from autozone is like 180 I think... So I am not sure yet. I dont know which one I have l36? maybe.... But isnt there a better/newer 3800 that I can swap out the top half of mine with to gain some extra power? and how much extra power would it be?

 

Your best option would be to swap the top end of a L67 over onto your L36... IIRC, it would involve doing some wiring, but it would be the best bang for your buck, IMHO...

Link to comment
Share on other sites

good to know, ill be keeping it in mind.... I wonder how much it would cost to use new parts... Do you swap the heads out too? or just most of the other stuff

Link to comment
Share on other sites

good to know, ill be keeping it in mind.... I wonder how much it would cost to use new parts... Do you swap the heads out too? or just most of the other stuff

 

You have to swap the whole top end over (heads and all)... The heads in the NA 3800 aren't as strong as the heads in the SC 3800 (l67)... I do believe though that there is an advantage to using supercharger on the NA block though compared to the L67 block... I don't remember if the internals are stronger, or if the compression ratio is different or what, but there is some advantage...

 

And I would probably just try to find a low mileage junk yard L67 top end and do the swap with that... It'll save you a lot of $...

Link to comment
Share on other sites

what kind of power can you get out of these.... I may do everything while I am in there.... roller rockers, camshaft, high performance injectors, doing this, could i get the car up over 300hp?

Link to comment
Share on other sites

Well lets see what you're looking to do first. From the first post you seemed like you're just looking to put new gaskets in, but later on you seemed interested in the top swap haha. ZZP and a few other companies(I can't remember off the top of my head) make a re-inforced stronger upper intake plenum for the L36's that won't warp/melt like the factory ones do. They don't increase performance at all, just peace of mind that all that crap won't happen again.

 

But if you do want the L67 top end, you'd need quite a few things. Blower, LIM, heads, injectors/fuel rails, harmonic balancer, bolts etc. along with a few other things I cannot seem to remember.

 

But the advantages of using the L36 bottom end is indeed higher compression. The L36 has 9.4:1 I believe, where as the L67 has 8.5 or 8.8?

Link to comment
Share on other sites

when it comes down to it... idk what the fuck I wanna do.... i want a sleeper. I wanna make the motor as quick as possible w/o a supercharger or turbo. So my thought was... while it is all apart and I am doing the gaskets, then I might as well just do what i wanna do. So keep the l36 block... swap out for the top of an l67, install performance cam, roller rockers, high performance injectors, new lifters, pushrods. Really just curious if it is even worth the money. I figure on spending about 1500 - 2000 and get it up to at least 300Hp. is that accurate?

 

 

Link to comment
Share on other sites

i would buy the N/A 3800 top end kit from napa auto or advanced or where ever. they have an updated egr valve tube that will keep it from sucking coolant where it shouldnt be. so if you wanna just get it running right, do that. otherwise, drop some $$$ and get the zzp kit.

Link to comment
Share on other sites

When you do the lower intake gaskets, order the updated GM Aluminum framed lIM gaskets. they are better than the stoch and felpro ones, and I believe cost the same.

Link to comment
Share on other sites

I seem to remember that you could swap the upper intake plenum for the solid aluminum ones used in the later years for not much trouble. It was on either 3800pro or clubgp, (thinking it was clubgp) there was a nice write-up.

 

What gains would a L67 top end have if he doesn't want a blower? I thought the supercharger was the only point of a L67 top-end?

Link to comment
Share on other sites

The supercharger is the only point of the L67 top end swap.

 

The Aluminum L26 upper intake will swap, but you'll still need to get an adapter for the TB as the newer ones are drive-by-wire and not cable if I remember right. There is a little more involved than a straight swap, but nor quite as much as a L67 swap.

Link to comment
Share on other sites

The supercharger is the only point of the L67 top end swap.

 

The Aluminum L26 upper intake will swap, but you'll still need to get an adapter for the TB as the newer ones are drive-by-wire and not cable if I remember right. There is a little more involved than a straight swap, but nor quite as much as a L67 swap.

That sounds right, I seem to remember him saying you needed a TB adapter plate, but its a better Upper Intake all around

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...