I'm swapping in an L67 from a '99 Regal w/ 4t65ehd. Car will still be a daily driver, but I'd like to find some horsepower where I can for the occasional track day. I just spoke to a shop about getting the heads done and they said they really didn't see any need for it if the engine was going to be in mostly stock trim. At most, I'm thinking about doing the N* TB, 3.4 pulley and some head work (port match, polish). Would I still see any significant gain from the port & polish if I'm not going with an aftermarket cam & etc? Or should I just skip the TB, pulley & head work... keep the motor stock if I'm not talking about going the whole nine yards?

[This message has been edited by MickeyAsh (edited 07-16-2009).]

No need for head work with what your going to do. I'd recommend the 1.9 rockers though. Money well spent for the 3800sc.

Do rockers or cam, then exhaust before you do heads. You will see more gain for the money with these. There are guys putting down 400whp on stock head turbo 3800's.

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'84 3800SC, XP cam, 3.2 pully, HPTuners, N* TB, 4sp, SPEC 3+ clutch, Aluminium flywheel, pacesetter headers, F355 body kit, weight reduction

I'm still looking for the car to be reliable as a daily driver. I'd say that's essentially a top priority.

@Lambo; these, or is there something better? http://www.zzperformance.co...php?id=426&catid=104

@Dracor: What kind of cam can I look at while keeping the reliability up?

[This message has been edited by MickeyAsh (edited 07-16-2009).]

Yes, those. And you will have no reliability issues after installing them.

Also, you either do a cam or the rockers, not both. They both accomplish basically them same goal, so it's redundant to do both.

[This message has been edited by LAMBO (edited 07-16-2009).]

quote Originally posted by LAMBO: Also, you either do a cam or the rockers, not both. They both accomplish basically them same goal, so it's redundant to do both.

And this is why we ask questions! Haha. Okay, so I take it you'd recommend doing the rockers instead of the cam? Or is it really a matter of preference? Again, reliability being top priority...

[This message has been edited by MickeyAsh (edited 07-16-2009).]

quote Originally posted by MickeyAsh: And this is why we ask questions! Haha. Okay, so I take it you'd recommend doing the rockers instead of the cam? Or is it really a matter of preference? Again, reliability being top priority...

Go with rockers, less parts to change, less things to do wrong, and its pretty easy to do. All you need tool wise are a few sockets and a torque wrench. Many people upgrade the valve springs while they are in there, since its just slightly more work. With just rockers you could go with something a little less than the 105# ones commonly sold.

Yes, a matter of preference. Rockers are wayyy easier. But a cam gives you choices, and there's always that lopety lope sound you can get with a cam.

quote Originally posted by Dracor: Go with rockers, less parts to change, less things to do wrong, and its pretty easy to do. All you need tool wise are a few sockets and a torque wrench. Many people upgrade the valve springs while they are in there, since its just slightly more work. With just rockers you could go with something a little less than the 105# ones commonly sold.

Any specific recommendation on springs?

I would only consider the 105 springs if the motor I was swapping in is higher mileage (weakended stock springs). Otherwise, based on the mods your talking, there is no need for them (based on my own experience). Valve float hasn't been an issue for me.

Motor is approx. 80k, I believe. Think I should do the 105s?

Edit: If yes, are these okay? http://www.zzperformance.co...php?id=113&catid=104
Edit: On that product I keep seeing "1.80 recommended install height". What do I need to know about that?

[This message has been edited by MickeyAsh (edited 07-16-2009).]

Are you going to primarily race, or use as a daily driver with the occasional blast?
If race, then yes.
If daily drive, then no.

The mileage threshold for me is 100k on springs, to more specifically answer your question.

Edit: What kind of difference is there between 1.84's and 1.9's? If I go with the 1.84's is there any problem with doing the #105 springs?

[This message has been edited by MickeyAsh (edited 07-16-2009).]

stock heads have been proven to make upwards of the 800HP areas, so I dont see a need.

As far as springs go.... you are pretty much screwed... so I stay with stock springs on all of my cars unless I can get ahold of a rollmaster timing chain.

Sorry, left work, now I'm home. In continuation, here is a very good article that'll explain what's going on better than I can.

http://www.boyleworks.com/t.../psp/RockerArms.html

Also, if you were to grind the valve seat and valve face, the valve spring installed height will be increased a corresponding amount. The use of different retainers/rotators as well as valves with different keeper heights will also effect the valve spring installed height. Valve springs are designed to provide a specified pressure at a given installed height (in this case 105# @ 1.80). When this height is altered due to the valve grinding process, the springs will no longer provide the proper tension. Thus limiting the engine rpm capability. I believe a stock, virgin L67 head would give you this installed height. If you did a valve job on the heads, you'd need to grind (shorten) the stem to get back to the recommended installed height. Hope this made sense.

I have 105#'s and stock timing setup on mine, but it is a race only setup. By the time the tensioner would need replacing, I will most likely not have the car anymore.

Here is a link on some discussion on springs and 1.9 rockers CGP link

And another one

It looks like people have had success with L76 springs for 1.9 rockers, pretty cheap too. Some have had valve float with just rockers and some have not. It will just be a crapshoot.

So using 1.84 rockers instead of 1.9's just mean that there'll be a little less stress on the valvetrain, and the valves will be open for a little less time than the 1.9's, right?

Yes

quote Originally posted by MickeyAsh: So using 1.84 rockers instead of 1.9's just mean that there'll be a little less stress on the valvetrain, and the valves will be open for a little less time than the 1.9's, right?

Technically, the duration remains the same. The 1.84 have slightly less LIFT (how far the valve goes into the cylinder). Which equates to less valve guide wear, less stress on the timing chain and tensioner, less air flow and less chance of valve float.

quote Originally posted by Dracor: Technically, the duration remains the same. The 1.84 have slightly less LIFT (how far the valve goes into the cylinder). Which equates to less valve guide wear, less stress on the timing chain and tensioner, less air flow and less chance of valve float.

Reading that, it almost sounds like I have LESS chance of needing the #105 springs if I'm going with the 1.84's.

quote Originally posted by MickeyAsh: Reading that, it almost sounds like I have LESS chance of needing the #105 springs if I'm going with the 1.84's.

Correct. Honestly on a low power build, you would prolly be fine with stock or L76 springs, plenty of people have had no problem with the stockers on 1.9's.
You could always just try it, then if you get float, upgrade the springs.

The higher the boost you run and your redline determine if you need stronger springs.

Okay. Went with 1.84 rockers and I'm going to stick with the stock springs for the moment. Now, the pushrods that came with the Yella Terra rockers are approximately 3cm longer than my old pushrods. Do I need to do anything to the rest of the valvetrain to adjust for the increased pushrod length?

[This message has been edited by MickeyAsh (edited 07-18-2009).]

quote Originally posted by MickeyAsh: Okay. Went with 1.84 rockers and I'm going to stick with the stock springs for the moment. Now, the pushrods that came with the Yella Terra rockers are approximately 3cm longer than my old pushrods. Do I need to do anything to the rest of the valvetrain to adjust for the increased pushrod length?

they are 3 cm longer? 1.84 rockers change the pivot point THAT much?

[This message has been edited by stickpony (edited 07-19-2009).]

quote Originally posted by stickpony: they are 3 cm longer? 1.84 rockers change the pivot point THAT much?

http://i246.photobucket.com...keyash2/CIMG2732.jpg

Bump. Anyone got thoughts on the pushrod length?

I think i did the math on the 1.8 YT rockers and pushrods I have.... the net length resulted in a shorter than stock pushrod length, and I do not even pretend to float my valves with my 400+whp turbo setup.

[This message has been edited by darkhorizon (edited 07-20-2009).]