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Grand Prix Project


RooK
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Some of you old timers might remember me, some might even remember my Grand Prix from an old car thread we did back ages ago. For those that don't, here she is earlier this winter:

gpse.jpg

Well, I had been threatening an engine swap for some time from the stock SE's 3.1 V6 to the supercharged 3.8 in the GTP version. It has come to pass. About a month ago my 3100 blew an intake gasket. Not exactly the cheapest thing to fix, and I had it replaced about 30k miles ago. It's a real problem on those engines. Well, instead of investing money in that, I decided to do the swap. I bought an engine/tranny combo from a guy in Ohio who deals in wrecked W-bodies, along with plans/parts to make it scream. I just got the engine home yesterday and broke into her today. So the following pics will show some of my plans of what is going on.

l67a.jpg

l67b.jpg

l67c.jpg

l67d.jpg

l67e.jpg

header.jpg

link to large image

camspec.jpg

Edited by ZJJ
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(quick, scale down your images before ZJJ or WK come round with a feather duster) :whistle:

It puts me to shame, I can hardy do DIY in the home let alone rip a car apart and mess with the engine, fair play to you sir! :)

Slighty OT :

bought an engine/tranny combo from a guy in Ohio who deals in wrecked W-bodies, along with plans/parts to make it scream. I just got the engine home yesterday and broke into her today.

I will leave it to others to read the alternative version of this quote :rofl:

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(quick, scale down your images before ZJJ or WK come round with a feather duster) :whistle:

Too late!

It puts me to shame, I can hardy do DIY in the home let alone rip a car apart and mess with the engine, fair play to you sir! :)

It's my first time going this deep into an engine, but it's all straight forward for the most part. Just watch your Ps and Qs and use a torque wrench. :thumbsup:

Slighty OT :

bought an engine/tranny combo from a guy in Ohio who deals in wrecked W-bodies, along with plans/parts to make it scream. I just got the engine home yesterday and broke into her today.

I will leave it to others to read the alternative version of this quote :rofl:

Pun not intended. When I read the quote and your comment I couldn't stop laughing. Oops. :rofl:

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For an intake, I normally do not use a torque wrench, but with the plastic carrier/silicone seal type gaskets, it is a must along with using the proper sequence. Same with the blower.

Generally as a rule, when I built engines, I normally only used a torque wrench on just the rods and mains and the head(s). Everything else was with a 3/8's " impact wrench.

What are ya gonna do about the ECM? Have ya got one for a car that came with a blower? Not having the proper electronics in that department may cause it to run funny.

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Well, like most modern engines, the 3800 uses the plastic intake gaskets. I'll just torque 'em and not worry about it. I'm also throwing on new head gaskets just in case, and a good cleaning. Someone didn't care for cleaning under the hood. I think it even had the original plugs in it, the wires sure were. One plus is that is unmolested by mods.

Yep, got the whole wiring harness and pcm. However, the wiring harness is returning for a replacement. It was in bad shape and the guy apologized. It's also going to get a tune of some sort (whether I buy one preprogrammed or buy a programmer myself). I'll also be dropping a few pulley sizes on the blower.

WK, if you can offer any advice, feel free. Anything that makes my life easier or makes sure the engines works is OK in my book. :)

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Be careful with the pushrods, they may be different lengths. IIRC the intake pushrod is longer than the exhaust one. I bent 3 the first time I did a 3.1 with em. The 3800 may be similar.

You could always try to start it sitting on the ground like that, but DIS ignition systems aren't that easy to do that with. Make sure that the crank and cam sensors aren't broke or cracked. They can keep the engine from starting. I don't know what weight oil was used before, but I will tell you this, used what the cap says and nothing else. Engines nowadays have closer tolerences compared to 20+ years ago and need the thinner oil. If it says 5W-30 use it.

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No idea on pushrod length, but I'm going to stick them in order in the side of a box and install them back in the same place they came from. Got the exhaust manifolds and lower intake off today. Now I need a gasket scraper, those paper gaskets are on there good. I'm also having trouble finding the right bolts to pull the harmonic balancer. Apparently GM used 1/4" bolts, so typical kits don't have them. Got some today, but they're too short. Time to try again.

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The inlet pushrods probably will be longer, as WK said. And if you take the valves out of the cylinder head, the inlet valves will probably be larger than the exhaust valves as well, so don't mix them up!

They do that because it's relatively easy to get the combustion gases out of the cylinder, but the real trick to making an engine better is to get high volumetric efficiency - ie to completely fill the cylinder with a fresh charge of air in the intake stroke. Usually you struggle to completely fill the cylinder volume (especially at high revs), which means less air available in the cylinder, which means you have to dial back the fuel as well (which in turn means less power) to maintain the air-fuel ratio mix at the right value because petrol engines need to maintain a stoichiometric mixture to burn (that's around 14.5 air-to-fuel ratio, if you're interested, depending on precisely what grade of petrol you're running).

To avoid the drop in power you need to cram in as much air as you can to allow you to burn more fuel - that's obviously where turbos and superchargers come in, but even without forced-induction like that, naturally aspirated engines do it by making the inlet valves larger and increasing the lift on them to let more air in.

So yeah, when you take it apart, make sure you get the inlets and exhausts the right way round when you put it back together!

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Stuff I already know, but thanks for the reminder. :thumbsup: I've got the heads off and the rockers/pushrods organized for reinstallation. Anyone got tips for removing the last of the MLS gaskets left on the head to prep for the new gasket? A guy at work recommended lacquer thinner, but I'm open to suggestions.

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