Factory Upgrades (and a piece of humble pie)
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From: Hamilton, Ontario
Factory Upgrades (and a piece of humble pie)
Not to beat a dead horse, but the time has come for me. My engine is out and its going back together soon. My goal is to gain a little bit of power and throttle response and maybe a differant sound. Im not tryin to race and Im not swapping engines (I wish i was though) My budget is a couple (ok ok maybe a few) hundred bucks. Im trying to find newer and better parts to put on my engine to attain these goals. Here is a super old thread I started when I first came to this site.
http://www.bonnevilleclub.com/forum/...819&highlight=
I just want to verify that this info is correct.
1. An L27 upper intake will fit on my engine and possibly flow better
2. The newer exhaust manifolds are slightly better than the LN3 ones, but if the LN3 ones have that restriction near the downpipe removed the differance is negligable.
3. The L27 throttle body is a bit better and will bolt on.
4. The heads with roller rockers from an L27 will fit as well.
Engines arent my thing so I am definately at noob status. Ive learned a lot just from what Ive taken off and seen first hand. (i didnt even really know what exactly an upper intake was
) Ive been going in circles lately trying to get my information straight so I need to figure this out once and for all.
Oh and Im gonna feel really dumb after this but where is the lower intake manifold and what does it do?? All I see is the upper part and the heads and block.
http://www.bonnevilleclub.com/forum/...819&highlight=
I just want to verify that this info is correct.
1. An L27 upper intake will fit on my engine and possibly flow better
2. The newer exhaust manifolds are slightly better than the LN3 ones, but if the LN3 ones have that restriction near the downpipe removed the differance is negligable.
3. The L27 throttle body is a bit better and will bolt on.
4. The heads with roller rockers from an L27 will fit as well.
Engines arent my thing so I am definately at noob status. Ive learned a lot just from what Ive taken off and seen first hand. (i didnt even really know what exactly an upper intake was
) Ive been going in circles lately trying to get my information straight so I need to figure this out once and for all. Oh and Im gonna feel really dumb after this but where is the lower intake manifold and what does it do?? All I see is the upper part and the heads and block.
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From: Jenison, MI (Near Grand Rapids)
I'm sure others more knowledgeable than I will soon jump in, but I'll start:
The L27 intake (complete - metal and plastic - not just upper) should bolt on, but the L27 has a different PCV system, with extra ports in the heads and intake for it. You'd have to figure something out for that, or swap heads and intake together. But if you were considering heads anyway, there ya go.
A quick search found this old thread that I read once upon a time:
Click it!
Some good information in there for you.
The L27 intake (complete - metal and plastic - not just upper) should bolt on, but the L27 has a different PCV system, with extra ports in the heads and intake for it. You'd have to figure something out for that, or swap heads and intake together. But if you were considering heads anyway, there ya go.
A quick search found this old thread that I read once upon a time:
Click it!
Some good information in there for you.
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From what I see, you will have to have the Total top end off the L27 and the heads, as well you'll want the L27 Exhaust manifolds too.. If you plan on doing this, you might just as well get all of the parts for the upgrade.. Keep all of the nuts and bolts you can from the donor motor as well... You'll need them in case you loose any... 
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If i swapped the head, intake and exhaust together I can use the new PCV style without changing anything correct? I dont want to have to make any parts, I want to use only original parts. I found a thread discussing the EGRless systems. This is a quote from jr's3800.
Does this mean that If i get all the parts from a 93 it should all work?
Another question. Will the TV cable from the transmission hook up to the newer throttlebody?
Funny how GM killed off the EGR on the L27 engines for 90,91 and 92 only to add it to the 93... the 89-93 3300 was also EGR'less ... Now the L27 and L67 are different in terms of NA and SC...
But, In 93 GM reinstalled the EGR on the L27, they didn't do this to the 3300 as 93 was the last year for it.... I have seen a series of L27'* and 3300'* that had burnt valves... Some did some didn't... And GM did not reinstall the EGR for emissions, it wasn't even needed.. But it sure did solve the issue of the Burnt valve syndrome...
But, In 93 GM reinstalled the EGR on the L27, they didn't do this to the 3300 as 93 was the last year for it.... I have seen a series of L27'* and 3300'* that had burnt valves... Some did some didn't... And GM did not reinstall the EGR for emissions, it wasn't even needed.. But it sure did solve the issue of the Burnt valve syndrome...
Another question. Will the TV cable from the transmission hook up to the newer throttlebody?
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Yes this should work....
On the TV Cable, you may have to Fab it up a bit to make it work, but I am not 100% on that... There were some years that had an L27 but still had the possibility of a THM440-T4, so you might find a bracket that may work..
You will really need to get the LN3 and L27 side by side to get a good look at what will and won't work..
I have thought about changing to the L27 Top end complete with heads... But Haven't had the time to dig really deep into it..
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On the TV Cable, you may have to Fab it up a bit to make it work, but I am not 100% on that... There were some years that had an L27 but still had the possibility of a THM440-T4, so you might find a bracket that may work..
You will really need to get the LN3 and L27 side by side to get a good look at what will and won't work..
I have thought about changing to the L27 Top end complete with heads... But Haven't had the time to dig really deep into it..
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Yes, if you swap heads and intake from an L27, you'll be all set with the PCV system.
Also yes, you will want to be sure you get a '93-95 L27 setup, with the EGR. EGR-less L27'* tend to burn valves.
I suspect that is why it was suggested that you get the exhaust manifolds too, since the EGR is on the back of a LN3, on the front of a L27, the port for it on the exhaust might be in a different spot.
The TV cable I am not sure about... If I'm thinking correctly, a L27 won't have a TV cable on it, because the newer electronic transmissions don't have a TV cable, right? Hmmm... Might need to visually compare the two throttle body linkages. Maybe the LN3 linkage/bracket will attach to the L27 TB? Just shooting out ideas...
Also yes, you will want to be sure you get a '93-95 L27 setup, with the EGR. EGR-less L27'* tend to burn valves.
I suspect that is why it was suggested that you get the exhaust manifolds too, since the EGR is on the back of a LN3, on the front of a L27, the port for it on the exhaust might be in a different spot.
The TV cable I am not sure about... If I'm thinking correctly, a L27 won't have a TV cable on it, because the newer electronic transmissions don't have a TV cable, right? Hmmm... Might need to visually compare the two throttle body linkages. Maybe the LN3 linkage/bracket will attach to the L27 TB? Just shooting out ideas...
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This is excellent news 
As far as the TV cable, im sure it can be adapted some way. Like I mentioned before, my dad is helping me with this, but what I didn tsay is that he is not really a fan of messing with something that worked fine to begin with. I need to fnd a 93 engine to compare. Could anyone with a 93 take a picture of theyre set up and I could compare it to what mine looks like?
As far as the TV cable, im sure it can be adapted some way. Like I mentioned before, my dad is helping me with this, but what I didn tsay is that he is not really a fan of messing with something that worked fine to begin with. I need to fnd a 93 engine to compare. Could anyone with a 93 take a picture of theyre set up and I could compare it to what mine looks like?
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I happen to have a '93 out in the driveway. If you let me know what kind of information/pictures you need, I'll be happy to supply them. It'* dark right now though...
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I would like a picture of your EGR set up, and one of the throttlebody where the cables attach. Also of the bracketry for the TB linkages.
This is a pic of my TB linkages. (not bad for a camera phone)
This is a pic of my TB linkages. (not bad for a camera phone)