Z-28
Stock
Posts: 12
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Post by Z-28 on Aug 30, 2005 19:26:08 GMT -5
i dont know much about impalas, is the lt1 in an impala the same as a camaro?
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Post by metalbeast on Aug 30, 2005 19:33:11 GMT -5
No. The Z-28 LT1 has aluminum heads with smaller combustion chambers (58 CC). The Impalas came with cast iron heads that larger combustion chambers (64 CC). The cam is also different. The specs from year to year for all vehicles with LTX engines are shown below:
1992 Y-body: 205/207 0.451/0.450 lift 117 LSA
1993-1995 Y-body, F-body: 202/207 0.450/0.460 lift 116 LSA
1994-1996 B-bodies (including L99 4.3L): 191/196 0.418/0.430 lift 111 LSA
1996 Y-body, 1996-1997 F-body: 200/207 0.447/0.459 lift 117 LSA
1996 Y-body, F-body LT4: 203/210 0.476/0.479 lift 115 LSA
The low duration and tight LSA gave the B-body LT1 more low end grunt which was helpful in moving those heavy beast.
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Post by slow260z on Aug 30, 2005 20:09:19 GMT -5
Here is a site for different aspects of LT1's. I measured my aluminum and iron heads. 93 AL were 52 cc 95 Cadilac were 60 cc. I have heard many different sizes for chambers for LT1. I know the aluminum changed in later years, I have no data other than the one set for iron. LT1 and differences |
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Post by metalbeast on Aug 31, 2005 6:42:03 GMT -5
The heads on the Impalas should have 64 CC combustion chambers.
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Post by jdawgs94z on Aug 31, 2005 10:41:27 GMT -5
wasnt the impala lt1 more like a 265ci engine,i know the displacement was smaller but the hp difference was only 20 to 30 hp
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Post by metalbeast on Aug 31, 2005 11:42:20 GMT -5
wasnt the impala lt1 more like a 265ci engine,i know the displacement was smaller but the hp difference was only 20 to 30 hp No, the Impalas had 350 CI LT1s. Some Caprices and Buick Roadmasters got L99s, or "baby LT1s" as they are affectionately known as that were 265 CI (4.3L) versions of the iron headed LT1s. The horsepower difference was due to lower compression and different cam than other LT1s (the Impalas LT1s did produce more torque than their aluminum headed bretheren). |
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Post by jdawgs94z on Aug 31, 2005 14:16:21 GMT -5
yeah the iron heads flowed better,
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Post by metalbeast on Aug 31, 2005 20:22:20 GMT -5
yeah the iron heads flowed better, Yes they do. On average they flow 20% more than an aluminum head. However, the drawback to an iron head is that it is more susceptible to detonation than an aluminum head. This is because aluminum has a higher specific heat than iron and more readily disipates heat. The iron heads are also slightly heavier. |
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Z-28
Stock
Posts: 12
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Post by Z-28 on Sept 1, 2005 19:16:47 GMT -5
thanks guys
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Post by lawrence on Sept 7, 2005 7:44:39 GMT -5
I've got a '94 Impala LT1 engine in my '68 Camaro with the stock iron heads. I've also got a spare set of ally heads from a '94 Camaro. Is it worth swapping the ally ones on to gain a bit more compression, or leave the iron ones on for better flow?
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Post by metalbeast on Sept 7, 2005 11:01:30 GMT -5
I've got a '94 Impala LT1 engine in my '68 Camaro with the stock iron heads. I've also got a spare set of ally heads from a '94 Camaro. Is it worth swapping the ally ones on to gain a bit more compression, or leave the iron ones on for better flow? Its just my opinion, but I would swap the iron heads for aluminum ones and get a better cam. You'll be able to not only bump up the compression, but you'll save a little bit of weight as well. Are you planning on keeping the engine pretty stock or do you plan on modding it for more power? |
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Post by Fire67 on Sept 7, 2005 14:29:16 GMT -5
If you gasket match and blend the intake and exhaust ports toward the valve bowls you shouldnt have a problem making up for the loss in flow.
If your gonna have the heads completely machined, port the entire exhaust and intake ports. Or even pay someone to port them for you...
Then do like MetalBeast suggested and get a nice cam/rocker package to compliment your setup.
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Post by lawrence on Sept 7, 2005 15:24:20 GMT -5
It's my daily driver, so it's probably going to stay pretty stock. I may swap them over and put 1.6 rockers in at some point. Gas isn't cheap over here either (I'm in the UK), it's doing about $30 a day going to work and back. (about 20mpg). I'm also building a procharged LT1 for my '55 Bel air, so I guess I can jump in that if I want to go fast ;D
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Post by metalbeast on Sept 7, 2005 19:48:27 GMT -5
It's my daily driver, so it's probably going to stay pretty stock. I may swap them over and put 1.6 rockers in at some point. Gas isn't cheap over here either (I'm in the UK), it's doing about $30 a day going to work and back. (about 20mpg). I'm also building a procharged LT1 for my '55 Bel air, so I guess I can jump in that if I want to go fast ;D I would still recomend getting at least a mild cam. The Impala cams are pretty small and geared more toward developing low end torque rather than top end power. |
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Post by lawrence on Sept 8, 2005 6:53:14 GMT -5
d@mn it, I knew I should have kept quiet. Maybe the CC306 will be better in there than the '55..... ;D
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Post by metalbeast on Sept 8, 2005 8:45:57 GMT -5
Just make sure if you go with a cam that big or comparable to it, you need to upgrade your valvetrain components (springs, rocker arms, lifters, pushrods).
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