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Posted by: Dr. Roger Aug 19 2006, 02:03 PM

5.7 l engine, complete fuel injection setup, all accessories.

My '74 914 is running the 355cid carb'd SBC with oil control issues.

My pre '86 355 carb'd engine will get the oil control issue taken care of but in the mean time I'm thinking about just getting this low mileage running engine.


I know that the '96 year was the year when Chevy switched over from the LT1 to the LT4.
Iron to aluminum heads.
higher compression
bigger valves
higher redline


Whatcha think?

Posted by: 73Phoenix20 Aug 20 2006, 07:48 AM

Actually, Chevy didn't "switch"... they started offering the LT4 330 hp with manual trans only for the 96's as an option, and morphed that engine into the 1997 LT4 345 hp engine... so most 96's are LT1's, not LT4's...

That said, the LT4 seems to be an okay motor... I had a 2000 example, and it ran great albeit seemed a bit under powered... felt more like 300 hp then 345 hp, but I never dynoed it so can't say...

Posted by: tesserra Aug 20 2006, 08:20 AM

What kind of oil control issues?

I played your clip of the car running, sounded great.
What starter did you use? That motor cranks over fast.

Posted by: bondo Aug 20 2006, 09:05 AM

The Corvette and the Camaro/Firebird LT1s were all aluminum headed. Only the Caprice/Impala have Cast iron heads. It is VERY unlikely that it is an LT4.

The Corvette LT1 is nearly identical to the Camaro/Firebird. The only differences I know of are the cam, and 4 bolt mains. The accessories are different too.

An LT1 in a 914 is a total custom job for everything but the adapter plate. Engine mounts are different, flywheel has the late balance, the water pump setup is completely different, and I think the pulley sticks out the front a little more to accomodate the optispark, so your belt system will have to be custom. The intake manifold will have to be turned around. To do it right requires a little welding.

1996 is the first year of the OBDII LT1. Not a huge deal, but it adds to the complexity a little. Any LT1 newer than 1994 also has a mass air flow sensor, so that's one more thing to mount. The nice thing about the later ones is they're easier to convert to LT4s. The LT1 is a very nice engine. You'd be hard pressed to get the unique combination of performance and really nice street manners out of a "normal" SBC. It's not easy, but I think it's worth it (which is why I'm doing it).

Posted by: bondo Aug 20 2006, 09:09 AM

That there is an LS1, not an LT4. Note the plastic intake manifold. The LT4 has a red painted aluminum intake manifold. The LT1 has just a bare aluminum intake manifold.

Posted by: bondo Aug 20 2006, 09:37 AM

Here's the best sites I know of:

http://www.hpsalvage.com/lt1.htm

http://www.grandsportregistry.com/lt1vslt4.htm

http://en.wikipedia.org/wiki/GM_LT_engine

http://www.theherd.com/articles/lt1_cool.html

http://www.automotiverebuilder.com/ar/ar99928.htm

Read up!

Posted by: Dr. Roger Aug 20 2006, 01:42 PM

tesserra,

thanks, the engine was using a chevy truck starter with an adaptor plate. I decided to switch to an Ebay mini-starter which doesn't use an adaptor plate and turns over the SBC just fine and is a huge weight reduction.

as for the running during the video, she ran great but since then she's been overheated a couple of times and who know's what's going on inside the engine now. i'd rather troubleshoot sooner than later and get a new head gasket installed first thing.

the plugs foul very slowly (it's taken a few months of low-mileage driving to get 'em fouled) but if a valve stem isn't getting oil I've got some real issues to address. ($$$)
Summit has the Edelbrock Performers with 2.02" intakes and 63cc chambers for abour $500 a piece assembled.

royce,
thanks for the resources!
geez, my problem is i find these great deals on complete, low mileage, engines and then i look in my checking account. no wonder i'm broke.

that LT1 is such a nice engine. if i could get 300+ ft.lbs. from 1800-6000RPM's 'd be set.

after reading about all the mods i'd have to make, it's looking like I should fix what I have and give her a little head upgrade which'll save me a few bucks in the long run.

after this career change is complete, i'm going to definately make a power plant upgrade. i hate being limited by money.