Leith280zlt1 Posted July 12, 2005 Share Posted July 12, 2005 I was just wondering if someone give me some ideas for bolt ons on a LT1 TPI. The only thing I know of is the bigger throttle bodies and I'm planning on getting one soon. What I have right now is a pretty good setup. I'm right at 395hp but I'd like to get that last little bit to get me a little over 400. What I've done to it is all internal. I've ported the heads, intake, and corvette exhaust manifolds to match the gaskets. Bigger valves, I think they were 2" intake and I did a performance valve job on the heads. I zero decked the block and cut the heads down to get 10.5:1 compression ratio. I got a taller cam, it's pretty hot but I would have to look it up to see how much taller it is. It gets it a pretty good lope but not too radical. I balanced the crankshaft and rods. I also bought a custom performance chip for the computer. I tuned the fuel pump on the dyno and I think it was best at like 42 or something. Can't remember exactly. I'm just looking for some things that I can do to make it run it's best and get everything out of it I can. Thanks. Quote Link to comment Share on other sites More sharing options...
MYRON Posted July 12, 2005 Share Posted July 12, 2005 Might want to look into an hi-po fuel pump, injectors and pressure regulator.. Maybe some 36lb injectors. Also look at an upgraded coil or MSD box for it.. Maybe get you hands on the LT1 edit software and tune it yourself via laptop. Myron Quote Link to comment Share on other sites More sharing options...
dmyntti Posted July 12, 2005 Share Posted July 12, 2005 Other suggestions would be headers, cold air intake and an electric water pump. So should check the LT1 forums at fbody.com and cz28.com, all your questions could be answered there. I am considering getting a stage 1 heads and cam package from Elliot Portworks. High is highly regarded on both of those furums. His Stage 1 kit makes 380 at the wheels. http://www.eportworks.com/LT1LE1.htm Your Corvette exhaust manifolds are holding you back. Also look into bypassing the coolant in the throttlebody and 1 160 degree thermostat. Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 12, 2005 Share Posted July 12, 2005 How 'bout some custom made long tube tri-y 1.75" into 2.25" into 3" collector headers into a single 3" exhaust with a Dynomax muffler? I removed this system from my stock LT1 to improve my ground clearance. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted July 12, 2005 Share Posted July 12, 2005 Hay bartman do you mean that the headers are for sale? If so I'm first in line. Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 12, 2005 Share Posted July 12, 2005 Hay bartman do you mean that the headers are for sale? If so I'm first in line.They are for sale, though I haven't listed them yet. I would like to sell the complete exhaust system, but I'm open to offers. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 13, 2005 Share Posted July 13, 2005 An MSD Ignition system would probably get you over the 400HP mark. Up graded to the electric water pump is also a way you might pick up a couple HP. The electric water pump is just a good idea to get that shaft going from the water pump into the timing cover removed so you dont have coolant leaking into the timing cover. That's why I put in a electric water pump. I have one question though, what do you mean you cut the heads down to get 10.5:1 ompression? Stock compression should already be at 10.5:1. What kind of vehicle did this engine come out of? Guy Quote Link to comment Share on other sites More sharing options...
getZ Posted July 13, 2005 Share Posted July 13, 2005 Invest in a wideband O2 sensor and see how it is running. I'm always amazed to see the gains some people make with some dyno time and a bit of tuning. Of course that will probably mean getting a new chip made. Quote Link to comment Share on other sites More sharing options...
Leith280zlt1 Posted July 13, 2005 Author Share Posted July 13, 2005 I believe stock compression for a LT1 is 8.5:1. That is what mine was when I cc'd the heads and checked it. It came out of a '92 'vette. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 13, 2005 Share Posted July 13, 2005 No it should have been 10.5:1 and the LT4 is 10.8:1 because they have 54cc heads were as your heads would have been 58cc's. If it was 8.5:1 it would be a real pooch stock. That kind of compression is for a blower/turbo set up. You would have to have dished pistons get that kind of compression or really big cc heads. You cant tell compression just by cc'ing the heads. Guy Quote Link to comment Share on other sites More sharing options...
Leith280zlt1 Posted July 14, 2005 Author Share Posted July 14, 2005 I know how to check the compression ratio. I built the engine in my own shop. I don't know what heads I had or what year model they came off of. I didn't pull the motor out of the car, I bought it from one of my customers. I think it was from a '92 model car. I know I pulled some parts off a little older engine but the heads I cc'd were, if I remember correctly, 63cc aluminum heads. I have it blueprinted. I think the cast iron heads I have are 8.5 and the aluminum ones were 9.3 or something. I measured it regardless. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 14, 2005 Share Posted July 14, 2005 Im not saying your engine isnt at 10.5:1. But if you have 63cc heads then you would have to have a either no valve relieves or a slight dome on your pistons because a stock 92' vette had 10.5:1 with the 58cc heads. If your bottom end is stock then you dont have 10.5:1. The only heads that will fit on an LT1 are ones that are designed for an LT1. Older heads will not fit on it. The only heads that you can swap on to it would have to be off of another LT1 or an aftermarket heads specifically designed for the LT1. This is because it is a reverse cooled engine and has a differnet coolant passage design. Are you sure you dont have an L98? http://www.automotiverebuilder.com/ar/ar99928.htm Im not trying to start a argument here, I just like to keep the facts straight so that misinformation isnt spread on to the next guy that does a search for LT1 info. Guy Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted July 15, 2005 Share Posted July 15, 2005 http://www.tpis.com Quote Link to comment Share on other sites More sharing options...
fastzcars Posted July 15, 2005 Share Posted July 15, 2005 You know I have to agree with 80LT1 on this. The L98 and LT1 have enough of a difference to make them 2 different animals. The heads would bolt up but the water and intake ports are slightly different, and way leak. Quote Link to comment Share on other sites More sharing options...
nullbound Posted July 15, 2005 Share Posted July 15, 2005 They are for sale, though I haven't listed them yet. I would like to sell the complete exhaust system, but I'm open to offers. please consider me to be next in line. i'll take the whole kit. Quote Link to comment Share on other sites More sharing options...
Zoldman Posted July 15, 2005 Share Posted July 15, 2005 The only car the LT1 engine was available in for 1992 was the Corvette. If you engine did not come from a Corvette, it isn't an LT1; and is most likely an L98 TPI engine. From the compression ratio you mentioned, I would think it is an L98. The LT1's were either 10.5/1 or 10.8/1. The easiest way to check is to find the distributor. If you can't find it where a regular small block Chevy has one, it could be an LT1, since the LT1 used the Optispark distributor that is mounted behind the water pump. If you can post a pic of your motor, I'm sure someone can identify it for you. Bill Quote Link to comment Share on other sites More sharing options...
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