Help choosing a motor
 

Well I am in the market for a Shortblock. Was going to have one built but it will be a little to pricey for me @ 3600.00 for a stock LS1 with forged rods and pistons. I decided to see about buying a already built shortblock and have the machine shop work my heads a little and assemble the complete motor. I have narrowed it down to 2 shortblocks and just want to get everyones impressions on them..

1st will be a 347 motor. It has Diamond pistons, Eagle Rods and a stock Crank. With my 243 heads Compression ratio will be around 9.5:1. Perfect setup for a blower in the future. The motor was assembled by a Machine shop in FL and is a balanced rotating assembly. Comes with Double roller Timing chain, Oil pump, ARP 2000 rod bolts, Arp Main studs. front and rear covers as well. I have a ton of pics on this motor. This one is 2650 shipped coming from Mississippi. I like the motor but dont know personally the shop that built it.

2nd is a 383 LS1. Diamond pistons, Eagle rods, and Eagle crank. The motor was built by a very good shop in Virginia Beach that I have dealt with in the past. The motor made 480rwhp on motor. The Short block comes with the Cam, and pretty much everything except the intake, Heads, and oil pan. The compression ratio with my heads will be around 11.0:1. The only downside is that the motor has 7k miles on it and has been dynoed and beat on a little. That could be a good thing as everything should be broke in. The oil pressure is 35psi at hot idle and rises up to 70psi depending on throttle. The seller is building a big cubed motor for a supercharger. He said he will send a video of the motor running before he pulls it and will send a ton of pics. Not sure if it has ARP main studs or stock GM main cap bolts. The price on this motor is 2650.00 shipped. It is coming from NY state.

I am leaning towards the 383 because it makes really good power and is a really good price. The only thing is that it is used. That might be a bad thing or could mean that it has been broke in and ready to run! I know the shop that put that motor together and know they do great work on LS1s. The other motor is brand new which would be cool because I can break that motor in from 0 miles but I have no Idea about the shop that built that one except for members from LS1tech that have posted about how good that machine shop is.

So you have a new (supposedly) stockish motor built by a mystery shop, or a slightly used, built motor made by someone you trust completely for the same price.....

Does Motor 1 come with a cam, etc? (it doesn't appear to from what you're saying). You mention motor 2 just needs intake/heads/oil pan.

Definitely sounds so far like the 383 is the way to go.

I like the 383 myself. No replacement for displacement and you know the shop. Can you get a few bucks knocked off if you pick it up yourself instead of shipping it? Or would that not be worth the gas money?

Call me crazy, but if you go with the 383 I'd pull the valve covers and oil pan and have a look before I give him the cash (of course, I'd pay for gaskets if I said no). You just never know.

comes without oil pan, intake, and heads so he should be able to see everything without worrying about gaskets.

well first off you are talking about a low compression shortblock and a higher compression long block. two very different things. if you have a goal, say a turbo in the future, don't spend the cash twice. second that 383 power is coming through a different set of heads which you made no mention of work done to them or being done to yours. are you planning on spraying the motor or putting a large cam in it or what? gotta know your gameplan before telling you option a when really b is what you wanted. 8-)

RIF.

Thanks.

Its not really a mystery shop. I looked them up on Tech and they have done some good work on LSX motors. I personally never heard of them or know anything about them. I do know the other shop and know 1st hand they do quality work.

The 347 comes with no cam

I could but he lives in Rochester NY. Its a good drive from the Philly area..

I am talking about 2 shortblocks, 1 built for all motor or N20 and the other built for Boost. They both come with everything but the Heads, Intake, and oil pans. The Boost motor does not come with a cam but the 383 comes with a cam.. I would love to do a turbo motor but the more I think about it I really dont want to spend more money on parts then my car is worth. I did that once already with my 98 V6..

I said I have a set of 243 heads that the machine shop will do some work on. The 383 had some patriot performance 5.3 heads. His compression ratio is at 11.5:1. With my 243 it should be a little lower then that.. The cam that comes with the motor is a 238/248 duration comp cam. Its a good size cam. Like I said in his Vette the car made 480rwhp. I am shooting for 440rwhp all motor. If I want I can thow a 100 shot on it or more and make who knows how much power.

Thanks everyone for your suggestions. I really was just wonderring what you would do if you were in my position.

now with that response i would definitely consider looking at the 383. i am not familiar with gen 3 heads so i don't know if you are gaining or losing with the 243's. even still you just want to match the cam to the head flow and factor in the added displacement. seems like it would make a great strip car with some fun on the weekend.

243 casting number heads are Z06/LS2 heads. The ones I have are off a 04 Z06. They have the light weight sodium filled valves. The 243's on the LS2's have stock valves. Dont know how much of a difference they make. The 5.3 heads are truck heads. Dont know what will flow better worked 243's or worked 5.3's?

Why not just have one built to your specs? It would take any guessing and what-ifs out of the equation.

I would save my money and wait until you have enough to get what you really want. Look at everything and plan carefully.

There were 3 specs I was considerring, Supercharged/Turbo motor, N20 Motor, All motor Motor.. Thats why I narrowed it down to these 2 motors since they cover all 3 specs..


Was thinking the same thing untill I got qouted the price for building a shortblock! I built my V6 motor to the specs I wanted it to be at and did everything up the way I wanted it and it cost over 5000.00 to build that longblock. I would be looking at 3600 to just build up the short block with forged rods and pistons on a stock crank. Thats not including headwork or full assembly. I could buy a forged shortblock from a company like SLP or Texas speed but they run in the mid 4000.00 range not including oil pumps and timing chains and what not.

I would be happy with probably just heads and cam on my car and make 420rwhp but my motor has 94,000 miles on it. I would want to freshen up the bottom end of the motor since I would have it torn down pretty far anyways and what not. If I were to do that then why not just put a bigger and stronger motor in there for about the same price if not less?

Price cut, means corners cut. IMO of course.

On motor choice, since you are already a nitrous junkie, why not stick with what ya know?

That is of course, unless you are tired of filling the bottle.

why not look at tsp? they have some amazing short and long blocks and their prices arent too outragous. this is what im leaning towards for my lq9 build next year:

http://texas-speed.com/shop/item.asp?itemid=46&catid=28

Nitrous junkie? I havent had spray on my car or sprayed a car in over 5years.. I guess I have been in recovery for the past 5 years..

If a motor was built by a good LS1 Machine shop and they used pretty much everything that every other LS1 engine builder uses how is that cutting corners? These motors are not ebay rotating assemblies or being shipped from China or what not.

I bought my WS6 used so I guess I was cutting corners on that purchase as well right?

What I know is that you dump a **** ton of money into a motor or you save some money and by an already built motor. In the end you are happy because you have a 4000.00 motor with the best parts out there with 0 miles on it or you have a 2500.00 motor with the same best parts out there that has 7,000 miles on it..

Thats were I did start looking at builds. Very nice but by the time those motors are ready for install you will be looking at close to 7000.00. Thats a little out of my price range.

QFT.

Thats why I'm having a motor built to MY spec... Not someone else's.


"Beat on a little" Now, thats just redundant, eh?

7,000 is alot on a motor... thats ALOT of 1/4 passes... and any nitrous passes already? Ever been refreshed?

Thats great for you. I did that with my old car. My T/A hasnt been on a race track since 2006. When or if I get this motor it wont see a track for a long time if at all. I am not trying to set any records or achieve any ET's I am just looking for a fun car that has a bad ass motor in it that in the future if I get bored with it , I can put a shot of N20 on it and turn it into a new car without having to worry about blowing it up. I will take it down a track again but not untill I get at least a Rear end. I am not a track guy anymore. Hell I moved back to NJ 2 years ago and was so happy that Atco was 8 miles from my house that I have raced there 1 time since I have been back.


Said its never had N20 on the motor. The guy was in the Navy stationed in Vabeach and got out earlier this year. He is from Rochester NY which is probably 500 miles or so from Vabeach. He had the motor installed in 2008 and said he took it easy for 1000 miles. He also said he drove the car back to NY 3-4 times since installed so that would account for a couple thousand of the 7,000 miles. I did not ask him how many passes he made if any at the track. The guy sells a bunch of parts on tech and his 150 + positive feedback is evident on how he does business with others.

Its like buying anything used that an important piece to your car. Trust between the buyer and seller. Was looking at a used 12bolt on LS1tech a while back. Guy said it has very little miles on it like 1100 or so and never raced but in seeing pictures of his car on his fquik page with with the 12 bolt installed and sitting on skinnny fats with MT ET streets on it makes you think. Turned out He ran it alot.

Thanks for the reply and you do have a very valid point. Thats why I am still up in the air about this. I can just do my heads and cam on my motor with 94,000 miles on it but I dont know if that would be a good idea or not. Then I could start to build the motor I want to build. The problem is I am married with a child and my car budget is not what it use to be.

Jeff,

I would honestly suggest doing a compression test on your motor to see where that is... my 98 motor with 118k still looked brand new when I had it apart...

Thats a really good idea. Thanks for the suggestion. Did not even think about that..