Machine shop
 

What's a good machine shop to send a set of heads to to get planed, ported and polished, bored and whatnot? I want to get these damn 3.1 3100 heads out of my garage. I figure if I get them modded for the 3400 I can put them to good use. And no, I don't want to go by a set of off the shelf heads if I can avoid it.

send em to wot-tech.....

I got an email from Ben at Wot-tech this morning. He said that the 3100 heads and the 3400 heads from the year 2000 are exactly the same, and I wouldn't have to do anything to make them fit. I thought there was a difference in bore, so I asked him if it was only in the block, and not the head. If this is true, it's very good news for me. I can use the 3100 heads that I have to make my drawings for the exhaust manifolds I want to make. I could even get those heads sent to over to WOT-tech and get them done up. I really hope this Ben character is right...

Double check then.

Do a parts search on www.car-parts.com

Well, I just searched for a 2000 Alero with the 3.4 (California Emissions) and both 3.4 and 3.1 heads came up in the list. Sweet. :yahoo:

any reason why your swapping the heads? you going to do more engine work or what

I have header flanges available if you want to make a set of tubular manifolds. If someone is in florida, I have a guy that will make a set of headers for a good price so we can offer them to everyone. Just throwing it out there since I don't know what you are up to with the exhaust.

The older 3100 heads have a 1.72" intake valve and are a worse casting quality than the 00+ and 3400 heads used. Head castings ending in 170 and 487 are the ideal heads. 487 being newer and either 10mm rocker studs or 8mm. 8mm was changed in late 02, officially 03. All 3500 heads are 8mm.

Any more questions, let me know. I like forums because then everyone can see the discussion and get the answers:)

I completely forgot about the intake and exhaust valve diameter differences. I guess that should be a given being that they are two completely differently sized engines. I'm not planning on swapping the heads, yet. I've tried selling them and have had no takers. If I can get them modded to fit the 3400, with larger valves and port/polish I might sometime in the future. I'll get the casting numbers tonight, I keep forgetting to do that. My main goal is explained in this thread:

http://www.aleromod.com/forums/showthread.php?t=25988

The exhaust valve size hasn't changed in a long time but the intake valve changed for the 3400 in 96 and the 3100 in 2000. They really aren't completely different sized engines. .3 liters is nearly insignificant other than you deshroud the valves more with a larger bore, but you have further for the flame to travel during combustion.

Yeah, more detail than you asked for:P I don't know what you are doing with blueprints though. Just to have? I have some block specs but not cylinder heads. What you want is similar to my 95 3400 DOHC (as its called) book with all the engineering specs. GM internal document that found its way on ebay:P Good like finding what you need.

The only reason I asked for blueprints is because I know that would give me above and beyone what I really need. I just need to measure out the exhaust ports and bolt pattern so I can start on some custom headers. Since that part of the 3100 heads should be the same I'm good to go. I wanted to avoid having to tear down my engine just to take some measurements. I will definately post once I get them made up. I've got AutoCAD 2009 LT, but I'll be sure to make some PDF files for easy sharing.