89oldscutlass Posted January 31, 2004 Report Posted January 31, 2004 I was just curious if anybody had built one. It doesnt take much to bore them up to a 3.4 sohc. I was thinking about putting one together. Cash is tight so I would have to buy a couple of parts at a time. My brother and me have been looking at the specs on a stock 3400 and the bore difference isnt much. I think its like 12 over a 3.1 and we are talking about going 30 over on mine. I will also be changing valves to help bump the compession up to 10 to 1. Any ideas guys? Oh and before someone suggest the 3.4 dohc I thought about it and I want a sleeper so when I pop my hood they see 2.8 on the intake. Just for shits and giggles you know. Quote
Robby1870 Posted February 1, 2004 Report Posted February 1, 2004 you cant safely bore a 3.1L block to 3.4L its too much. A 3.1L block can only handle like 60 or 80 over and 40 is 1mm over so that would be 90mm bore and I think the 3.4 is 92mm. Quote
89oldscutlass Posted February 1, 2004 Author Report Posted February 1, 2004 Ok guys the 3400 uses the same crank as a 3.1 or 3100 I knew that. Heres some of the the specs on them. 3400=(bore x stroke)=3.62 x 3.31 3.1 or 3100=(bore x stroke)=3.50 x 3.31 2.8=(bore x stroke)=3.50 x 2.99 See a 3400s bore difference isnt that much Robby its what about .12 over a 3.1 or 3100. Now the problem is thats only going to get me up to about 150 hp or so. Im wanting to bump up the compession from the stock 8.8:1 to 10:1 by putting bigger valves in th heads. Now the machine shop we use at the garage says if we go to high on compression were going to run a chance on blowing headgaskets. I found the cam Im wanting its not roller or a solid lift cam but its about a .467 lift versus the stock .273 lift. Im wanting to get up to about 250 hp at the crank I dont how n/a yet but im working on it. Quote
4spdz34 Posted February 1, 2004 Report Posted February 1, 2004 there are people with 3.1s and 3100s running 12:1 , why not go that high Quote
89oldscutlass Posted February 1, 2004 Author Report Posted February 1, 2004 Well I was going on what the guy said at the machine shop about blowing head gaskets as well as being able to run pump gas in it with out getting into spark knock problems. Quote
Robby1870 Posted February 1, 2004 Report Posted February 1, 2004 \ said: Ok guys the 3400 uses the same crank as a 3.1 or 3100 I knew that. Heres some of the the specs on them.3400=(bore x stroke)=3.62 x 3.31 3.1 or 3100=(bore x stroke)=3.50 x 3.31 2.8=(bore x stroke)=3.50 x 2.99 See a 3400s bore difference isnt that much Robby its what about .12 over a 3.1 or 3100. Now the problem is thats only going to get me up to about 150 hp or so. Im wanting to bump up the compession from the stock 8.8:1 to 10:1 by putting bigger valves in th heads. Now the machine shop we use at the garage says if we go to high on compression were going to run a chance on blowing headgaskets. I found the cam Im wanting its not roller or a solid lift cam but its about a .467 lift versus the stock .273 lift. Im wanting to get up to about 250 hp at the crank I dont how n/a yet but im working on it. Yeah, 120 thousandths is A LOT. Try and bore a 3.1L block over that much and I bet the cylinder walls wont last long. GM says a safe max over bore is b/n 60 and 80 thousandths for a 3.1L block. You're talking about 3mm over bore on each cylinder. Do it if you want. Im just telling what GM said Quote
Vegeta Posted February 1, 2004 Report Posted February 1, 2004 You can do .120 over but .060 is safe and anything over is pushing your luck. 12:1 works with pump gas, just make sure you put a wilder cam in it like the 260 or 272 grind. Just start with a 3400, its cheaper, faster, and easier. Quote
hazmatic Posted February 1, 2004 Report Posted February 1, 2004 when i built my performance 3.1 tubro i only bored it to a 3.2l cuz i knew it was safe to there is chart somewhere online that tells what it is to safley bore over wuts riskie n wut not to do Quote
JS91Z34 Posted February 2, 2004 Report Posted February 2, 2004 my Buddy did a 2.8 .060 over with edelbrock intake and cam and sprayed it with 100 shot of nitrous and never had problems. Quote
MaroonRegal Posted February 2, 2004 Report Posted February 2, 2004 10:1 compression + a Turbocharger = either a) very low boost pressure a very efficient intercooler c) Like 105 (or higher) octane fuel. d) 2 or more of the above Quote
Intlcutlass Posted February 3, 2004 Report Posted February 3, 2004 Quote I was just curious if anybody had built one http://www.turboz24.com/ I don't think anyone has done more than Curt. Quote
89oldscutlass Posted February 5, 2004 Author Report Posted February 5, 2004 Thats a mean little z24. Quote
89oldscutlass Posted February 6, 2004 Author Report Posted February 6, 2004 I checked at the garage today and we have a 3.4 camaro air pleniom. I wonder how hard it would be to do like that guy did making it work on our engines. Quote
Intlcutlass Posted February 6, 2004 Report Posted February 6, 2004 It's easy..... BUT.... You will need the upper AND lower plenum...I don't think there would be any isses with the heads...I could be wrong on that. I have heard that (for the Fiero guys), if you went to change the iron heads to aluminum, you also have to do the plenum... just something to think about...... Quote
Vegeta Posted February 6, 2004 Report Posted February 6, 2004 The iron head manifolds wont work with the aluminum heads at all. The ports are not even close. Quote
Intlcutlass Posted February 6, 2004 Report Posted February 6, 2004 \ said: The iron head manifolds wont work with the aluminum heads at all. The ports are not even close. Good job...I wasn't sure about that..... Quote
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