Michael Savage Posted April 7, 2014 Report Share Posted April 7, 2014 I got to looking at some motors today. Could you put 3500 heads-non VVT matched to 3900 gaskets on a 3900 Block. Then match 3100/3400 lower manifold to the 3500 heads/gaskets. Bolt it all together and have a 3100 sleeper engine using the 3100/3400 sensors. Virtually having a Non-VVT 3900 running as a 3100/3400? Using the 3100/3400/3500 headers. Anyone ever attempted this? The parts should all interchange with some gasket matching with a dremel. I figured if you could do that, you could have the best parts of all those engines with a stock seeming setup. I don't want to hear about a complete swap, I want to know if there's any way you could do this Hybrid type setup with all these engines, since there setups are generally the same. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 7, 2014 Author Report Share Posted April 7, 2014 I figure this should be possible, people have put 3900 heads on 3500 blocks, so why not the reverse? Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted April 7, 2014 Report Share Posted April 7, 2014 youd be a trailblazer so id say take your budget that yer figuring and triple it id bet you could do it, even to the point of using a manual rpm triggered vvt control scheme if ya wanted... Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 7, 2014 Author Report Share Posted April 7, 2014 Hmm Manual RPM VVT Control, any links to info on that? Also budget wouldn't change, can put the 3500 top on a 3900 block at pull a part and buy it as a whole for $185 the 3500 and 3900 head gaskets have the same exact part numbers. So I'm guessing they're the same. I figure if I could get that setup it could be a bad 3100 sleeper. I set it up with those combined specs on Desktop Dyno and looking at about 348 Torque at 4500rpm. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Night Fury Posted April 7, 2014 Report Share Posted April 7, 2014 That's not possible. You can't get more power by using shittier parts Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 7, 2014 Author Report Share Posted April 7, 2014 Bigger valves in the 3500 heads and ported and polished. Mostly all the parts are the same intake wise just different shapes. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 7, 2014 Report Share Posted April 7, 2014 i don't remember why, but i seem to remember that the gen 3.5/3 heads not working on the gen 4 block(or gen 4 heads on the 3/3.5 block). Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 7, 2014 Author Report Share Posted April 7, 2014 3500 Non-VVT Heads should bolt up to a 3900 block, they use the same head gaskets strangely enough Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Night Fury Posted April 7, 2014 Report Share Posted April 7, 2014 Bigger valves in the 3500 heads and ported and polished. Mostly all the parts are the same intake wise just different shapes. Sent from my iPhone using Tapatalk Which still leaves you with equal than or smaller ports than stock 3900 parts, how does that translate to more power? Plus this whole idea reeks of a lean running or air starved engine. Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted April 7, 2014 Report Share Posted April 7, 2014 We should totally get some beer and time at a pull a part and find out the answers to all these questions. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 7, 2014 Report Share Posted April 7, 2014 3500 Non-VVT Heads should bolt up to a 3900 block, they use the same head gaskets strangely enough Sent from my iPhone using Tapatalk the VVT 3500 and VVT 3900 use the same headgasket(Felpro 26324PT, Victor Reinz 54649 for left side, Felpro 26325PT, Victor Reinz 54648 for right side). the non-VVT 3500 is a different gasket(Felpro 26314PT, Victor Reinz 54647). there is also the issue of cylinder offset on the VVT engines. you can bolt the heads on, but the chambers are in the wrong spot and the gasket will overlap in some places and underlap in others. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 7, 2014 Author Report Share Posted April 7, 2014 What if you modify the gaskets and the cylinders in the heads? Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Night Fury Posted April 7, 2014 Report Share Posted April 7, 2014 What exactly would be the point? You asked, and the basic simple answer is no. Just get a non vvt 3500 or 3400 and throw it in there Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 7, 2014 Author Report Share Posted April 7, 2014 Yes I could but I would like the 3.9inch bore from the factory. But I guess a 3500 and bore it our would work easier, but cost as much and the engine itself lol Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
skitchin Posted April 8, 2014 Report Share Posted April 8, 2014 I'm not as familiar with these parts so was wondering what the benefit of using each part would be? I'd guess something like 3900 block because big bore, 3500 heads because non-vvt/different comb chambers=different compression, and mebbe 3400 manifolds = better flow?? Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 8, 2014 Author Report Share Posted April 8, 2014 3400 manifolds have justifiably the same flow as the 3500. But it's going in a 3100 so the upper would be 3100/3400 to keep all the sensors and hoses the same so it'll be an easier plug and play. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
skitchin Posted April 8, 2014 Report Share Posted April 8, 2014 Any idea how big the difference is in the size of the combustion chambers on the 3500 heads vs the 3900? Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 8, 2014 Author Report Share Posted April 8, 2014 Apparently it won't work because they're too offset. Get a 3500 non-VVT bore it out to 3.9 put 3900 piston heads on it and then add bigger valves. Seems to be the way people are saying to get it to work. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
skitchin Posted April 8, 2014 Report Share Posted April 8, 2014 Hmm what sort of bore tolerance do the 3500 blocks have anyways? Enough to manage that? And if it's at all like what GM does on the LS engines, main differences for VVT will be the timing cover, cam position sensor, cam gear, and the cam itself. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 8, 2014 Author Report Share Posted April 8, 2014 That I'm unsure of but there bore is 3.7 so 3.9 won't be too bad. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 8, 2014 Report Share Posted April 8, 2014 What if you modify the gaskets and the cylinders in the heads? Sent from my iPhone using Tapatalk modifying a MLS gasket(gen4) or a graphite gasket(gen3.5) is a horrible idea, as is trying to reposition the chamber..... it just isn't doable without completely screwing everything else up. Apparently it won't work because they're too offset. Get a 3500 non-VVT bore it out to 3.9 put 3900 piston heads on it and then add bigger valves. Seems to be the way people are saying to get it to work. Sent from my iPhone using Tapatalk IIRC, Ben tested larger valves on the 3500 heads and got little to no improvement. That I'm unsure of but there bore is 3.7 so 3.9 won't be too bad. Sent from my iPhone using Tapatalk no way are you overboring it .200", not in any economical way if it is even possible, you'll likely run into the water jackets in the block. .060" is already a significant overbore and on the edge of needing sonically checked for remaining wall thickness. you would still end up with the issue of the non-offset bore with the offset heads too unless you offset bore the cylinders, in which case you're REALLY spending time/money to get nowhere fast. Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 8, 2014 Author Report Share Posted April 8, 2014 I'll look into building the 3500 and forget boring it. As far as valves go ill mess with the different valve applications. Bigger isn't always better, switching the exhaust and intake valves sizes could do something, not definite, but possible. Adjusting the sizes virtually does show a difference. I'll look into the specific sizes making the best performance and let you know. I'll probably end up with a 3500 with a 3400 top swap in the end, but that could change. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted April 8, 2014 Report Share Posted April 8, 2014 Desktop dyno is like using an abacuss to figure out quantum physics. Take all "info" with lots of grains of salt.... Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 8, 2014 Author Report Share Posted April 8, 2014 Seems it's always been accurate with v8s if you read the users guide lol Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted April 9, 2014 Report Share Posted April 9, 2014 iirc that programs most accurate with the sbc/etc....70's n 80's tech....trying to use a program tailored around a different motor with all the factors different to guestimate yer power gains is gonna be a big disappointment. the program your looking for to guestimate things for a v6 is far more expensive and requires hundreds of data points that youll have to collect from component testing...before you can even plug in changes... Quote Link to comment Share on other sites More sharing options...
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