vortec 454 to 8.1 swap

[dietzster]

Has anyone sucessfully done a 454 to 8.1l swap. I have a 98 vortec 454 and am doing research on putting in a 8.1l (L18) motor. I want to use the block and rotating assy of an 8.1 then put on 454 heads and factory intake and fuel injection to keep the swap simple. And put in a different cam to get the 454 firing order. I think it will work since the 454 and 8.1 block and bottom end are pretty much the same (8.1 same bore but .370" more stroke). The only concern I can see is the factory 454 intake going on the 8.1 tall deck block, is it as easy as putting spacers between the heads and intake? Also distributor length, are they different from short and tall deck engines? Also are the push rods longer on a tall deck block? The rest should be a piece of cake. Hopefully someone that really knows tall deck engines will chime in. What do you guys think? Or does anyone have a good link to a site that has mechanical differences in short and tall deck blocks. ANY help or comments appreciated. Also does anybody know with 100% certainty if the 454 heads will bolt on an 8.1? I have studied pictures religiously and I think they will but don't have an 8.1 block to test it out. I know there are 2 extra holes in the 8.1 block but they will be covered by the head and gasket and shouldn't cause a problem.
Thanks

[Big Dave]

Only parts that interchange is the oil filter. Can not be done. Different motor entirley.

Big Dave

[COLD]

Just put a stroker rotating assy. in your 454 and you will have 489@.030 overbore or 496@.060 overbore. Eagle or Scat have kits. Like Dave said. Completley diferent engines.

[dietzster]

I'm telling you it CAN be done! It's just no body has done it yet. Those engines are way more similar than you think, just cause they look different from the outside, doesn't mean anything. I don't want a stroker kit cause I can get a complete 8.1 for cheaper than a stroker kit and cost of machining. I just found a sit that has modded old head to fit the 8.1 but need more time to find out details. The more people tell me it can't be done makes me want to prove you all wrong! It will be awhile before this ever happens, I have to get all kinks figured out on paper first. Imagine an 8.1 that looks like a stock 454, that would be awesome.

[10sec.et]

once you get that swap figured out you should equip it with Direct Exhaust Injection

[dietzster]

Laugh if you want, I'll be passing you on the highway

[squeeezer]

sweeeeeeeeet

then this means i can put ls7 heads on my gen 1 small block



im also gona put on 1 sb2.2 head on my ecotec........it can be done .........right??????????

[Big Dave]

The 8.1 started with a clean sheet redesign using the tall deck dimension from the old BBC. They only share the dimension in terms of deck height. It has a different head bolt pattern (six instead of five), different piston configuration, different crankshaft. It is a brand new engine that does not use any common parts off of the old Mark IV, or Gen V-gen VI motors. You stand just as good a chance of bolting up a 409 head on that motor (don’t feel bad I felt the same way back when they changed all the "W" motor parts when they introduced the "new Mark IV" BBC too). No one cried when GM introduced the new Gen III small block, and the 8.1 is just a bigger version of that motor.

I am telling you that the only parts those two motors share in common is the oil filter. If you have a line on a cheap 8.1 Gen VII motor fine. Work with it. It will accept all of the modifications that the old carburetor equipped engines will. Port the heads to improve air flow. They now offer three, count them (3), non-stock cam grinds new this year that they did not have last year. Put your energies into reprograming the ECU to run with the new cam and ported heads to make a hot rod out of your 8.1liter (496 cid) motor.

Big Dave

[dietzster]

Here I told you it could be done and here's proof! An 8.1l with GEN 5/6 alum heads on it. I work on these truck everyday, I know what I'm talking about, you guys have no idea so you say it won't work. From some of the other posts I've read on this site some of you guys clearly have no clue what you're talking about but will be the first to speak up and spout off specs and casting #'s and part #'s that aren't even close, and shoot down someone else's good idea. I was right and you were wrong so all of you can eat your words!

Here's the link.
http://www.highperformancetrucks.com/trucks/truck_view.php?id=162

[Big Dave]

Now that you have proven us wrong please keep us posted on how your build goes.

You will discover that that truck was a demonstrator; one of a kind made for a presentation, and that the 8.1 block that they used was in fact a Gen VI 454 block bored 0.060" over with a 4.25" stroker crank (which for some reason does indeed equal 8.1 liters).

You have the short block and the heads I am interested in hearing how it goes. Just be sure to check for water in the oil before you crank it up because the Vortec 8.1 is a reverse flow motor, the cooling passages do not align and you will get water leaks internally. Would not want you to wipe a bearing (to get an idea look at the head gasket for a Vortec 8.1 and compare it to a Gen V-Gen VI.). Because the 8.1 is a tall deck you will have to use a tall deck intake manifold (or adapter plates) and a special length distributor as well. Good luck!

Big Dave

[dietzster]

Case in point.....
OK, we'll have to agree to disagree. But I don't see them say 454 stroker anywhere in the article but they do say "the new 8.1L"
a few times, and "this is the first hotrod installment of the new 8100 big block motor"

[beersngars]

[dietzster]

Oh no, I missed the "e" on the end of site. Well disreguard everything I've said, 'cause it's obviously BS.

[10sec.et]

troll

[squeeezer]

i did find out the roller cams out of the 502 crate engines are interchangeable with the 8100 engine however the firing order is different