Stock LT1 with SFI is smooth...a thick washer will stand on it's edge while the engine is running. Have a look. I hope this video addresses reservations about a well done Chevy conversion. A proper Chevy conversion doesn't diminished the refinement.

 

Nice job. Looks like you've got it dialed in really nice. The Jag v12 is not without its detractors, but not many will challenge it on the basis of smoothness. The Jag engine will pass your washer on edge test (especially the pre-HE). It will go one further though. The stock v12 will keep the washer standing at 6000 rpm.

 

Isa:

Coool. My 83 XJ is powered by one that came out of a 94 Cadillac Fleetwood Brougham.
Not sure if it is as smooth as yours, but quite enough to suit me.

The induction system has never pleased me completely. I am running a K&N knock off
and it whooshes on acceleration. Not an issue to my ears. I used a bit of the Jag piping to make the connections to include the MAF.

One SMOG tech fussed a tad, but passed it!!!

What air box is that in yours and where does it get it's air. Someday
sometime, I'd like to change mine to ingest cooler air than it does now!!

Nice job. looks good, sounds good.... In my way of thinking, they make a great combination.

And, I would like to mess with a V12. But, now I am messing with a Tecumseh I1 in my new toy, a TroyBilt Tomahawk chipper shredder. I have work for it!!

Carl

 

Carl... I'm using the a factory xj6 air cleaner, the xj6 90 degree bend and three couplers. Its reasonably quiet. The paper filter acts like a muffler. You may be able to do the same. One way to totally quiet the intake is to add an intake venturi... thats the cone shaped device that Jag and other marks fitted in front of the air cleaner media. The Principle is that at the venturi point the air is accelerated faster than the speed of sound so no sound can escape. It's also makes choke point that limits performance.

 

I thought it looked familiar!!! I think I still have mine in the left overs that are still here.
But, it's plastic intake cone is busted I think, Not a rarity, I understand! Not going to look for a sound one. Just goes against my grain!!

So, yours is as mine is, breathing engine bay air, huh !

Oh well, if I don't put on my hearing aids, it is not displeasing and even with them on not a major issue.

Carl

 

To quiet the intake noise you need a resonator(helmholtze resonator) those are the tubes that factories put on the intake tube to quiet that whoosh or resonance in the the intake, mostly on full throttle when velocity is high. And the know the reason the washer stands up still on the v12? Cause its not moving....... lol

 

comon guys, a V12 is about the talk and not the walk!

something like" mines is bigger than yours"

 

I admire a well done conversion and applaud the mechanical skill needed to get it running so well. I just like seeing what good mechanics have done. Sometimes I learn something.

 

Brutal:

Yeah, the resonators came with my package. I removed the two as I recall. One was a triangular thing that fit right over the intake manifold and was plumbed into the angle duct just before the throttle body. It went to create the space needed for my PCM, suspended from the wing braces. And, to expose both unit's nice alloys. I've a Cadill emblem to insert on the plug I made.

I did use the flex duct from the XJ6 to complete the ducting. It was just right!!

So as not to excite the original SMOG referee, I cobbled a box that looks GM for the filter!! And plumbed in a carbon canister in the engine bay even if an identical one dwells behind the RF lamp. Just make it look GM was my mantra!!

Carl

 

YUP! i agree, gotta love GM. owned many of there stuff.

i use a lot of GM sensors and parts on my V12, lot cheaper and easy to get,compared to JAG.