dalynchmob

Mods in sig. I had my engine put in in 2008 in Fl and i'm now in TX i've put 35k on it since it was put in. From the day i picked it up in 08 it's had a slight up down wobble on the damper i figured it was a slightly bent ear on my stock crank hub. Recently put new heads, cam, intake, TB, and injectors on it. It was putting down 301 before the topend work and now it only puts down 352. I would have thought with my mods i'd be getting better power to the wheels. The guys that did the head work think my engine might be internally balanced and the guy that put the motor in in 2008 used the stock balanced flexplate and it's causing the engine to be out of balance and preventing max power. They suggested putting on a neutral balanced flexplate to see if the wobble goes away. It runs very well the way it is and i don't want to make matters worse by putting on a neutral plate.
Has anyone ever heard of of this?

Guest47904

If the guy was smart enough to balance an externally balanced engine, internally, he would be smart enough to know what flexplate to use. These "head" guys sound like Moe, Larry and Curly. The external balanced flexplate has a weight welded on it. To get it neutral, all you have to do remove the weight. Something that could be done in the car. HOWEVER you don't simply change one for the other even if ML&C say so.

But the flexplate is not causing your problem. An out of balance engine would shake your teeth out but not hold back the engine output much.

If your rotating assembly were out of balance enough to show up at the damper, it would be trashed entirely after 35K miles.

As far as the top end work goes, perhaps there's a mismatch of components. Something in the top end is not what it's supposed to be since Comp doesn't make a cam for a chevy that has 232/240 ???????? Elliott does but not Comp.

If it's actually the Elliott cam that is listed as 232/240 .578/.574 110 LSA then maybe it should have 1.5's. All the cam specs I've seen listed are with 1.5's but you have 1.6's. You have essentially made the lift numbers .617/.612. Not to mention you have changed the duration numbers. I would talk to Elliott if they were NOT the ones that told you to use the 1.6's.

Everyone goes to the bottom of the page on cam selection when they really should not. A more moderate lift is nearly always the way to go. By putting 1.6's on it, you've essentially "gone to the bottom of the page" but your bottom end can't handle it and it runs out of breath.

I'll put money on 1.5's giving you better numbers. While your at it, you may want to check the geometry if you haven't already.

dalynchmob

Thanks speedy. That's what i was thinking as far as it being out of balance that much, that it wouldn't have lasted this long or i atleast would feel it. But i don't it's so smooth but just hits a brick wall on the power producing.

It is an Elliot cam sorry for the cornfusion. I did email LE because i needed the specs and the email i got from him, copied and pasted, ".578/.574 with a 1.6 rocker."

I'm just gonna run it this way and start building me an LS motor i think. Or find a complete eng/trans from an LS car and do some work and swap it in. I've put so much money into this thing and it's just not producing what i want. The only shop i can find that works on LT1s enough for me to trust is 3 hrs away Thunder Racing

PA94Z

You're down about 60 horsepower from what typical LE2 M6 cars produce. Something is wrong somewhere in that combo. Was the cam degree'd in? Are the springs new and installed/matched to your cam? Those are a couple places to start.

<Puck>

What RPM did it peak at?

dalynchmob

5800ish.

<Puck>

With LE2 heads and that size cam you should be peaking much later then 5800.

Do you have the dyno graph? Any signs of valve float or maybe ignition issues?

MachinistOne

How about posting the build sheet with parts used and machining specs and tolerances, compression, cam degree, spring pressures, etc

Rob94hawk

I'd like to see the dyno tune sheet. With your heads/cam you should be hitting close to 400 to the wheels.