Just wondering. The HT383 uses what appears to be an elastomer damper. I just ifnished getting my motor assembled and have a pretty healthy cam in there...enough to make steam upwards of 7000 RPM. I'll use the damper now with care, but since I have an HT383 and the damper has a pretty healthy weight on it, if I could get a replacement performance damper like a fluidamper have it actually work fine, without vibration. This isn't balanced the same as a regular small block so I was kind of wondering. The weight is detachable from the damper, if it helps.

 

i'm not real clear on what you have, but if you have an internal balance you can use a fluid dampner made for an internal balance SBC with not problems. if you're engien is external balance (sounds to me like it is) the dampner would have to be for a external balance engine.

 

Sorry, should have been more specific. Most 350's are internal balance, and 383's external balance. My ht383 crate motor is external balance too. Problem is, that is uses a longer 3.8" stroke, so I dont know if just bolting on a damper for an external balance motor will work. I assume it wont.

In that case, can I have the new damper balanced the same as the old one that came off? Even though it has what appears to be a good damper on it, I dont trust anything other than a fluidamper over 6000 RPM.

 

Basically a fluidamper for a small block 400 motor should be same one you need for your engine. The 400 was the only externally balanced small block from the factory. Your 383 is basically a 350 with a 400 crank, so the balance should be the same with an externally balanced 400 damper.

 

No, my motor does not use a 400 crank. it is a 3.8" stroke crank and std. bore which is also a 383. That way I cannot use a 400 damper out of the box...

 

Shouldn't make a difference, external balance is external balance, doesn't matter how long the stroke is. A 400 fluidmapr (ext bal) will work on your HT383. To confuse you even more, 383's can be internally balanced, you just need the right crank...

 

Ahh! Good stuff. Learn something new everyday. Guess that leaves me open to upgrade to a fluidamper later on.

I know about the internal balance strokers. Bad ***. Next motor I build will probably be an internally balanced 6.0" rod 383 LT1, if the urge to do something awsome with me 400 block doesn't get to me first Thanks for the info.

 

You might want to check but I think some of the aftermaket dampener vendors sell a bolt-on counterwieght for their products to make it compatible with 383 strokers and 400s. Uses a couple of machine screws to bolt a counterwieght inside the standard (neutral balanced) bampener unit. Don't quote me on that.

I, personally, would not use an externally balanced engine up to 7000 RPMs except for short bursts (drag racing). For road racing or any extended high RPM use I'd always get it internally balanced.

 

I probably wont take it that high. my cam is good until 6500, which will be close to my shift point. I've seen some dampers with bolt-on counterweights. I'll have to look into that more. Doubt I'll see that kind of RPM anyway. You should have seen the crank...has 4 deep holes drilled in the rear counterweight. My machinist told me he could internally balance it, but it would cost some $$$, especially in mallory. $400 to balance? Might as well get another crank.