Well I am always searching for why my motor doesn't push out the HP it was advertised to. Sooooo.... I have a pic of it with the heads off



No idea if that even helps at all. Or if I can measure something on my block right now to detrmine if there was any 0 decking going on. I can't get in touch with my engine builder. He disapeared. Sux. Good thing is that the motor has help togeather perfectly and is still a great bottom end being all forged with Al heads. It is a 386. Figure I would make more HP than the kit wanted since it said it was for a 383. But I am 100 short.

I kinda think that the comp. ratio might be too low. I have no way of checking this though. I have yet to do a leakdown test, but I have done it on just one cylinder to see if I could do it and it passed with flying colors. So I dunno what to do now.


Think I should just give it to a more PRO- dyno tunning place and see how much they can get out of her?

 

If #'s 4 & 7 are at TDC, it definitely wasn't zero-decked.

The best way is to measure it while the heads are off.

 

Yea, that picture is only valuable if its at TDC... which it may not be. It might be a few degrees before, or after, which would explain the distance down from the deck. Looking at the serial pad though, I'm gonna say no. It looks to me like that area is not clean/machined so its not zero, but stock. Can you read any ID numbers there? Its the flat area in front of the passenger head.

 

You are going to have to put a straight edge on the deck, turn the crank, and measure (with a feeler guage) the closest the piston gets to the straight edge. Measure at the center of the piston because the piston will rock back and forth. The largest feeler you can get in between when the piston is at top dead center, is you deck height. If the block is not square, you may get different reading from corner to corner. Best to measure all four corners and average. If you want to measure your compression ratio accurately, you need to measure your chambers also. (plexiglass, syringe, colored alcohol).
ARN

 

I really don't think they pistons are at TDC
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I am 100% aware of all the ways to do it if the motor was open. Plexi, straight edge, feelers and all....

I was just wondering if there is was any old trick that people knew. I guess from the responses, there isn't.

I want to know if my lack of power is coming from low compresstion. I guess the only way to know is to open the motor.

I have about a grand to toss at it. I was thinking maybe they can pop off the heads, and measure for me. Only way I would be able to raise the comp would be maching the heads though. Not the best idea in my eyes. Cuz I am def not pulling the motor to get it decked now with less than 4000 miles on the clock.


Oh well. bad news for me. How much does it cost to have heads chaved down a bit and a thinner head gasket installed?

 

The only way to zero deck the block is to assemble and disassemble the engine a couple of times.

Block gets a light decking to make sure it's square. Cylinders get bored, mains get line honed etc. Engine is cleaned and assembled to measure how far the pistons sit inside the cylinders. Engine gets stripped down again and the remaining amount gets taken off the deck.

I doubt that your pistons being about .035 into the cylinders are losing you 100 hp. The 3 extra CID isn't going to make a big difference. The HP rating of the kit is always flywheel HP. Unless you put the engine itself on a dyno to see what exactly it makes, you'll never see that much power getting to the wheels. 100 HP loss to the wheels may be close to normal. Depends a lot on the drivetrain. Altitude and air conditions also affect how much power an engine makes. Technically my engine would put about 750hp to the wheels if I had it on a chassis dyno and got a corrected number. Because I race at altitude, I'm only getting about 650hp.

As mentioned above, check the pad in front of the right head. If the suffix and date numbers as well as the original vehicles last part of the VIN number are visible then the block has never been decked. Decking a block will shave off these numbers.

 

I will take a very close look. I only have given it a quick glance. I know the little pad there was coated in some sort of black paint kind of stuff. Looks like a protector. Either way I will check. thanks for all the help. Maybe my #s don't suck as bad as I think they do.