Some of you know of the issue I had with the new engine I purchased recently. See post "Bad day at the dyno".

Just to update everyone on the progress. I went ahead and had my local engine builder tear down the "new" engine and give it a good going over. It appears it had cast rings, the bearings (rod and main's) were wearing uneven and the pistons were cast not Hyperutectic. The heads did not have the large valves and were starting to "Tulip" and the cam was different than described.

I went ahead and had my local engine guy fix this mess and get my compression ratio up from the 7.2:1 that it was to a ratio that could make some power.

To fix things I had him replace the heads with the closed chambered one's I had laying around. He had to line hone and deck the block, he reworked the rods, replaced the rings, bearings, and gaskets. He had to trim the intake .060 to get it to fit flush after the decking.

This took my compression ratio up to 9.2:1. He ran it on the dyno and this time it hit 434HP and 471 LB torque. Check out the links below to see the dyno sheets. The first one is the engine as first bought, the second is after changing the valve springs and the third is the final after all of the work described above was done.

Once again I want to thank everyone for the advice on the last thread. I should not have a problem with this engine spinning the tires :D

http://www.67chevelless.com/images/dyno/dyno1.gif
http://www.67chevelless.com/images/dyno/dyno2.gif
http://www.67chevelless.com/images/dyno/dyno3.gif

Steve

I,m glad you goals were abtained even though it certantly was the hard way,it,s just a shame you didn,t get what you paid for the first time around! graemlins/waving.gif

Steve, congrats on turning things around! I'll bet your local engine builder has many stories just like yours to tell - a lot of people who buy the low cost mail order "puppy mill" engines never dyno them, so they never know the power they are missing out on.

Now you need to take it down to the track and have some fun smile.gif

Thomas

Steve,
Glad to hear you got it turned around. Sounds like a hard lesson to learn. Let us know how it runs at the track. Looks like you have some decent power now!

Sorry you had to pay for two motors! Lesson learned. :mad:

Sounds like you have some nice power there with the finished product.

on the dyno what if anything did you have hooked up for accy's? was that dynoed with a factory type water pump. wondering if you had anything being driven off the crank. and what about the induction was there an aircleaner on there or just open carb?was there any kind of an exhaust system? or just open 2" headers?

did the guy at the shop have anything to say about some of the power dips in the dyno results were you lost hp and torque for a few hundred rpms then gain some of them back.....specially on the top end. were it took a dive then shot out a peak number on the hp.

i ran your combo on my computer dyno and got very similar results as you got........... pretty darn close.

it showed peak of 436 hp at 6000 rpms and 442 tq at 4500...........this is my first time to see the computer program being alittle on the low side thru out the entire rpm range........your motor was anywhere from 10 to 20 hp more in the lower range and about the same 10 to 20 ft lbs for torque higher then the program.

i have in the past have thrown belts going down the 1/4 mile and i knew i did because the car would get such a extra blast of power and put you back in your seat and the rpms would rev faster.and it would show up on my time slips as i would have 2-3 more mph and drop in e.t.

i have found those stock style water pumps really drag the motor down in the higher rpms specially around 5000 rpms and up when im turning my bbc's to 7000 rpms.........

Dennis,

I think you hit it on the head again. There were no accy's on the engine while it was on the dyno. He used an electric waterpump. As for the exaust, he had the headers connected to 6" pipes that went into the ceiling. So I dont think there were mufflers on it.

I have not talked to him about the dip in HP/TQ.

I have the engine in my 69 Camaro now but I plan to replace that stock water pump with a good electric one with an electric fan in the future. Can't do anything about the alt. and Power Steering Pump though.

That's cool that the dyno showed pretty close to what it actually was. I have Dyno2000 and got pretty much the same results. I think it gets a bad rap on this board but at least for me it's pretty accurate.

Thanks,

Steve

Steve, excellent! And it goes to show how valuable and knowledgable and "correctly priced" machine shop really is. I personally would never buy a crate.

I agree... what is up (or how much did you guys look into) that big dip from 5000-5600? With your hp peak 434 @ 5700 that dip will really hurt preformance and times at the track if you race. That should really be the sweet spot for you engine. But don't mean to drag ya down... just something you may want to look into before it goes into the car. Overall those are nice number for a pump gas 396 graemlins/thumbsup.gif