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"New" Engine Very Low on power

Thanks for all the replies guys. Actually with my leak down tests showing 2 cylinders above 20%, one caused by bad valve seat..(#5), I figured this old bottom end could use freshened up while I had it down this far.

I decided to hone, install new rings, and bearings. When torquing the rod caps, one broke. It appeared like it was already cracked as it broke without much effort... This was cylinder #5...

I purchased ARP rod bolts and sent the motor to my machine shop to have them installed properly (re-size rod ends). I debated on installing them myself as it probably would have 'worked'. This would be a good chance just to have them look over the bottom end, especially piston-cylinder wall clearance, which I was worried could be excessive.

ezstriper: I have the cam out and it appears fine, just by eye.. I'm not sure if my 'stainless marine' manifolds have a spot for an O2 sensor or not.

Gimme Fuel: I didn't run 39* timing for long, it was more of testing and tuning. It was set back to 36*. I didn't have a problem with reversion until the lifter broke and wasn't firing on one cylinder, so there was reversion on one side.

Skip7750: I did check cam installation with a dial indicator after it was installed by a method told to me by the machine shop.. of which I forget by now. But it checked out okay. I forget what length pushrods I ordered, but I measured first and then ordered.

The motor actually seemed to run good, just lack of power on top end, getting worse going up or down in jet size. Until the lifter broke.

Jimway:
With the issues with the #5 rod bolts is it possible it made valve contact without bending the valve and still screw up the seat?
 
My pushrod lengths are 8.650 and 9.350 in. They are Trick Flow 3/8 pushrods. I did measure for these. My rockers are just the standard 1.7 stamped steel long slot ball rockers, JEGS Part Number: 809-12368085.

The valve seat was fixed under warranty by the machine shop ( Oaks Machine out of Logan, Ohio ). Always had best of luck with them and so has my dad for years and years. They did confirm the seat was bad and the valve was not bent.
 
Alright guys, I don't want to leave you all hangin' so:

Now that this engine has been at the machine shop for 'just rod bolts', after my own hone job it appears the cylinder walls really do need some more cleaning up and they are already 'too' loose at around .008-.009 clearance on the walls. This was something I had him look at as it was a concern of mine anyway.

After discussion with the machine shop I'm building a fresh .030 454 (460). He has a set of shortly used popup speed pro .030 pistons and a 454 crank that he is turning down that he sold to me for $300 +$120 to turn down the crank. We traded my rods for his rods that are currently on the speed pro pistons to avoid needing to re-balance them. His rods also have ARP bolts in them. I basically got the rod bolts installed for free. This short block will cost me less that $1500 including all machine work.

I'm still going to use my same cam and will buy a new set of compcam lifters.

This should give me a good boost over my old 330 Mercruiser. I'd like to see 72mph out of my 24' Enforcer with this setup, I don't think I'm being overly enthusiastic. This would be a 10mph gain over my old peanut head stocker. Anyone else have something similar?
 
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I got the short block back from the machine shop some time ago, I've since painted the block and installed the heads.

BTW the paint I used is GM code 20 from 1981. This is supposedly the same paint used for mercury racing blue, let me know what you think.

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While I'm at it here is a picture of the new pistons and some exhaust tips I bought and sanded/polished up over winter, it's kindof a before and after pic.

The exhaust tips I got for $100 on ebay, I'm not sure if I'll use them or not. They are GIL tips with the spiral baffles in them. How restrictive are these? I bought them because my current GIL tips have the flappers blown out of them and was looking for something that I wouldn't have to worry about water coming back up the exhaust.

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Not sure if anyone finds the huge pictures annoying or not.
 
JeffCh48 said:
BTW the paint I used is GM code 20 from 1981. This is supposedly the same paint used for mercury racing blue, let me know what you think.

Not sure if anyone finds the huge pictures annoying or not.
Click to expand...

Pretty. I don't mind the big pics, but I've got a 17" laptop and 4-23" LED monitors on my desktop.....:D
 
Howdy,

I have 1988 Enforcer, I am looking to get some more speed out of my Stock Engine, I think its a 385 HP. Can you give me a ball park of what this has costed you to get that speed. I dont know if Im going to just use her this season and get a larger faster one next year or if I should put the money into this one.

Thanks for any info you can get back to me with. I am assuming we had similar engines.

Joe
 
Well.. The best speed I have gotten is 63mph with a 24p 4blade, but that is with the original 330hp with no modifications. After putting on the intake and exhaust from my 'failed 427 build' I didn't gain anything.

I will let everyone know what I get out of this motor when it is finally in the boat and running for the first time.. hopefully in the coming weeks.

What kind of speeds are you getting out of you Enforcer with the 385hp Mag motor?


Also, larger boats generally take more HP to move the same speed.. food for thought.
 
JeffCh48 said:
Well.. The best speed I have gotten is 63mph with a 24p 4blade, but that is with the original 330hp with no modifications. After putting on the intake and exhaust from my 'failed 427 build' I didn't gain anything.

I will let everyone know what I get out of this motor when it is finally in the boat and running for the first time.. hopefully in the coming weeks.

What kind of speeds are you getting out of you Enforcer with the 385hp Mag motor?


Also, larger boats generally take more HP to move the same speed.. food for thought.
Click to expand...

After some prop problems last year, that were fixed over the winter, I got to take it for a lake test a couple of weekends ago on lake michigan.
same as last year 59-61. But the lake was quite choppy, 2-3 ft waves.

I have yet to take it on a Canal by the house where it is always calm.


Thanks
 
Hey Guys,
I've finally got the rebuilt engine in the boat. I've already broke in the cam.

I re-used the cam.. I bought new comp-cam lifters. I already broke in the cam and changed the oil to VR1. Seems like everything went just fine. I will see how it runs this weekend.

I bought a new gear reduced starter and new 105 amp alternator.
I'm making new 0awg battery cables and 4awg alternator wire. Also, upgrading my 8 year old group 34 battery to a new 31 size optima battery with a new Hardin Marine battery mount.

Earlier this year, when I had the stock engine, I had to use a jump box on my boat and it was fairly embarrassing and a hassle. My battery cables and battery are a bit overkill, but at least I won't have any issues starting it again!

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http://i938.photobucket.com/albums/ad222/jeffdeath48/Checkmate Enforcer/IMG_0788.jpg

Pictures of it in the boat, battery cables, etc.. to follow on a later post.
 
I am more than excited to finally be pulling the boat back to the Ohio River, last weekend didn't work out due to the terrible rains and flooding a couple days prior. I hope the river has cleaned up since.

Here are some pics of my new cable/ batter bracket setup. I figured I should shrink these pics down... because who wants a high res photo a a battery cable. I used the right crimp tool to make all my cables. In addition to what I said above, I ran 4awg to my power trim pump; the old ends were breaking and I had the extra cable so why not.

Hopefully I'll come back with a fast GPS number to give you guys. Thanks all.


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Be careful on the river this weekend. Water level is better but debri from WV storms is probably everywhere. What area of the river do you boat on?
 
We boat around Ravenswood, staying in that pool of water. We have a place we stay at near Racine, OH. Often boating down to Buffington Island for the day, sometimes to just below the next lock.

edit: There were a few things floating, but the water was pretty debris free all considering.


I actually went down Thursday and am glad I did, weather was beautiful Thus-Sat and started raining Sunday.

So, the engine ran great, however I was only able to get 62 out of it... Which means I have a net gain of 0 over the stock 454. I don't understand what is going on...

Then I had some rocker nuts back off. My plan is to buy a new set of nuts and 'double nut' the ones that stayed tight and readjust and double nut the two that come loose. One came so loose the rocker was turned sideways. I watched tach drop 400rpm's when this happened, the other rocker was only slightly loose. Anyone see a problem with the double nut approach as extra insurance? I don't want to pull the manifolds again to adjust another rocker.
 
JeffCh48 said:
We boat around Ravenswood, staying in that pool of water. We have a place we stay at near Racine, OH. Often boating down to Buffington Island for the day, sometimes to just below the next lock.

edit: There were a few things floating, but the water was pretty debris free all considering.


I actually went down Thursday and am glad I did, weather was beautiful Thus-Sat and started raining Sunday.

So, the engine ran great, however I was only able to get 62 out of it... Which means I have a net gain of 0 over the stock 454. I don't understand what is going on...

Then I had some rocker nuts back off. My plan is to buy a new set of nuts and 'double nut' the ones that stayed tight and readjust and double nut the two that come loose. One came so loose the rocker was turned sideways. I watched tach drop 400rpm's when this happened, the other rocker was only slightly loose. Anyone see a problem with the double nut approach as extra insurance? I don't want to pull the manifolds again to adjust another rocker.
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Do it right and get a proper set of polylocks. What do you have on it now? Send a pic of adjuster nuts. If they came with the roller rockers, there should be an allen set screw inside that you tighten once you have correct lash set with outer nut. Those will not looses unless something is way wrong.
 
I'm actually just running new long slot stamped rockers, they are official GM brand. The nut was visibly backed off, it was halfway up the stud, enough so the rocker was no longer in position; so no cam lobe problems on this one.

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I'm not so sure I could find poly locks to fit these rockers, or that they would fit under my valve covers
 
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Been a long time since I've been on here and randomly thought about this old thread.

What I ended up doing is:

I came across a junky boat for sale that my father had installed a 496 for the previous owner (had more money than sense). I purchased this boat for, if i recall, $2500. I pulled the engine, dropped my original stock 454 in it and sold the boat for a profit.

I put my carburetor on the motor, got the jetting mostly set. I'm hitting 74 mph now. I ran out of jet's and the summer ended before I could get a larger kit.

I still think come spring, with a set of larger jets on a cool day that I can hit the magic number of 75 mph. If I recall correctly, I'm now running a 27 pitch 3 blade prop to hit these numbers. The acceleration from a 30-40 mph cruize is insane.


I've even got a pretty decent spare engine now too. If I ever end up doing anything with it, I may need to consider new top end components to fix whatever power issues I was seeing.

Sorry for the long time without a resolution, but wanted to let everyone know this has ended great!
:popcorn:
 
weird on the other engine, should have made decent power, but like I said procomp heads known to be junk, did not pay attention to the cam you were using but I am betting your combination was off(heads/pistons/cam/intake-carb) also I noticed that you were using the low performance coupler on the engine...be careful with that, the HP ones use 6 bolts instead of the 3, good luck, Rob
 
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