350 GM engine ID # and performance

[DonMerz]

I purchased a 1989 Reinell 215C OMC 350 260 HP a couple of months ago. I don't believe I am getting the performance I should get out of this boat and drive train. At WOT I am hitting 38 MPH at 3800 RPM with a 14.5 x 19 prop and 35 mph at 4100 rpm with a 15 x 17 prop.<br /><br />The block has been changed and it has a '79 Quadra Jet with a distributer with points and no visible vacuum line for advance? I am trying to Identify this engine to see what it's specs are. The ID# on the front shelf is V1117PHD. The V1117 is consistant with a 1987 block but I can't find reference to the PHD suffix anywhere. On the back of the block is the number 093638 which I am guessing has a 14 in front of it that I can't see which would be consistant with a '87 block. There is also the # K077 and GM 5.7 so I know I do have a 350 at least.<br /><br />Can anyone Identify the suffix PHD? or help out with what I should be getting for WOT rpm and mph? (maybe an approx anyway)<br /><br />Thanks,<br /><br />BigD

 

[QC]

Re: 350 GM engine ID # and performance

I am guessing your WOT should be between 4200 - 4600 RPM. Pretty consistent around that year model. Others will chime in soon. How are you getting your speed numbers? Only thing worth discussing is GPS or Radar . . . Also, verify the tach is correct. At what are you running this boat?<br /><br />Keep posting any info nuggets like you have done with the S/Ns etc. Propeller condition, bottom condition, load in the boat, altitude . . . Need to eliminate all of the boat factors to narrow in on whether or not this is an engine issue.

 

[DonMerz]

Re: 350 GM engine ID # and performance

Thanks Quietcat.<br />I'm getting the speed via GPS. Propeller is newly rebuilt SS, bottom is clean but has a slight concave area on starboard strake near the stern. It begins 26" forward of stern/transom and continues for 32" and is approx 1/8 inch deep in the central area. Pretty uniform. It doesn't seen to pull the boat one way or the other and the boat jumps up on plane quickly. Someone suggested it could be there to counteract prop torque. Never heard of such a thing but ?? The boat is very lightly loaded if you can call my 6' 4" 250 pounds light. Just a few fishing poles and a couple tackle boxes. Altitude is 6000'.<br /><br />A few minutes ago I was trying to run compression test but the connection nipples don't fit below the manifold. Guess that one will wait until tomorrow.

 

[Don S]

Re: 350 GM engine ID # and performance

If you bought the boat from "Lower" altitueds, you are probably going to have some problems.<br />Carbs need rejetted for the altitude, probably repropped and many times new gear ratio's in the drive if the prop changes can't make up the difference.

 

[DonMerz]

Re: 350 GM engine ID # and performance

I bought the boat from a location at about 5000'. The OMC Cobra outdrive is labeled High Altitude 1.59 Dropping from the 19P to a 17P changed from 3800rpm to 4100rpm and 38mph to 36mph. <br /><br />I just found a thread by a fella with a 1989 Glastron 22' that runs 58 at 4600rpm with a stock 350 and a 19P 3 blade. I don't know what the Glastron would weigh or altitude, but I think it would indicate that my 21' Reinell should do better than 38 at 3800rpm with the same prop.

 

[LuckyPenny]

Re: 350 GM engine ID # and performance

I maybe wrong but from what you indicated you have a 1977 Mercuriser 350 CID (5.7L). It is a point/Condenser setup.<br />As for the distributer, it does not have a vac advance, hense no vac line from the carb. if your distr does require a vac line, then that is your problem, not fully advancing. Also, if it is a marine carb there should be only one vac port and that is for the dashpot.<br /><br />It sound like you need a complete tune up. and make sure you do not have auto/marine mixed parts.

 

[DonMerz]

Re: 350 GM engine ID # and performance

Just returned from town where I purchased new plugs, coil, fuel pressure and vacuum guage amongst other items that I don't remember offhand. The points look brand new, so not replacing them.<br /><br />I'll let you all know what I find after installing everything and taking the boat for a spin.

 

[DonMerz]

Re: 350 GM engine ID # and performance

Luckypenny .. it's an OMC 350 1987 block with a '77 QuadraJet carb. It has a marine distributer, so no vacuum line required.<br /><br />Any ideas appreciated.

 

[QC]

Re: 350 GM engine ID # and performance

The guy with the Glastron is full of carp . . .<br /><br />I had a very light 20 footer with a TBI 5.7 and it saw 58 maybe once. Bullpuckey. Don't get sucked into that . . . I was running about 22 inch pitch at 4800 too. Uh uh, no waaaayyy.

 

[DonMerz]

Re: 350 GM engine ID # and performance

Installed all the new tune up parts and ran the boat on the lake today. Looks like I achieved another 200 RPM and 2 MPH at WOT. Not bad for a standard tune up with new plugs, wires, coil, filter. I also ran compression. left bank 105, 95, 95, 95. Right bank 105, 100, 100, 100. I just saw a post from Don S. with specs on this engine. According to that chart I am supposed to be in the 150 / 160 PSI range. Previous owner must have installed some funky heads?? With current compression all being in the 100 psi ball park, it has to be something that relates to all cylinders. <br /><br />What do ya think guys?<br /><br />QC .. thanks for debunking the Glastron post.

 

[imported_scott_m]

Re: 350 GM engine ID # and performance

Me thinks that is a tired motor. Or wrong heads, or extra thick head gaskets.<br /><br />Did you try to shoot a little oil down in the cylnders and running the test again? If your pressure goes up, likely culprit is worn rings.<br /><br />How did the plugs look? Next is probably a leak down test.

 

[Northern Eclipse]

Re: 350 GM engine ID # and performance

With those compression readings you now need to do a leakdown test, it could be as simple as needing to have heads redone do to worn valve seats and guides. Does motor use any oil?