compression question

**hillbilly68** · 07-05-2009, 01:37 PM

ok guys I got one for yall,
I got a 1973 Wriedt with a 460 BB in it, and i was runing wide open accross the lake bout 7am when the water was like glass, and then all of a sudden the engine ran hot and shut down on me, it wouldnt even turn over so i let it set for bout 45 minutes to let it air cool then hooked my bilge pump to it and run water through the engine to get it cool, fired it up drove it back to dock, brought it home and did a compression check one side of engine (all 4 cylinders) is runing 125 lbs of compression, the other side 1 cylinder 75 lbs other 3 cylinders 55 lbs, no water in oil and spark plugs are clean (no oil on them) so is it a head problem? or a cylinder problem? if it was a cylinder wouldnt my plugs have oil on them? and if it was a head problem wouldnt I have water in my oil?

any help would be greatfull

**pump squirt & BAIL!** · 07-05-2009, 01:53 PM

Sounds like blown head gasket! Between cylinders.

**GT Jets** · 07-05-2009, 01:55 PM

I would be willing to bet you have a blown head gasket in the low head, also, did you have the throttle butterflies 100% open when you did the test?. Could be giving you some bad #'s otherwise.

Good luck!

GT

**hillbilly68** · 07-05-2009, 02:24 PM

forgot to mention that there's some blow by on the vent in the valve covers....blown head gasket would be great, i was thinking the worse....... no i didnt hav the butterflies open whe i did it but i"ll try it..........thanks

will it hurt to finish out the summer like it is or does it need replaced asap????????????

**Richard Till** · 07-05-2009, 03:18 PM

A.S.A.P. or sooner. Period. With 4 weak cylinders on one side theres something major going on. You`ll be lucky if its just a head gasket.

**hillbilly68** · 07-05-2009, 03:28 PM

what do you think it is, richard?

**Sleeper CP** · 07-05-2009, 03:46 PM

Originally Posted by hillbilly68

ok guys I got one for yall,
I got a 1973 Wriedt with a 460 BB in it, and i was runing wide open accross the lake bout 7am when the water was like glass, and then all of a sudden the engine ran hot and shut down on me,

While it's apart check the pin in the dizzy to make sure it's not sheared or at least started to shear. When they let go in the boat the ignition retards the exhaust gets hot as hell, the engine shuts down and it won't start.

So check it out while you're working on things. Your compression loss is a much bigger problem

S CP

**1975sleekcraft** · 07-05-2009, 06:06 PM

i recently had a similar deal, but mine hit 0 compression on a couple cylinders!!

i am just wondering if yours could be partially tuliped?????

if your taking the heads off anyway, make sure your valves are alright!!

**hillbilly68** · 07-05-2009, 07:12 PM

it still runs good, i couldnt tell that there was low compression till i did the check

**SS 201** · 07-06-2009, 04:35 AM

I would take it apart and change bearings,rings, etc while it still runs. Save yourself some major problems. 460 Ty's don't like over heating let alone seizing.
I would bet that parts are crystallized from that ride.

**hillbilly68** · 07-07-2009, 03:44 PM

pulled spark plug and put 120 lbs air pressure into it and it held, no air coming from valve cover so i know the rings are good, i pulled the head off and found the head gasket does have a couple bad places in it, so, hopefully that was my problem, previous owner used a normal head gasket, i going to put a high dollar marine gasket in and see if that wont fix it...........

**058** · 07-07-2009, 07:40 PM

Originally Posted by hillbilly68

pulled spark plug and put 120 lbs air pressure into it and it held, no air coming from valve cover so i know the rings are good, i pulled the head off and found the head gasket does have a couple bad places in it, so, hopefully that was my problem, previous owner used a normal head gasket, i going to put a high dollar marine gasket in and see if that wont fix it...........

Have the heads surfaced before installing the new head gaskets. If it got hot there is a good chance the heads are warped and if you just change gaskets only you will be changing them again very soon.

**Jetaholic** · 07-07-2009, 08:03 PM

Originally Posted by Sleeper CP

While it's apart check the pin in the dizzy to make sure it's not sheared or at least started to shear. When they let go in the boat the ignition retards the exhaust gets hot as hell, the engine shuts down and it won't start.

So check it out while you're working on things. Your compression loss is a much bigger problem

S CP

This post is useless without charts!

**hillbilly68** · 07-25-2009, 06:06 PM

well guys, got the heads pulled off and the side with low compression found 2 cracks and a seat that was fixing to fall out, 1 crack (between intake valve and exhaust valve was a minor one that could be repaired but when we saw the 2nd crack its beyond repair (another boat anchor) so i found some heads on ebay (cheap) and a buddy of mine owns a head shop and i handed them over to him, did a valve job and worked them over a lil hint hint...... got it put together today and it sounds sweet so looks like yall going to have to put up with me at okmulgee cause I'll be there now...................

Thread:
compression question

LinkBack

Thread Tools

Display