502 MPI Problem
 

Long time reader just join as most do when we have problems with that said here a little about me.
· Working at the same company for 37 yrs – Logistics supply chain services
· Live in Dallas area
· Age 59
· Have a 70 Cuda FC7 matching numbers
· 2013 HD with 2300 mile (for sale)

· And my problem toy, 1996 Advantage Victory 27 with 502 MPI (black motor) ser# 2000017 with VST tank system, MSD disty with MSD coil, had injectors cleaned (sonic cleaning) at time of valve job.

So here my issue: I bought this boat about 3 yrs ago, never seem to run right so had a shop do leak down test, found bad 2 valve guides bad. So we pulled the heads and had Kim Barr do a valve job. Seemed better but still not right. So I bought the Rinda scanner last week, hook up the scanner showed a knock sensor fault, new knock sensor clear the code out, Now it will run up over 4000 rpm but then oil started coming out the dipstick tube. This is after about 10hrs on the motor after the heads have been rebuilt. My plan is to do a compression check, then leak down, and use a scope to look in cylinders. I’m also going to change the oil and see what it looks like. So am I looking at blow by or can something else cause this I’m going to check all of the routing for the PVC system.

Regards,

PS: If I do find out its blow by rebuild or by a short block?

never seen the boat but I am local and surely can work on it. I would have to fit this in somehow as I am weeks out in repairs and the heat is a huge factor in DFW.

taking many breaks these days with this heat.

Your engine serial number posted is not close to being any form of a Mercruiser engine serial number Just a saying

Thanks BUP once I get these test done I may need to get with you, hope to do these test Thur-Friday in the 105 heat :)

Regards,

Could it be SER# OK200017 maybe an extra 0

zero K

0K for the first 2 engine serial number ---- yes I can run it to check on it. The VST a huge issue to keep that in the mix.

Whom did the injectors just seeing ?

Build sheets and any dyno reports ??

Our area not the greatest for high performance MARINE engine builds and machine work. Reyer and morrison good but they can careless about the one or two marine builds Just saying

Injectors where sent to someone in New Orleans area not sue who, no dyno report just flow report on the injectors. I keep the boat at Lake Texoma so Chad at Flowing Wells is the mechanic he removed the heads and re-stalled them. Also did a complete rebuild on the VST when I got the boat, fule pressue is good check that show no code after running it on Saturdat just oil coming out the dipstick tube, scanner shows temps good and everything within the correct readings.

https://www.offshoreonly.com/forums/...tick-tube.html.

crank case pressure to high ??

poor windage

poor oil control

oil whipping on and around the crankshaft

poor pvc and or crank venting or restrictions

So after compression check 4 cylinders are down 2 at 55-60, so looking for a motor I found this opinions welcome.
TRI STAR ENGINES & TRANSMISSIONS

PRO STAR™ MARINE 540 CID BIG BLOCK CHEVY CRATE ENGINE (COMPLETE & DYNO'D)
• Marine Build
• Dart™ Big M Block
• Dart™ Pro 1 Cylinder Heads
• 600 Horsepower
• 610 Torque
supplied with 2618 forged pistons, 4340 H-Beam rods and a Scat 4340 forged crank.
Dart™ Big M
290° Intake
296° Exhaust
237° Intake
243° Exhaust
.634 Intake
.640 Exhaust
Dart™ Pro 1 Cylinder head castings

Specs
►325cc Intake Runner
►121cc combustion chamber volume
►2.25 stainless intake valves
►1.88 stainless exhaust valves
►Rectangular intake port shape
►Howards HP valve springs
►Howards chrome moly valve spring retainer
•Dart aluminum heads are cast from virgin 355-T61 aerospace alloy for superior strength and integrity.
►Manganese bronze valve guides extend cylinder head life and reduce stem wear.
►Hardened exhaust seats are compatible with unleaded gasoline
►Multi-angle intake seats and radiused exhaust seats dramatically increase airflow.
►Spark plug holes are machined for gasketed 3/4" reach plugs.
►Heart shaped 121cc chambers improve combustion efficiency.
►Raised spark plug location improves flame travel for a quicker, more complete burn, producing more power.
►Exhaust ports raised .300" to improve flow
• Dyno Tested
Online price:
$11,995.00

Never heard of them, but that seems like a very low price for a carb to pan 540 with Dart heads.
I really don't know how they can make any money at that price with parts they have listed.

I called Mercury to ask about my motor and talked to them about their re-main program, told me they didn't do the 502 Mag and to call Tri-Star, said that they supplied a lot of motors to dealers.....just not sure. Going to pull this motor and pull it apart and see whats the damage.

Regards

I seen this engine in person last year. Not that impressed. I have the dyno sheet and build sheet. They could not tell me the compression ratio and if it was an internal balanced engine. They could tell me the name of the harmonic balancer either. I do not know what machine work was checked and or done on the block and heads. I do not see for that price this being a hard core marine speced build. The price last year was less as well.

How old is that link it now shows: Online price:
$11,995.00
OK found it, but that's not a marine so can it work or is the few $$ for the Pro540FCDM vs Pro540CD

Marine is 1k more https://www.tristarengines.com/perfo...-marine-series

Well got the motor out and number 5 had a piece of piston missing so it's at the builder now (Kim Barr) and looking at suggestions on which way to go. I will have the short block done with new pistons keep the crank and then looking at cam, alum heads and Holley EFI Dominator system, not sure about the distributor.
So my question is with so many different heads not sure what will be the best. I was looking at using the Crane 731 or 741 cam, so with that said what is the best combo for intake, heads ( brand and runners), dist, I have Imco powerflow for exhaust.

Regards & thanks

If your going with aluminum heads then suggest adding a closed cooling system if it does not have it on already

I what to send a big thanks out to Bob at Marine Kinetics, I called him and he took the time to talk to me about my engine build, very nice guy and is willing to talk to my engine builder to get it right.

Thank you Bob.

Regards

Steve

Update: The 502 is now a 515
JE pistons 9.5-1
H-beam rods (stock stroke)
AFR 305 heads - anodized
Victory JR port matched to heads
Comp roller rockers
168731 cam
new oil cooler
new coupler
Eddie Young modified riser for 02 and AFR gauge
Thermostatic control oil adapter
new FST water/fuel sepreator
Remote oil filter ( all line for oil are -12an lines)
Running Imco powerflow

Any guess on HP as it should be on the dyno Saturday , motor built by Kim Barr Racing engines

Rgards

Almost therehttps://cimg0.ibsrv.net/gimg/www.off...4fbc298583.jpg

565 with the 731, 600 with the 741.

Ok ready to go on the dyno tomorrow what can someone recommend for spark plugs?

he 502 is now a 515
JE pistons 9.5-1
H-beam rods (stock stroke)
AFR 305 heads - anodized
Victory JR port matched to heads
Comp roller rockers
168731 cam
new oil cooler
new coupler
Eddie Young modified riser for 02 and AFR gauge
Thermostatic control oil adapter
new FST water/fuel sepreator
Remote oil filter ( all line for oil are -12an lines)
Running Imco powerflow

ttt

you need a long reach plug for those heads, I ran those on my 540's NGK R5671A-7 will work for a starting point, what carb or TB efi is going on these.

Mine was tuned with NGK V power 7 if I remember correctly.

Thanks I'm going to use the Holley Sniper 800 cfm

Well made the 1st pull today, 548 hp / 576 torque @ 5000, need to add more fuel but so far everything looks good.

Nice numbers. Curious on ballpark what a build like this costs?

With new JE pistons, and AFR heads H-beam rods, ported intake Victor Jr, balanced, cam, basically only used the block & crank, with dyno time right at 11k

Regards,

Well did 2 pulls today up to 5300 rpm, 563 hp 587 tq :ernaehrung004:

Made 2 more pulls today, added a 850 cfm had 750 on it, 581 hp @ 5300 with 605 tq (weather was raining so not sure how this effect numbers)

Regards