Mercury Marine plant question

[LGAFF]

He was happy to see people still care about the LT-5.....I was thinking maybe we can put up a mercury marine section, and let the former workers post about their experiences. Asked him if I could give him a call.


Glad to hear someone still has interest in the LT-5 Vetts. I was the orginal development dyno operator for the program 88-91 at the Mercruiser plant.
What would you like to know?

[JThomas]

Very interesting Cliff Hanger!

[XfireZ51]

Originally Posted by LGAFF

He was happy to see people still care about the LT-5.....I was thinking maybe we can put up a mercury marine section, and let the former workers post about their experiences. Asked him if I could give him a call.


Glad to hear someone still has interest in the LT-5 Vetts. I was the orginal development dyno operator for the program 88-91 at the Mercruiser plant.
What would you like to know?

Lee,

That's a super idea. We could have a Legacy Forum with these people providing their own stories from their participation in the ZR-1 project.

[LGAFF]

Got another E-mail, a section I think would be pretty cool:


I can help you out I was the lead-man/repair technician in the assembly area from start to finish of the project Send e-mail back or call me after 4PM

I checked Heart of the Beast, this guy is in the book

[tomtom72]

I think an MM section is a cool idea. Man Lee, you are like the electric company....you have connections all over the place!

[LGAFF]

Going to call this guy today, any specific questions you gus would like to know?

[Blue Flame Restorations]

I'd be interested in anything proto or pre-production. The earliest Phase motors.

[scholtmj]

Looks like I'm a little late, but if you're talking to the dyno operator you should ask about the numbers LT5's put out at Mercury vs. advertised power numbers. I'd be curious if he remembered any that had big numbers or were dyno dogs.

[xlr8nflorida]

Originally Posted by scholtmj

Looks like I'm a little late, but if you're talking to the dyno operator you should ask about the numbers LT5's put out at Mercury vs. advertised power numbers. I'd be curious if he remembered any that had big numbers or were dyno dogs.

Agree 100%

[LGAFF]

Here's some of our discussion:

1)Dyno numbers....varied from 350hp to 400hp on the early motors, most of this had to do with ring seal/break in.....they said it takes 10-15K before a motor really was broken in and rings seated. GM has a % guideline that is accepted from engine to engine.

-He said compression was 210 pre break in but was well into the mid to upper 200s after break in

-Cam timing issue was also discussed

2)Early rings were a problem with blow by, 93-95 rings fixed that issues
-He mentioned if you used Mobile 1 to break in the engine, there seemed to be issues...regular oil seemed to be better in the first 15K miles.

-Also talked about Lotus not using exhaust valve seals
**It really seems that there were differences in opinion between the Lotus engineers and the guys at MM who had practical experience.
There is a bigger story to be told than what is in the HOB,

3)Cam shaft failures....more to it than someone at the plant over revving the motor....there was nearly "0" clearance on the cams, creating an oiling issues...this was fixed....many of the spare motors floating around were the motors with cam clearance issues.

4)The reason for the 8K RPM is not the chains, its the oil pan which would pressurize the motor, pushing all of the oil to the top of the motor, leading to overheating of bearings....7600rpm is the top sustained RPM.....attempts at 8K melted the bearings on some motors.

5)They did a "progressive" porting test starting at the air horn and recorded results as they moved throught the TB, Plenum, heads, etc. He has these recorded somewhere.

6)The oiling system actually creates a vacuum below 4500 and above 4500 it starts pushing everything to the top half of the motor, i will get more info on this

7)They did a lot of cam timing and cam testing on cars, they evenbuilt 3 race motors with solid lifter cams.

8)Apparently they too ruined a few heads porting them, to solve the issue they cut a few open to see where the ports were in relation to the cooling and oiling passages.

9)Only thing left over at the factory at this point is the dyno panels...the actual dynos are gone.

10)Still people with spare parts out there, DIS modules,prototype parts, etc.

11)There is no agreement with MM staff that prohibits them from discussing

12)He recalled 30 thou was the most a head could be milled, more than that allowed the chain to come loose.

12)I invited him to visit the registry and will be calling him back to do a more formal interview....he said he got out his thunder at stillwater tape and watched it after my note....you can really hear the passion these people have in their job. He told me he is not sure if he will visit the forum as there are alot of Chefs in the kitchen out there and it irritates him to hear people talk about things they really don't understand.