Thunderbolt V rev limiter

[pwpns]

I have a 99 stingray 192rx cuddy with a 4.3L mercruiser that I just rebuilt. It has a cam that is rated to 5000 rpm along with the edelbrock manifold and carb but the manufacturers WOT is 4800 and I have read that the thunderbolt V has an overspeed limiter and i was wandering what it might be set at exactly. The box is listed as 4.3L/LH Alpha then under that a bar code then under that 861251-1 follows the serial number of the motor is OL338612. I was just wondering if I could take advantage of that extra 200rpms for prop selection or if the rev limiter was going to shut me down anyway. Thanks for any help you can offer me.

 

[John_S]

Re: Thunderbolt V rev limiter

Yes T5 has a rev limiter. It is internal to the module, and can not be adjusted. I believe Merc states it is 150-200 rpms over max rpm. Because a cam is rated to 5K rpms doesn't mean your boat will get there. Test your current prop before sellecting a new one, just based off theretical rpms.

 

[Bondo]

Re: Thunderbolt V rev limiter

Ayuh,... She'll tic along to 5 grand,... Ya still wanta prop up to the 4800rpm mark though...
Due to Conditions 'n all....

 

[pwpns]

Re: Thunderbolt V rev limiter

Thanks guys. The boat runs 4500rpms @ 48mph(gps) and I just ordered a 4 blade 21 pitch solas HR4 Rubex that should bring me up to the 4800rpm limit.

 

[John_S]

Re: Thunderbolt V rev limiter

Thanks guys. The boat runs 4500rpms @ 48mph(gps) and I just ordered a 4 blade 21 pitch solas HR4 Rubex that should bring me up to the 4800rpm limit.

So, you were running something in the 23" pitch or higher range?

 

[Tail_Gunner]

Re: Thunderbolt V rev limiter

So, you were running something in the 23" pitch or higher range?

http://forums.iboats.com/showthread.php?t=438442

He was running a 23p laser ss to 4500.....Wish you would have ordered the Baypro...But thats just splitting hairs.. and a inch of pitch...But with a 4bl and good intake that boat should turn 4800..How agressive is the cam??

 

[pwpns]

Re: Thunderbolt V rev limiter

tail gunner the cam is a comp cams 266HR 266/270 advertised duration 210/215 @.050 lift, .500 lift on intake and exhaust with a 112 LSA it is listed as a cam with good low and mid-range power. The reason I went with the solas is because I own a gun shop and one of my suppliers deals in fishing and a small amount of marine products ( I only knew this because of one of my many visits to my local boat store I seen their catalog on the parts desk so I asked my sale rep and she sent me their fishing/marine catalog) and they carry some of the solas brand props. They didn't have the Titan but they did have the HR4 rubex which is comparable to it with a flo -torque stlye hub which I got at a considerable savings to me.
Thanks to everyone for their expertise,knowledge and advice you have helped me considerably.