Engine mounts / stringer spacing
 

What type BBC motor mounts do you guys suggest installing for a single Bravo installation in a 27' sport? Also, what spacing between the stringers would be best? I think the stinger spacing will be partly determined by the engine mounts. Typically, I have seen 24" - 28" stringer spacing. How about the height of the engine stringers? Any advice with the particulars would be greatly appreciated. Pictures? Thanks in advance. Bill

Go back to page 9,twin to single question. This is how i did Vixen. Mel

Mel,
Thanks! You went with a 33" spacing to accomodate the Merc racing mount. How do you fine adjust the engine height alignment on a solid mount like that for the Bravo drive? Bill

Bill,you don't fine tune it,you install it right the first time and you won't ever have a problem.We set it up using a old mark 4 454 block,with the crank,flywheel,,coupler and bell housing in it so we had room to work on the front mounts once the rear mounts were bolted down.After we got the front ware we wanted it we marked it on the stringers an bolted it in.We have used gen 5 gen 6,merlin 2 an 3 blocks an never had to change anything,always right on the money. Mel

Bill,just be sure you have everything centerd from the tran.assembly to the new stringers an don't get crazy with the X dimension.A 502 with the right X an the right prop will make you a solid 70 +mph boat. Mel

Mel,
Thanks for the information. I was always concerned about installing a race solid mount since I figured it had to be perfectly aligned the first time or there would be problems. I will reconsider it now. I am thinking about a 540 for power at this point with a Bravo III drive. What do you think would be the highest X I could do without worrying about cavitation? Bill

Bill,your right about it being installed perfect on the alignement,but then your done with it.I cant say about the Bravo 3,I never used one.I tried to come up with a X on Vixen that was between a race an pleasure set up because i knew in time i still wanted her for a pleasure boat an what i came up with was 16 an half an its perfect,no cavitation at all and at 70mph in a 90 degree turn it never broke loose no matter how tight you took it.I said a 502 an 16 an half on the X would give you a 70+mph.I'm running a 540 merlin,a Crane hyd.cam.10-1 pistons an 230 valves an Vixen will top out 82gps on a nice day. Mel

Mel,
The only reason I was thinking about using the Bravo III was to keep from having to install external steering. I am not so sure I can reach the same speeds with it compared to a Bravo drive though. Maybe someone has tried it for comparison? I tracked down a Merc racing mount since I like the fact that it really ties the stringers together and will be an easy in and out like you hinted once I install it perfectly. Did you install an external steering system? If so, what type? I am a big believer in listening to the advice of someone who has done things right - can you tell? lol. Bill

Bill,no matter what drive you use you need external steering to be on the safe side in a high performance boat.When things go wrong at 60mph an up peaple get hurt real fast so with ext.steering its just one less thing to worry about.The only thing we did right was the engine stringer set up,with everything we put Vixen thrue thats the one thing thats as solid today as when i built it in 2000.Also any good ext.system should be fine.I went with hyd.helm,no power. Mel

Bill,go back to page 15 an read 77 starfire freshening,a great thread to read if your working on a Mag. This boat is the same Mag that Jeff man 1000 is working on.