i am starting this thread for a coupld differant reasons
1 being i have mentioned some of this stuff on here before tings got confused
2 a differant thread i had started (about a head) started to go in this route so to get them on toppic i started a new on
a little background (or refresher) on the situtation. i bought my boat (1988 sunchaser 3.0 alpha 1 17' trihull deck style) in july of last year i was informed that it had a cracked block. i was hoping that it was just an external crack, but after "patching that up" rebuilding the carb and fresh oil in itwe took it to the lake. got it home only to find a milk shake looking stuff on the dip stick. changed oil again and and same isssue. had also noticed that it felt a little under powered when comming out of the hole noticed a litlf crank case ventaltation coming out of the vent tube on top of the valve cover. so i pilled the head to find the head gasket burned in 2 in between cylender 1 &2 an itwas busted between 2 & 3 upon looking thing over closely i found where the block was busted inbetween cylender # 1 & 2 with a crack in the same spot in the head. so that is was how i was getting water in the oil. after doing a lot of digging in attempts to find am affortable replacement motor i kept up coming up short. dad found me a motor that he knew was a marine motor but didnt know wanything else about it. look at it is looks to be the same as my 3.0 just much older i snaped some pictures of it posted them here (see thread "what did my dad buy me") and found out that was a 66-71 2.5l.
after doing a lot of research this is what i have found in compairson of the 2
bore stroke crank mains jernal crank rod jernals rod lgnth
2.5l 3.87 3.26 2.2298 - 2.299 1.998 - 2.000 5.7
3.0l 4.00 3.60 2.2983 - 2.2993 2.009 - 2.001 5.7
so now here is the plan.....going to take and use the 2.5 block and head only. use all of my internal componets from the 3.0 so i dont loose to much hp. so after looking at these numbers we know that the crank will fit and bolt in using standard bearings. then i use the rods off the 3.0 (with new bearings). find a set of pistons to fit accordingly (the 230, 250, 283 cid chevy motors all had the same bore). have th head (off the 2.5) cleaned up and checked out new selas in to make sure all is good to go. i could use either oil pan as well as valve cover. use the harmonic balancer off of the 3.0 (since it is on the crank) reuse the manifold risers carb altnator distrubator as well as the rest of the external componates.
i guess my first question about this ordeal is what about camshafts will the one ot of the 3.0 fit in the 2.5 block or are they even the same one? or can any one suggest a new grind for one?
does any one see any issues that i might run into wile working onthis project?any concerns here.
my main goal here is to get the boat back on the water as quickly and cost effective as possiable thanks for all the help in advance as i have learned a lot form this forum and sight
1 being i have mentioned some of this stuff on here before tings got confused
2 a differant thread i had started (about a head) started to go in this route so to get them on toppic i started a new on
a little background (or refresher) on the situtation. i bought my boat (1988 sunchaser 3.0 alpha 1 17' trihull deck style) in july of last year i was informed that it had a cracked block. i was hoping that it was just an external crack, but after "patching that up" rebuilding the carb and fresh oil in itwe took it to the lake. got it home only to find a milk shake looking stuff on the dip stick. changed oil again and and same isssue. had also noticed that it felt a little under powered when comming out of the hole noticed a litlf crank case ventaltation coming out of the vent tube on top of the valve cover. so i pilled the head to find the head gasket burned in 2 in between cylender 1 &2 an itwas busted between 2 & 3 upon looking thing over closely i found where the block was busted inbetween cylender # 1 & 2 with a crack in the same spot in the head. so that is was how i was getting water in the oil. after doing a lot of digging in attempts to find am affortable replacement motor i kept up coming up short. dad found me a motor that he knew was a marine motor but didnt know wanything else about it. look at it is looks to be the same as my 3.0 just much older i snaped some pictures of it posted them here (see thread "what did my dad buy me") and found out that was a 66-71 2.5l.
after doing a lot of research this is what i have found in compairson of the 2
bore stroke crank mains jernal crank rod jernals rod lgnth
2.5l 3.87 3.26 2.2298 - 2.299 1.998 - 2.000 5.7
3.0l 4.00 3.60 2.2983 - 2.2993 2.009 - 2.001 5.7
so now here is the plan.....going to take and use the 2.5 block and head only. use all of my internal componets from the 3.0 so i dont loose to much hp. so after looking at these numbers we know that the crank will fit and bolt in using standard bearings. then i use the rods off the 3.0 (with new bearings). find a set of pistons to fit accordingly (the 230, 250, 283 cid chevy motors all had the same bore). have th head (off the 2.5) cleaned up and checked out new selas in to make sure all is good to go. i could use either oil pan as well as valve cover. use the harmonic balancer off of the 3.0 (since it is on the crank) reuse the manifold risers carb altnator distrubator as well as the rest of the external componates.
i guess my first question about this ordeal is what about camshafts will the one ot of the 3.0 fit in the 2.5 block or are they even the same one? or can any one suggest a new grind for one?
does any one see any issues that i might run into wile working onthis project?any concerns here.
my main goal here is to get the boat back on the water as quickly and cost effective as possiable thanks for all the help in advance as i have learned a lot form this forum and sight
