Thread: what to do with my 350 mercruiser...

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Opinions are very welcome on this one. I recently bought a 350 mercruiser engine off a guy at work (standard rotation) 260hp and a niiice even power curve (courtesy of the people at mercruiser who hooked me up with the info) and tore all the boat parts off of it...got it looking like a real automotive engine...so i tore it down to see if it really was the advertised low hour engine i bought. (talk about a clean bottom end) so i flipped it over and took the heads off to look at the cylinder walls just to make sure i liked what i saw...boy there was a nasty looking pit on cylinder 6, it caught my thumbnail quite nice....i was heartbroken...so now i have a prime candidate for a good boring out with money i dont have....so my question is should i save the 350 for later and just run my '68 307 that came in my 1968 chevy truck or should i just run it and carry some extra oil on me. i forgot to mention that i really want a cruiser...nothing special..no heavy duty stuff...just cruiser. i have a 3.54 rear and i bought a really nice rebuilt 1980's t5 off of ebay rated for 330hp (i cracked it open to make sure) top notch tranny. a stock 68 307 with the 5 speed does have the cool factor...but everyone really pushes the 350...i really wouldnt notice that much of a difference with my driving...the tranny can handle that mild 350 but i would always be wary of pushing it. like i said im a laid back guy and just want a cool cruiser. the 307 is amazingly clean for being from that era...i have no qualms with it besides its such an oddball.

btw...i bought an 87 stepside truck bed....looks amazing...who would have thought that the lines match....easy install too just weld up some brackets to level the bed. highly recommended

i am doing a 350 gm roller engine rigth now and it will have a boat cam in it. i have use the boat cams in big blocks to they work good. on the nick if just a pit and its not at the top of the bore then ball hone it and run it or if to bad bore one hole out and sleeve it back to stock and use you old pistons i would not do that. but can be done .money to do this would be a bit less than all new pistons . if it will be just a cruiser cast piston s are not that much money and bore it this would not add more than 300 to the build

Hey Pat, I've got that '99 Vortec that I am going to rebuild and use in the el cheapo T I am putting together. It too is a roller cam marine engine. So you feel that the marine cam profile is ok for the street in a mild application? That's good news, as I thought it might be too mild, kind of truck grind-ish. This will same me some bucks if so.

Thanks, Don

the pit is an inch down from the top of the block
its a pretty nasty little pit

the 307 is as clean as a virgin in church...straight little engine

well the rings may roll over it i have seen some stuff that you would think it would not work at all and it did. on the marine cams yes i think it will work fine on a cheap build .you may buy some thing that will sound more ratty but not work much better .they are made to pull hard and idle it will be fine.

Originally Posted by pat mccarthy

well the rings may roll over it i have seen some stuff that you would think it would not work at all and it did. on the marine cams yes i think it will work fine on a cheap build .you may buy some thing that will sound more ratty but not work much better .they are made to pull hard and idle it will be fine.

Pat: If I wanted ratty, what is the next step up? I see cams on ebay all the time that are take out Z24's or some similar number. Are these a direct drop in? I haven't played with a Chevy for a while, so this stuff is new to me.

Don

PS: I would prefer ratty to one that sounds like a boat.

ORrrrrrrrr I have a brand new 99 Vortec truck cam that I took
out of my short block when it was born.....it is brand new if anyone needs it.
Used the lifters in the engine, so I dont have spares.

Dont have the specs handy but a net search should turn it up.

Mike in Tucson

well i have use them and with headers they sound good you can not go much more than 480 on the lift with the stock springs look at elgin #e1135 480/480 lift 230/230 on 108 $150this one will rock . the zz3 is 474 and ex510 208and 221 @050 on 112 .smaller that the elgin i have nothing on the boat cam .

Thanks. I think I'll get it running on the boat cam and see what it sounds and runs like. If it is too tame, I can always switch it out later.

Appreciate the help.

BTW, hope I didn't hijack this thread. Really didn't want to do that.


Don

its straight, im sure there are a few people who need some info on those boat engines. the grind on the boat cam is kinda truck-ish, very flat curve throughout right from the start from the info i got through mercruiser. not peaky and very evened out power. seems to have nice pull, very tough. and it wasnt afraid to rev from what i remember....anyway, i decided to put the 350 on the shelf until i can do a proper rebuild on it bc its just to good to let go or thrash it until it dies (i dont run across too many affordable 350s here), that just might be the engineer in me talking. so, im gonna hook up the 307 (just to be the oddball guy here) with the 350's intake/carb combo (I have a crazy as hell buddy who wants me to put that 307 crank in the 350 to make a revving 327, told him i would do it if he funded it...he shut up right there, darn)
(the combo should fit from what i measured) and i need rework the carb to maximize the 307's flow. anyway...as we all know, the silver lining is most of the parts (and by parts i mean external accessories and maybe those roller tips and headers i bought for the 307) i put into that 307 i can reuse on the mild 350 that is gonna come to life in the future. i really just weighed both my candidates and went for the best one based on my needs...no hard feelings for the "hi-jack" Itoldyouso

What you say about the availability of engines in the South is true. We moved to Winston-Salem NC for a year, and the first thing I noticed it that there were very few used engines to be found, especially at a good price.

After awhile I figured out one possible reason. Your cars don't rust out, like I was used to in the North, so you tend to keep them on the road a lot longer. Up North the bodies and frames would fall apart but the engines were still in good shape, so we had lots of cheaper engines to pick from. When I lived in Pennsylvania I owned a lot of cars that wouldn't pass inspection due to rusted out frames, but the engines ran like a clock.

Regarding the truck-ish grind of the marine engine, I think that is correct also. A few years ago I rebuilt an S 10 4.3 to put in my one boat, and left the truck cam in it. The profile worked out perfect, and the boat tops out right at 4600, where it was supposed to.


Don

yes they make Tq and do not need much CR i would say great for a mild street cam a lot of the gm roller cams are made in bay city

I appreciate the responses especially pat...helped me realize it probably wasnt a good idea to run the 350 until it was propererly straightened out....bc it was darn hard to come across the 350 in the first place down here, and i dont want to thrash it til it dies. im all about preserving.