improvments to 1970 1150

[johnnyrudeinator]

okay this will be kinda long...maybe should split it up. I have read that and been told the weak spots on the inlines are the cooling and fuel systems. This winter I'm going to rebuild carbs and fuel pump. will it hurt to go up to a larger diameter fuel line?? I have the two diaphram fuel pump set up...what about changing to the newer self contained pump?? which is better?? Anyone ever use a small carter or holley electric pump?? regulated that might be a good deal and give you a stead psi. Just a thought. What about the carbs?? just get a gasket rebuild or do I need to get new jets?? I will do the floats and needles. Also going to rebuild the water pump...lower piece all the way. I bought a new lower half off ebay off of a 75 and I forgot to check what the one on my new lower unit is....will they all work if you have the new base?? Can I just find the top and gasket impellor set that will go with my new base and it work?? she pees okay...but I would like to improve it..I know doing the pump will but can you do anything else to improve flow. I'll quit this one here and start another one. Thanks Alot for any imput!

 

[Scaaty]

Re: improvments to 1970 1150

okay this will be kinda long...maybe should split it up. I have read that and been told the weak spots on the inlines are the cooling..
kinda, but its a issue running full bore..take it easy on her, or dig into the block for a full upgrade
and fuel systems.
none that I know of if new carb kits, gaskets, diaphrams, 5/16ths new hose, etc
This winter I'm going to rebuild carbs and fuel pump. will it hurt to go up to a larger diameter fuel line??
5/16ths
I have the two diaphram fuel pump set up...what about changing to the newer self contained pump?? which is better?? Anyone ever use a small carter or holley electric pump?? regulated that might be a good deal and give you a stead psi. Just a thought.
quit thinking
What about the carbs?? just get a gasket rebuild or do I need to get new jets??
.080 fine..maybe .078 if ya be in the Rockies
I will do the floats and needles. Also going to rebuild the water pump...lower piece all the way. I bought a new lower half off ebay off of a 75
lower half of what?
and I forgot to check what the one on my new lower unit is....will they all work if you have the new base?? Can I just find the top and gasket impellor set that will go with my new base and it work?? she pees okay...but I would like to improve it
just get a new impeller kit..most all lowers that yearish all the same
..I know doing the pump will but can you do anything else to improve flow.
just rebuild it right
I'll quit this one here and start another one. Thanks Alot for any imput!

Nope, stick with this post...ya start another, I for one will breeze off..this forum gets confusing enough sometimes...just hang in there with this...some real wizards will add more

 

[johnnyrudeinator]

Re: improvments to 1970 1150

thanks alot...I really enjoy making improvments and doing things to old whatever. I just got done rebuilding a 1970 chevy c10. That was ALOT of fun. the lower half I was talking about is the lower half of the water pump....I'm going to replace the whole thing....sorry for the wrong use of words...the lower and upper housing, seals, gaskets, and new impellor. I love the sound of the motor...doesn't sound like the others on the lake...and REALLY sounds better than the four strokes and e-tecs. I have cummins with a straight exhaust and have had MANY V-8's with flowmasters or glasspacks...love sound. Thanks again for the reply.

 

[OldMercsRule]

Re: improvments to 1970 1150

I would stick with the 5/16 fuel line, which works great. Stick with the twin fuel pumps too. If ya search the threads here I gave the parts numbers this summer for the brass fittings on the silver blocks (like yers), to replace the wierd factory compression fittings that are prone to leak. Leave them alone if they don't leak. Scaaty luvs to tear things apart whether they need it or not. My philosophy: IF IT AIN'T BROKE DON'T FIX IT.

The fuel n' cooling systems are weak but if ya keep yer eye on 'em ya can run these motors fer forty years at least. Many of me "virgins" are that vintage and run fantastic!! JR

 

[emckelvy]

Re: improvments to 1970 1150

1970 115 Stack carries .066" main jets at sea level and ain't gonna run too well with .078" or .080".

Unless of course you want to split the crankcase and turn it into a 1350!!!!!

I'd recommend rebuilding the fuel system as per previous posts; in addition to replacing the carbs' needle/seat assy's, do the floats too. Set the float level IAW the book (if you don't have a book, hint, hint!).

Rebuild the water pump including new pump plate/gaskets, impeller, key, pump "cup" (insert), and pump grommet. You can get a good deal on Sierra replacement parts here: www.boatfix.com BTW they do have different grades of "pump repair kits" including one with a new upper water pump body, or one with both upper and lower halves, if that's what you're looking for.

Do the Clams Canino "Timing and Sync": http://forums.iboats.com/showthread.php?t=168855

Use midrange or premium unleaded fuel (unless all that's available is gasohol, then use regular only).

Prop for WOT around 5500 rpm (if you don't have a tach you need one!). This propping will give you the best performance when you're cruising at reduced throttle. Overpropping is death on these motors, they like to spin up!

Note that if you're using a 75 HP 4-cyl lower unit, the gear ratio is different. Your 1150 probably came with 1.78:1 gears whereas the 75 HP has 2.3:1 gears. It'll definitely affect your prop selection.

There's a mod to move the telltale outlet from the side of the exhaust manifold to the top of the block (other option, out the block water jacket cover). This mod ensures the block is positively vented and prevents 'steam pockets' from forming which might result in "hot spots". All you'll need is a 1/8"-NPT tap and tap drill. My buddy Thom in Shelton has perfected this mod and I've attached a couple of pics to illustrate.

One last thought, the later ('79 or so) Inline Six distributors had a modified "chopper disk" to help reduce preignition/detonation in #3 cyl. You might consider rebuilding your distributor this winter with new bearings, new snap ring, and the later-style "chopper". The snap ring is probably rusted and ready to self-destruct the Very Expen$$$ive trigger assy, so it's good preventive maint.

Anyway, HTH & enjoy your Tower of Power........ed

 

[Scaaty]

Re: improvments to 1970 1150

1970 115 Stack carries .066" main jets at sea level and ain't gonna run too well with .078" or .080".

ed

Wow, didn't think they were that small on the 115..thanks for that info ED...

 

[Scaaty]

Re: improvments to 1970 1150

I really enjoy making improvments and doing things to old whatever

Its a DISEASE.....I got it bad too...
"I love the sound of the motor.."
Yeah man! Still can't make up my mind of my 135 Merc TOP winding out, or one of my Harleys just loping in the shop at idle...plus they all look good JUST SITTING THERE!

 

[OldMercsRule]

Re: improvments to 1970 1150

The 45 degree brass barb in Ed's picture may work too, (but behind the starter on the top carb of those old girls the turn is a full 90 degrees).

I found a 90 degree 5/16 brass barb that will replace the factory fitting that leaks on all but one of me Silver Blocks. Ya can use them where ever the old crimpon compression fittings are, (which are usually a 90 degree turn). Most of mine leaked.

The 45 may work, but ya can get the 90 real easy.

Do you work on these girls, (other then yer own), anymore: Ed?

My $.02, JR

 

[Scaaty]

Re: improvments to 1970 1150

. My buddy Thom in Shelton has perfected this mod and I've attached a couple of pics to illustrate.........ed

Hmmm, I thought the corner of the garage/shop in the background looked familer in the first photo!

 

[Scaaty]

Re: improvments to 1970 1150

The 45 degree brass barb in Ed's picture may work too, (but behind the starter on the top carb of those old girls the turn is a full 90 degrees). JR

Jim, its the fitting for moving the telltale up the rear water jacket, not the carb...

 

[OldMercsRule]

Re: improvments to 1970 1150

Jim, its the fitting for moving the telltale up the rear water jacket, not the carb...

OH OK, thought it looked like the one you sent me. Me = Bad, or maybe it's the one functional brain cell was nappin'. JR

 

[emckelvy]

Re: improvments to 1970 1150

Do you work on these girls, (other then yer own), anymore: Ed?

JR

I still do a little but not as much as I used to. Plenty of my own "projects" sitting the garage that I should be working on but ain't!

Mr. T has been a lot busier than I have these past few years! After I retire (less than 4 yrs!) I'll have more time to play and probably take on more jobs.

 

[Scaaty]

Re: improvments to 1970 1150

I

Mr. T.

Guess he has done a good "harvest" over the summer...last yak said I gotta stop over...
Does have a pretty ratty Flat Bottom, but just really needs a bit TLC. Came with a TOP 150, thats what he shot the arrow at...Good People...(and way too much stuff..wait until ya both quit working, and gets some crazy idea's. ...hope I'm around to sit there and watch you two wizards! Be well...