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BBC B&M 174 Blower build Help

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BBC B&M 174 Blower build Help

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Old 02-13-2019, 01:23 PM
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Default BBC B&M 174 Blower build Help

I was about to comment on another thread that was somewhat related, there is a ton. I figured I'd start my own so I don't get of topic off the original posters question on another thread.

WHAT I HAVE:
2 bolt 454 block .060 over 289 casting
Speed Pro L2399F .095 Domed pistons
weiand dual plan intake with Holly DP 750
Hydraulic Flat Tappet lifters Unknown brand
Unknown Cam haven't removed yet. Damper puller is being barrowed getting that back tonight.
Head casting# 14096188 Rect port 2.19 Int 1.88 Exh 325cc Int Runner Volume 116cc chambers
Aluminum Glenwood manifolds with silent choice TRS drive setup
Looks to be stock crank and rods
Roller rockers with no markings.
This was removed from a boat I just purchased it did run upon removal, If I did the math correctly it should be 8.42:1-8.72:1 based on head gasket choice.
I just picked up a B&M174 Blower intake rec port for BBC and Demon carb don't know the size yet, for $600

WHAT I WOULD LIKE TO DO
make it a reliable 174 Blower setup 4.5-5 ish lbs of boost based on overall CR and effective CR when all said and done Rev limit at 5300RPM unless otherwise suggested.
Figure I can use the heads and rotating assembly. Do a valve train upgrade and figure out my exhaust and timing.

QUESTIONS
I will get the block checked out by a reputable shop. Not a question.
1.) Roller cam swap I was reading some older stuff on Crane cams 731 was a good option, no longer made along with long travel lifters. Any other good/ better options?
2.) Exhaust is not in the budget right now. Do I need to eliminate the silent choice and weld dumps on my risers for reversion issues?
3.) It had a billet MSD HEI vacuum distributer.I can block the vacuum advance off. What is a reliable way to control timing in this setup total being close to 30 due to the CR and possible starting issues with idle timing control? This is my most personally unknown factor into this build.
4.) Sounds silly. Should I change the plugs a few heat ranges going from N/A to something like this?

I would like to keep the cost down, as wouldn't we all. I do want this to be reliable though, so a littler extra here an there wont hurt for reliability. I will be going through the blower before installation. I'm sure I missed something.
Thanks.

Last edited by bhassett110; 02-14-2019 at 06:31 AM.
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Old 02-14-2019, 03:49 PM
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1. Crane 731/500 EFI cam. Look in the Swap Shop or post a request of Facebook. Someone will have a used one for sale, pretty much guaranteed.

2. I can't really answer about the exhaust without seeing it. I'd rather have better exhaust over the blower personally.

3. If you can disable the advance, lock it in at 30. If not, get another one that you can. That should get you close.

4. Definitely colder plugs... at least a couple of steps.

I would look to emulate the 525 SC being that the B&M 174 isn't really different from the Weiand 177 used on the 525. You'll need a big carb... 1000 CFM or so. A Crane 731 (500 EFI) hydraulic roller will work well. A 250 blower would be a better choice if you can find one.

Be careful! You need good fuel especially with the heat that the little blower will make once it really started spinning. You'll probably want to run without a thermostat to keep the block and heads cold. Also, an oil cooler and oil temp gauge are mandatory. If you're going through the motor and heads, upgrade the exhaust valves to Inconel.
.
Lots of reading to do in the forums around this. Lots!

Good luck with your build, and ask away! Lots of good knowledgeable people here on this very subject.
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Old 02-15-2019, 11:55 AM
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I will post an ad for a 731. I have been putting thought into the exhaust and I have decided I am going to build it off of the 525sc specs except for lower boost more comp.
and I will just wait to put the blower on it until I figure out a better exhaust setup, or at least find some stainless risers so I can extend the water discharge and eliminate the chance of water reversion with a cam like the 731. Inconel Exhaust valves are a must.

my next questions now would be.

Could I put a more mild cam in it than the 731 and run without reversion issues, then later down the road install exhaust and a different cam then?
Has anyone ran a small 174 or 177 with stock aluminum BBC manifolds and risers with success without reversion with a cam like the 731? My manifolds are Glenwood. Not much of a way to extend the stock water discharge on the stock risers I have I could heat them up weld them with extension pipes on the ends and cool off slowly, but that seems pretty risky and likely to crack not worth it. I should probably wait until I come across a different exhaust setup or stainless risers.

Last edited by bhassett110; 02-15-2019 at 12:01 PM. Reason: didn't read pervious posters comment in enough detail
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Old 02-15-2019, 01:23 PM
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TomZ is on the money with his advice. Id sort out the exhaust first as even EMI manifolds with long risers would do the trick. A smaller cam will only create more cylinder heat with an already hot 174 blower intake temps. The 731 is a great cam for NA that also responds well to boost as well, Ive been told.
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Old 02-21-2019, 07:01 AM
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Okay, so what would be my cheapest option that will work without a doubt when it comes to headers/manifolds/tailpipes, without having an issue with water reversion. I currently have stock replacement Glenwood aluminum manifolds with GIL captains choice. I would like to keep the Captains choice if possible, but if its going to cause issues I will not have a problem living without it. I will be going with a 731 cam ground on a 114 Lsa if I can find one. If not Teague marine makes a vary similar cam ground on a 112(not as favorable for reversion). I made a posting in the wanted section for a 731 with lifters. My setup is a TRS with merctrans, so I believe my tailpipes are longer than a regular bravo setup should help with reversion with the correct tailpipes. My tips exit above the water line.
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Old 02-21-2019, 08:27 AM
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I have done a bunch of research but am not as mechanical as the rest of the Dudes on this site. The key to keeping them alive seems to be forged pistons at the very least (forged everything if you have the $s), low compression, low boost, and very good gas. Too much timing, poof. Too much compression or boost, poof. Too much temperature, poof. Improper Air to fuel ratio, poof. Triple oil cooler capacity, get some sort of AFR gauge to ensure fuel is right across entire rpm range, best gas you can find and heads/exhaust to get the heat out.

Like you I have a pair of 177s with intakes and 1050 carbs but plan to put them on 8.5:1 454 Mags (forged internals), Gil exhausts with 4-foot pipes and late water insertion, and I am having wedges made for O2 sensors and AFR gauges. Got complicated fast - probably should just buy some solid old school 500HPs instead.....but blowers are so cool.

I jeep reading that some guys get away with non forged internals for years but frankly seems likel luck and with my beast being a heavy cruiser I dont think they would long. My 2 cents
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Old 02-21-2019, 09:21 AM
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Yeah, the more I've been searching this topic has really been beaten to death. I have forged pistons, don't plan on forged anything else 8.42-8.72 for CR based on head gasket.
I figure 30 degrees in by 2500 rpm
GIL manifolds with stainless risers or equivalent would like to keep captains call. (Still have to buy)
731 full roller setup (still have to buy)
cloyes double roller timing( Have)
4.5lbs of boost at 5200 with rev limit at 5300(Have blower)
Msd marine ign box(Still have to buy)
Msd coil and distributer (Have)
should be safe
This will be taken to St. Clair engine performance a friend owns the business. We will dyno and tune it properly with a 1050 dominator
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Old 02-21-2019, 12:33 PM
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Post #1 says 2 bolt mains. I would at a minimum have studs installed and have it aligned honed.
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Old 02-21-2019, 12:53 PM
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Originally Posted by 1BIGJIM View Post
Post #1 says 2 bolt mains. I would at a minimum have studs installed and have it aligned honed.
It is a 2 bolt main, but with it only being at 4-5lbs of boost at a max of 5300rpm I think the 2 bolt mains will be fine. Studs will be in order along with machine work. If I was going to spin it much higher with more boost 7+lbs I would definitely find a 4 bolt main block.
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Old 02-21-2019, 07:50 PM
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I built a 468 with 2399 pistons, 088 heads, crane 134561 cam, 525sc. It made [email protected] I have since upped the boost from 4.5lbs to 7.5lbs. It rips. 110hours on it. Rock solid motor.
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