Project 496 Blower Motor

[LynnsJet]

Jim W made the suggestion in another thread that I share my engine build. It sounded like a good idea to me so I will do the best I can to share the experience.
Please keep in mind that this is NOT the "Ultimate Engine Build". If you want to read one of those stories buy a magazine where they build an engine with an unlimited budget, sterile shop, professional engine builder, etc.
My intention is to salvage as many parts from my original motor as possible.
L J

[HammerDown]

Do we really need another thread for this?

[Jim W]

Do we really need another thread for this?
Yes Hammer, yes we do
Be good, Jim

[LynnsJet]

Please don't read this. I wouldn't want to insult your intelegence by having you read the words of a mortal man.
L J

[Jim W]

So L J,
here's where I am at.
I may have my unfired BBC, blower motor sold. It's more of a street motor really. B&M 420, 427 2 bolt main, iron heads, carbed.
I am now putting part's in it that exceed the base engine's build up. I started off at 7-800 Hp and now am over 900 Hp and in a boat, not a street rod. Going to alcohol.
Time to stop and regroup.
What I am thinking of building over the winter is.
496 tall deck with nice forged internals.11.5/1 cr., Alu. heads, AFR with a healthy (.700+) solid, roller lifter cam, on alcohol with a birdcatcher. To top it off, I would love to get a Whipple charger rather than the usual 8-71 or 10-71.
At Anna this spring, I was soooo impressed with Jacks alky jet. I know that was the way I wanted to go.
Be good, Jim

[LynnsJet]

My intention was to use as many parts from my old engine as practicle. It was a 402 BBC with oval port heads, small rods, press fit pistons and a B&M 420 blower with 2 Edelbrock carbs.
The old engine dropped a value due to Reversion. Water hit my exhaust valve and made it brittle. It broke and tore up my head, block piston, rods, etc.
I got a donor engine, a Gen VI 454 425 HO (4 bolt mains, rectangle port heads, etc with a spun bearing. Since I had to replace the crank anyway my machinist, Rob Mahler, suggested I build a 496 stroker as the cost would be the same. I was all for it. We figured it would make about 700 HP by running 6 to 7 psi boost, etc.
The block was reconditioned (line hone, decked & bored .060 over, brass freeze plugs, etc.). The heads were given a competition valve job and the Crane springs and retainers from my old heads were installed and the head was decked. I needed to remove the stock springs because they were for a roller cam which would have been too stiff for my flat tappet cam and lifters.
Rob got all of the parts for me, kind of like a kit, so that they would be compatible. He has a lot better chance of picking the right stuff than I would sitting down with a catalog and buying a bunch of stuff.
The crank is an Eagle cast 4.25 stroke and the rods are Eagle I beams both of which are good up to 700 HP. The crank looks real nice. It has the large radius on the bearing surfaces and the oil hole are are chanfered real nice. The rods look much nicer than the stock rods and they have nice ARP cap screws instead of nuts and bolts. The pistons are forged SRP flat tops (.007 clearance). I found out, after much research, that no manufacturer makes a dish top piston for my 496 combination. You can get a dish piston for a 454 but not his deal. I really wanted to have 8 to 1 compression ratio but the flat tops got me about 8.6 to 1 with my 118cc combustion chambers which isn't too bad. My effective compression ration with 6 or 7 pounds of boost should still be in the range where I can still run 93 octane gas. I run my blower about 16% under driven which gives me the 6 or 7 psi boost.
The rings are Mahle - standard tension, Performance Rings (file fit). I fitted them to .024 end gap for the top ring and .028 for the 2nd ring as prescribed in the instructions that came with them (blower motor on gas).
The bearings are Clevite 77. The mains have .025" clearance (using plastiage). ARP studs are used with the main caps.
The cam is from my old motor. It is a Doug Herbert blower flat tappet hydraulic cam. I decided to not use the roller cam and lifters that were in the engine. A roller blower cam was another $450 and I was running close on money. I was also concerned that the 425 HO cam wasn't designed for marine use and it probably had too much overlap for a blower setup.
The bolt pattern for the old (Mark IV) cam is not compatable with the bolt pattern on a Gen 6 timing gear which used a single row timing chain. To change it to a double row chain I had to replace the timing cover with a after market billet aluminum one to make room for the double row chain.
Installing the full floating pistons on the rods was a bitch. They want 2 spiral locks on each end of the wrist pin. My fingers were sore after that deal.
That's where I am now. Tomorrrow I install the pistons and go at it from there. I will let you know how things go from here.
L J

[miketsouth]

The bearings are Clevite 77. The mains have .025" clearance (using plastiage).
L J
hmmm...... :2purples:
Lots of work, Lynn. If you can make the 700hp you will be spinning an A around 6k...
i want more..tell me more....like what kind of valves are in the head now...like actual measurement of the pistons(skirt, pin and pin90deg) and cyl measurements...like what the side clearances on the rods and thrust on the crank come out to be...like which lifters you are going to use on the used cam...like what headgasket and thickness you will use...like what method you use to torque the heads...oil system modifications or tests...valvetrain geometry setup and tests...and a picture is worth a thousand words.
I think it is great that you would take the time to expand the engine build for people like me who dont have much engine experience, but only book reading.

[DelawareDave]

The mains have .025" clearance (using plastiage).
L J
I hope this is a typing error. :eek:

[HammerDown]

The bearings are Clevite 77. The mains have .025" clearance (using plastiage).
L J
Using some thick oil I guess.

[miketsouth]

:rollside: I figured it was to cool the pistons, to make up for the slightly higher compression ratio, and lube the cam better...but i would not go over .007 as there might be some knocking when the engine was not under a load, and at idle below 1500rpm he might brinell the bearings...an oil cooler would be manditory for this setup...50wt at 100F--120F would be about right. :p

[Jim W]

700 HP @ 6,000 RPM???
Why not swap out the cam to a solid lifter and run the thing up to 7-7,500 rpm?
The parts L J is using is easily good for that kind of rpm.
L J............Just throwing some idea's at ya
Why limit the RPM to 6,000+ with a HYD. cam at this power level?? Swap it out for a solid lifter.
The cam you had in the 402 is not going to be the correct cam for the 496. With the blower, ya, the blower will fill the cyls. but the cam is wrong. I am going to guess you are missing out on 50 to 100 HP.
You can lower compression with thicker head gasket's or, have the pistons milled down a bit. Again, at this power level, you should be paying attention to details and not be skimping anywhere on the build-up.
You are going to need to get a blower pulley to keep the boost up at 6-7 lbs. Going from a 402 to a 496, the blower will need to be spinning faster with the added inches. Personally, I would go up closer to 12-14 lbs. and run a mix of either race gas or av gas. For the little bit of use a boat gets, adding some good fuel is not really that expensive.
You are going to need an oil cooler.
Lastly, I really would dyno the thing. Around me, the shops charge $250 to set an engine up. Pretty cheap if you think about the HP. you could be missing.
If nothing else, on the dyno you could run the engine on 93 octane gas and change blower pulleys to up boost until you get into detonation problems. Then mix in some race/AV gas and see how much boost you can go up to with that set up.
This would give you a normal lake set up and then you could change over to your race set up.
7,500 rpm.--solid lifter cam--lower the comp. and run 12 lbs. boost--somewhere around 900 hp. as a guess.
Cam and lifters----$200
Mill pistons--------$200
blower pulleys 3??-$150
Dyno day---------$250
total--------------$800
Just my 02
Be good, Jim

[HammerDown]

The cam you had in the 402 is not going to be the correct cam for the 496...
Ditto...
Not to mention why not take full advantage of the (newer) block with a roller set-up it was designed for.

[Jim W]

Ditto...
Not to mention why not take full advantage of the (newer) block with a roller set-up it was designed for.
Hammer,
I was trying to keep him away from $500 Morrell roller lifters and then the cost of a roller cam------>$300
Be good, Jim

[DansBlown73Nordic]

Ditto...
Not to mention why not take full advantage of the (newer) block with a roller set-up it was designed for.
Hmmmmmmmm the guy who thought this thread was a bad idea is now posting his .02 cents..... :rolleyes:

[Jim W]

LOL
Now all we need is the guy building the engine!!!!!!!!
Be good, Jim

[HammerDown]

LOL
Now all we need is the guy building the engine!!!!!!!!
Be good, Jim
He's probably flippin through a Summit book, looking for the right roller cam and roller lifters.

[HammerDown]

Hmmmmmmmm the guy who thought this thread was a bad idea is now posting his .02 cents..... :rolleyes:
Off topic but...
Ya know what they say about opinions...and thanks for yours. :D

[DelawareDave]

Can you feel the love? :p

[DansBlown73Nordic]

Anytime..... :wink: :wink:

[Jim W]

In my opinion...........Dan owes me a set of pliers!!!!! :rolleyes:
Can you believe this weather??? Rain, wind and 54 degrees out?????
Be good, Jim

[HammerDown]

Updates...?
Hows that rotating assembly going?
Are we getting closer to the go button?

[LynnsJet]

This is a Jet Boat engine. The impellars in the pump are not efficient over about 6,000 RPM's. This motor is designed for 700 HP. Note the cast crank and I beam rods. I am sticking to plan. If I wanted to get caried away and build a 1,000 HP monster I sould have used a forged crank and H beam rods.
The cam is a blower cam. It doesnt know how many cubic inches I have. I may have to change blower pulleys but I won't know until I run it. I don't want 12 -14 psi because that would raise my effective compression ratio way up there and I don't want to use anything higher than 93 octane.
Thick head gaskets would decrease my quench. Having a .040 quench tends to reduce detonation. Living with the 8.6 to compression ratio will fit into my plan if I control my boost.
I really am sticking to my 700 HP plan.
Don't forget that just having the blower sit on top of this motor makes it the whole deal look neat and it makes a nice sound that I can listen to as I motor along. Plus it's fun just watching the belt go around when you are cuising.
L J

[LynnsJet]

I have .006 crank end play. My rod bearing clearance is .002 and my side clearance on the rods is .012. I used a FelPro head gasket (for the 4.310 bore) that is of nominal thickness to maintain my .040 quench.
I kept the stock valves that came in this crate motor - 425 HO.
I mentioned that putting the spiral locks in the pistons was a bit of a bitch. What would be more of a bitch is if I put the pistons on the rods backwards and I had to remove the locks to turn them around. It sounds like a simple thing to put the pistons on but I can assure you that it is equally easy to put them on backwards and have to redo it or end up with a valve hitting the piston. I was very careful diring this stage of the preparation.
I used Clevite 77 bearing which are a very popular bearing. I was lucky that a friend told me about the upper and lower markings on the bearings for a bbc. I was used to small fords and where there is no difference between the uppers and lowers. The reason for having a difference in the two halves is that they cut a belvel on the one side of the bearing to allow for clearance with the radius of the journal. If you reverse the halves you end up with no clearance between your rods.
I mentioned my ring clearance earlier (.024 for the top ring and .028 for the second ring). Achiving this clearance was an interesting process. First of all the tool that I used to grind the ends of the rings was pretty new so it took an aggresive cut with each revolution and it did not take a lot of effort to get the required clearances. After the grinding I followed the recommendation of the ring manufacturer and I touch the sharp edges of the ring ends with a stone to remove the burrs. I tried to get away with just removing the burr from the wear side of the rings at first but I found that there was a burr on the top and the botton of the ring that prevented the ring from moving freely in the pistons ring land. A detail tha could easily have been over looked.
After I installed the pistons I found top dead center of piston #1 and marked my new timing cover to correspond with the hash mark on my vibration damper. I wanted to be sure I had a good reference point to start with when I was ready to check my cam timing and set my ignition timing.
Everyone says to use a ring expander to install the rings on the pistons. I bought a new one for this project and paid a wopping $6.00 for it. It made the job easy and I didn't scrape up the pistons at all. Another case where you need to follow directions and do it the right way.
The cap screws in my Eagle rods were made by ARP. I lubed the threads and under the head with ARP assembly lube. Note that the torque required to get the proper tension is not the same with oiled threads and those that have assembly lube on them. The assembly lube is very slick so they require less torque.
Most engine books make mention of cleaning the threads in the block after it is machined. Since bbc's require the use of a sealant on all of the head bolts because they go into the water jacket I wasn't surprised when I ran the tap in the holes I found that all of the threads in the block were junked up with the old sealant.
The proper sealant to use is teflon based. They say not to use RTV on the threads so I stuck with ARP thread sealant. I put a little assembly lube between the head of the bolts and the washers. Stock head bolts do not use washers. Since I had a set of ARP head bolts & washers in my 402 and I knew how old they were, I felt confident that they were in good condition so I used them again in this motor. If I didn't have them I probably would have gone to ARP studs for the heads. When I torqued the heads (to 70 ft lbs with ARP assembly lube) I tighened then in a X pattern starting from the center and I worked my way outward and I worked my way up to the prescribed tork in 10 lb increments.
At this time I took the afternoon off and went to a friends house to eat Maryland crabs and drink beer.
L J

[HammerDown]

I used Clevite 77 bearing which are a very popular bearing. I was lucky that a friend told me about the upper and lower markings on the bearings for a bbc. I was used to small fords and where there is no difference between the uppers and lowers. The reason for having a difference in the two halves is that they cut a belvel on the one side of the bearing to allow for clearance with the radius of the journal. If you reverse the halves you end up with no clearance between your rods.
At this time I took the afternoon off and went to a friends house to eat Maryland crabs and drink beer.
L J
Any Clevite bearing I've seen was marked clearly "upper/lower"...please tell me you didn't clamp them down installed the wrong position!
Keep up the good work and keep us posted.
Crabs and beer...can't get any better than that...now I want Crabs-in-beer :rollside:
Off to The Tap Room later!

[Jim W]

Sorry L J,
I completly missed the cast crank......
I did see the I beam rods.
Are you sure about the 6,000rpm impeller deal. Dont the high HP jet boats go over 6,000 rpm?? V-drive guy here and a newbie at that.
If you didn't have the blower, I think you would be very unhappy with the cam.
How long untill you get it fired up?
Be good, Jim

[miketsouth]

I have .006 crank end play. My rod bearing clearance is .002 and my side clearance on the rods is .012. I used a FelPro head gasket (for the 4.310 bore) that is of nominal thickness to maintain my .040 quench.
L J
this sounds right to me. If quench works, it appears you will need it.
I kept the stock valves that came in this crate motor - 425 HO.
L J
this is not a place to scrimp IMHO. Not the exhaust valves anyway. I dont know much about valves but i have EV8 stainless undercut ones
After I installed the pistons I found top dead center of piston #1 and marked my new timing cover to correspond with the hash mark on my vibration damper. I wanted to be sure I had a good reference point to start with when I was ready to check my cam timing and set my ignition timing.
L J
a most important step IMHO.
Most engine books make mention of cleaning the threads in the block after it is machined. Since bbc's require the use of a sealant on all of the head bolts because they go into the water jacket I wasn't surprised when I ran the tap in the holes I found that all of the threads in the block were junked up with the old sealant.
The proper sealant to use is teflon based. They say not to use RTV on the threads so I stuck with ARP thread sealant. I put a little assembly lube between the head of the bolts and the washers. Stock head bolts do not use washers. Since I had a set of ARP head bolts & washers in my 402 and I knew how old they were, I felt confident that they were in good condition so I used them again in this motor. If I didn't have them I probably would have gone to ARP studs for the heads. When I torqued the heads (to 70 ft lbs with ARP assembly lube) I tighened then in a X pattern starting from the center and I worked my way outward and I worked my way up to the prescribed tork in 10 lb increments.
L J
My ARP head bolts came with the same command. I did not listen. I chased the threads, tested each thread and bolt. I used Hylomar as a sealer and the provided assembly lube. I did the recommended torque and sequence, while measuring the crush at the ends of the heads where i could. After that i removed every bolt, one at a time and marked and retorqued them. Got somewhere near 1/8 to 1/4 turn. Did it make a difference? Probably not.
At this time I took the afternoon off and went to a friends house to eat Maryland crabs and drink beer.
L J
The best part of any build. Too bad i could not get them in the winter when i was working on mine. Good information Lynn...
i never used a ring expander. I got to check that out.

[LynnsJet]

I ordered pushrods for my engine. Not wanting to take anything for granted I installed two adjustable pushrods for #1 cylinder that were adjusted to the length of the suppplied pushrods. I then rotated the engine and observed the movement of the roller on my adjustable rocker arms, also salvaged from my 402, and I found that the pattern of movement on the tip of the valve was not correct.
I then started adjusting the pushrods, one at a time and after some trial and error I got a good pattern of movement. A good pattern is one where the roller tip of the rocker arm moves from one side of the center of the valve tip to an equal distance on the other side of center of the valve tip.
After I found what I thought was the correct pushrod length I checked it with an alternate alternate method and that is to rotate the engine to the mid point of the travel of the valve and examine where on the valve the roller was. At mid point of valve travel it should be in the center of the valve, which it was.
I removed the two adjustable pushrods and measured them. I looked at the Summit catalog and the Jegs catalog and I could not find a matching length of pushrod. Somewhat perplexed I started doing some research and finally found that the measure ments I recorded corresponded with those listed for a Gen V 454 engine. Since I have a Gen VI that I installed a flat tappet cam into, it made sense that my measurements were the same as the Gen V which is very similar to a Gen VI except the Gen VI normally has a roller cam and lifters. The pushrods that came with my donor motor are about 1" too short because the roller lifter that were used in the Gen VI was much taller than a flat tappet lifter.
I still have to locate the correct lifters but at least I know that I will have the correct rocker arm geometry when I get the valve train together.
It would have been very easy to put the engine together with the wrong pushrods that would have worn out quicker than normal and possibly failed. It proves that you can't take anything for granted.
L J

[LynnsJet]

I ordered a set from Summit today. The only problem is that the price was double what you would pay for the stardard size pushrods listed in the catalog. I should have them by Thursday.
The motor is in the boat and almost everything is buttoned up except for the pushrods and the exhaust.
Thanks for the help.
L J

[miketsouth]

A good pattern is one where the roller tip of the rocker arm moves from one side of the center of the valve tip to an equal distance on the other side of center of the valve tip.
After I found what I thought was the correct pushrod length I checked it with an alternate alternate method and that is to rotate the engine to the mid point of the travel of the valve and examine where on the valve the roller was. At mid point of valve travel it should be in the center of the valve, which it was.
L J
This is what all the cam manufactures websites say, and i suppose it makes sense in that the valve rock would be equalized and less valve stem/guide wear.
another method used, and should be checked, is the rocker position angle in relation to the valve stem at mid lift.
Steelcomp explains here:
http://***boat.com/forums/showthread.php?t=103410
To me, the second way makes more sense. I was lucky in that both conditions were met well enough for me, and i did not have to buy new pushrods. Well, actually i did buy some .10 longer ones on recommemdation of the guy who sold me the heads...they would have worked, but when i rotated them the balls were all over the place wierded out the rockers, as well as not being very good at either angle or roller position. They didnt even make good trash.
Roller position. I dont know about a BBC but the SBC took some managing of the guide plates to get a position on the valve i liked.
Oh yeah, i pumped up my lifters with a thing i made and a drill to make the measurements.
Looks like you gettin it done Lynn....How was the crabs....My wife making a crab soup right now from the ones left over from Saturdays party.

[fakethis]

Put a bbc in the boat mouseboy ! :idea:

[LynnsJet]

The crabs were really good. Heavy and spicy. The beer was ice cold.
What a great way to take a break from my motor (engine).
All I need now is the pushrods (Thursday, I hope) and get them in and the headers on and set the timing and I am hot to trot.
By the way did I mention that Gen VI's are externally balanced. It has a 8" damper and I used a steel flywheel on it this time. The reason being, a flexplate with a weight on it and no torque converter to support it, may have developed problems later on. I know this flywheel isn't going to crack and fall off any time soon. I think I will have enough power to spin that heavy thing. What do yo think?
L J

[HammerDown]

Why use up energy trying to spin up a flywheel?

[miketsouth]

Limited Knowledge of flywheels in jetboats:
unlike a car a flywheel in a jetboat is not gonna cut your engine acceleration time enough to matter and it will even out the natural pulsations of the engine especially at idle, maybe less pump rattle. They are heavy, and will cut mph acceleration as any weight will. It must be rated for the rpm you intend to turn.
The flexplate in a jetboat is gonna outlast all the rest of it, probably. Tooth failure from poor starter alignment being the exception. Piston failure, valve failure, bearing failure block failure and any other failure is likely to come first, unless it is a SMALLBLOCK FAKETHISthe way they are run. It also should be heavy duty. The flexplate, the POS it is, may travel funny without its torque converter and can be bent to travel correctly.... :rolleyes:
when changing from a flexplate to a flywheel driveshaft alignment and position is to be considered as well as insuring the proper size bolts. the extra thickness could push the driveshaft too far into the pump.
Cold Beer and Maryland Crabs...better get em while you can. I find later in the summer the better they are.

[LynnsJet]

I said that "The reason being, a flexplate with a weight on it and no torque converter to support it, may have developed problems later on".
A flexplate on an externally balanced engine has a weight on one side of it rotatin around putting stresses on it. Since a flexplate is made to be bolted to and supported by the torque converter in a car, the thought is that it could develope cracks as time went on. It was Rob Mahler (machinest) that recommended it. I followed most of his recomendations becaise I trusted him and I felt that he has the experience to help me build a reliable piece.
L J

[LynnsJet]

The longer bolts certaily were a challenge. Finding 7/16 x 20 x 2" socket head screws took a little work because it is not a popular size. For $2.61 each at A&A Bolt in Baltimore I was in business.
I tried to get 12 point bolts but they were not available at all.
It is together now. When I bolted everything up to the pump I had just enough room to get everything in there.
All I need now is for my pushrods to arrive today (as promised) and I should be able to fire this thing up tonight.
L J

[LynnsJet]

The correct length pushrods arrived as promised. I installed them along with the rocker arms and adjusted the valves annd checked to make sure that their length was correct using the procedure described earlier.
The procedure I used for adjusting the valves was the one prescribed by Mercury. As each valve was brought into position I adjusted the rocker arms to remove all the clearance and then tightened the hex nut 3/4 of a turn and tightened the set screws. Then I then torqued the hex nut to 30 lbs which is a little different than the procedure I had used before but one that Mercury prescribed because it is so difficult to adjust the valves "hot" in most boats because of the tight engine bays and header configurations.
Even though I had oiled the engine before I installed the intake I did it again. I used a drill to spin the oil pump to make sure I had oil coming up to each rocker arm.
I installed the distributor and tried to install the valve covers only to find out that I had interference between the Chrome steel Edelbrock valve coves that I had used on my Mark IV engine and the #2 & #7 intake rocker arms. I gently filed away some material from the corner of the aluminum rocker arms to gain some clearance. I reinstalled the valve covers with no other problems.
My first attempt to start the new engine (in the garage with no water in it)was a little troublesome but after a twist or two of the distributor it started. I quickly checked the timing and quickly shut it off. I was pleased that the engine idled properly and had no obvious oil leaks.
It was, as is always the case, great to hear your new engine come to life.
I will take it to the water today to give it a proper tune up and break in.
L J

[HammerDown]

It was, as is always the case, great to hear your new engine come to life.
I will take it to the water today to give it a proper tune up and break in.
L J
Tick-Tick-Tick...were waiting...? :cool:

[LynnsJet]

I took it to the river and it ran good. I kept it between 2500 - 3000 RPM's to give the cam time to break in. I noticed that the engine had a lot more vibration than my old engine and then I lost my alternator belt so we brought it home.
I spoke to 737 JetMech about it and he said he had the same problem once with one of his engine and it was the flywheel position on the crankshaft. I took it apart and sure enough the flywheel was 180* out.
It is all fixed now so we will give it another try tomorrow afternoon.
L J

[LynnsJet]

The alternator belt is fixed and rotating the flywheel fixed the vibration. Now I need to fix that darn fuel pressure regulator. It is junk as I have 13 psi fuel pressure no matter what I do to it. I tried cleaning it and that didn't help. I guess I have to find a new.
This deal gets better every day. It won't be long until I have it purring like a kittten.
L J

[Wet Dream]

when changing from a flexplate to a flywheel driveshaft alignment and position is to be considered as well as insuring the proper size bolts. the extra thickness could push the driveshaft too far into the pump.
Or, push the crank into the engine. Thrust bearings don't like that.

[Wet Dream]

Lynn, I have a Mallory Fuel Pressure Regulator, new, in the box, will sell, but I'm not sure if its the kind you're looking for.

[LynnsJet]

I bought an Aeromotive #13205 today and it mounted real nice in the same place that my Edelbeock regulator was. The nice thing about it is the fittings are pretty close to the same location so I won't have to change any hoses.
Thanks anyway,
L J

[HammerDown]

Heck I'm sorry there Lynn...but did ya blow out the lower-end on the engine?