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Is the Mercruiser 470 a flat tappet engine?

I believe that this engine was designed and put into production long before everyone was on board with roller cam followers.

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If you purchase Mercury 4 cycle oil 25w-40w then you should be fine as it is there oil........

The 470 uses a hydraulic lifter not a solid lifter.
 
Ya that was probalby a dontov 30-30 cam??? and if you set the clearence just a tad tighter it actaully would give a bit more lift if I remeber correctly.

something like .025 on the exhaust and .028 on the intake..........been awhile.............
 
Alot of the oils you buy now lack the ZDDP. There have been lengthy discussions about this on "discussion forum: breezeworks 470 talk". Also, there are a few aftermarket roller rockers kits you can get for the 470. (Scorpion roller rockers?) Don't hold me to that but you should be able to find this out on the site. I think one of the Rotella oils contains a higher level of ZDDP. If you decide to install roller rockers you also would have to find a valve cover spacer as there would not be enough clearance with the stock valve cover. There was also plenty of arguments concerning the issue of lifters. lol I believe after reading on, that the valve train is considered a solid lifter setup. The lifters do pump up with oil, but the pushrods have to be a specific length giving a minimum clearance at rocker and valve stem of I think .011 and a maximum of .021. It has to be set before pumping lifters up with oil. (The book says that you are supposed to take lifters apart if reusing them). More of a cushion for a better word. Been there and done it. Had to order custom length pushrods from a speed shop to attain proper length for clearances after installing reconditioned head. The old pushrods were too long from original head and couldn't be used. I think getting this right was one of the most challenging with respect to rebuilding a 470. Especially if you are doing it for the first time. lol I guess what I am trying to say is the valve train is non adjustable if running with stock equipment. kghost, I pushed some buttons when I mentioned about hydraulic lifters on the other site. lol No disrespect to you in any way but these guys will argue about that until the cows come home. lol I thought the same as you initially and was corrected pretty quickly. It's all on the other site in the archives if anyone is curious. I know how you guys just love these little engines. lol Just kidding! Anyway, that is all that I can think of at the moment about the 470 and respective valve train issues. Alot of guys have the roller rocker setups but not really sure how much of a pain in the ass it is to setup correctly. If I was going to go to all that trouble I think I would install an aluminum head along with all the goodies. Too much $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$! later, Tom
 
To the best of knowledge/memory and it has been a while since I had a 470 apart BUT, The lifter itself is a hydraulic lifter. It has a plunger and spring and an oil cavity beneath the cup. (simple description). A solid lifter is just that SOLID with no real oil cushion other than for lubrication purposes.

That being said the 470 is no different as many other engine/vavletrain designs with a fixed push rod lenth. Even Harley's have this. When one installs a bigger cam or as in your case milled the heads, one would simply use an adjustable pushrod. The push rod is a two piece design with a locking nut system.

Other manufactures such as I believe pontiac, buick obviously Ford as the 470 head is ford used fixed/non adjustable rocker arms.

hERE is some facts...........Just for info not for argument....lol





Hydraulic vs. Mechanical (Solid) Lifters

Both lifter types look the same from the outside, with both having pushrod seats held in by a retaining clip. In a hydraulic lifter the seat moves by means of a hydraulic valve and oil pressure within the lifter. The mechanical lifter does not have a valve and is solid.

The pushrod seat in a solid lifter sits upon an internal step inside the lifter body, preventing it from moving. The hydraulic lifter, on the other hand, has a pushrod seat that sits on top of a moveable hydraulic mechanism which acts like a tiny hydraulic pump. Below this mechanism are a valve and a spring to produce an upward force, moving the seat up against the pushrod when the lifter is on the base circle.

Solid cam designs require a running clearance or “valve lash”. Hydraulic cams are the exact opposite. In a standard hydraulic lifter the pushrod takes up all of the clearance and submerges into the lifter’s pushrod seat approximately .020"-.070". The distance that the pushrod submerges is known as the “pre-load”.

Setting Valve Lash With A Solid Lifter Camshaft

First, check the spec card that came with your cam for the correct valve lash specifications. All COMP Cams® valve lash settings are “hot” settings (set at normal engine operating temperature) but will work for initial start-up as well.

Turn the crankshaft in the direction of normal engine rotation until the exhaust pushrod of the cylinder you are adjusting begins to move upward, opening the valve. Adjust the INTAKE lash by tightening the intake rocker nut with the correct thickness feeler gauge inserted between the valve stem and the rocker tip. Tighten the rocker nut until there is a slight drag when moving the feeler gauge. Next, rotate the engine until the intake pushrod fully opens the valve and then goes half-way back down. Adjust the EXHAUST rocker nut (with correct feeler gauge) using the same procedure. Repeat for all cylinders.

After setting your valve lash with the engine cold, start it and follow the appropriate break-in procedures. Due to thermal expansion, your valve lash will now be tighter than it was when the engine was cold. Repeat the adjustment process to ensure that your valve lash matches that specified by your cam card at normal operating temperature.

Note: Check with COMP Cams® on valve lash settings if using aluminum heads or blocks.
Setting Hydraulic Lifter Pre-load (Adjustable Valve Train)

When installing a hydraulic cam, lifters or rocker arms, establishing the correct lifter pre-load improves both performance and engine life. Insufficient pre-load will create excessive valve train noise and wear. Excessive pre-load will cause rough idling and low manifold vacuum, and can even lead to severe engine damage. With an adjustable valve train, proceed as follows:

Install the pushrods and rocker arms. Be sure the pushrods are seated correctly in the lifter and rocker arm. Turn the engine over in the direction of rotation until the EXHAUST pushrod just begins to move upward, opening the valve. Now adjust the INTAKE rocker of that cylinder. Carefully tighten the nut on the intake rocker while spinning the pushrod with your fingertips. You will feel a slight resistance in the pushrod when you have taken up all of the clearance. This is “zero lash.” Turn the adjusting nut to the specified pre-load – typically 1/4-3/4 of a turn, but this will vary based on the lifter number.

Turn the engine in its rotation direction until the intake pushrod comes all the way up and almost all the way back down. Now set the EXHAUST rocker to “zero lash” and add the specified pre-load. Repeat this process for all remaining cylinders.

Setting Hydraulic Lifter Pre-load (Non-Adjustable Valve Train)

COMP Cams® recommends using an adjustable pushrod to check the pre-load. Typically, only one cylinder needs to be checked in this process. After applying lube, install the adjustable pushrods and assemble the valve train. Using the same procedure mentioned earlier, adjust the intake and exhaust valves to zero lash by changing the length of the adjustable pushrod for precise fitment. Order a pushrod that is .020"-.070" longer than the pushrod length at zero lash to ensure the proper pre-load.
 
Hy-Jack in progress...... keep your seats, and nobody move! :D

Getting completely side tracked here..................

Just an FYI..... the hydraulic portions of the cam follower are as follows.


139_0412_cam_5_z.jpg


The roller tip cam follower is basically the same as this flat tappet. The F/T is simply minus the roller contact to the cam lobe.
(of course the cam lobe profile is completely different also)


After looking at the image, click on this .gif file... pretty cool little dynamic demonstration.

http://www.youtube.com/watch?v=lorANZ1Tptw



An interesting tid bit..... when these hydraulic cam followers were first introduced, they were advertised as "Self Adjusting"..... and basically, that is what they are today.


BTW and FYI re; the mechanical followers (aka Solid Lifters)..... any change to the lash, only increases/decreases valve lift to the tune of the lash change.
IOW, there is no multiplying at the rocker tip/valve stem, as there is when a height change to cam lobe occurs.

****************************

When adjusting these statically, I'd suggest using the full stop procedure..... no short cuts, per 'se.
IOW, 4 cylinder engines require 4 stops @ 90* crankshaft separation......, 6 cylinder engines require 6 stops, and 8 cylinder engines require 8 full stops @ 90* crankshaft separation..... beginning with #1 TDC C/S, and right on down the firing order!
Do this, and we'll be on the base circle or "Heel" of the lobe.

I will never use the 2 or 3 stop procedure for any V-8!

.
 
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I totally agree with both of you guys and really appreciate the awesome info. My point was that when I posted that the lifters were hydraulic on the other site, I almost got attacked! lmao! Anyway, I went through all this stuff on my rebuild and actually found it to be quite a bit of a challenge being unfamiliar with the 470 engine type. Rick, I did adjust the valve train statically and went through all that you mentioned with the 4 cylinders and strictly by the Merc. manual. So far, so good. kghost, great information as always. thanks guys, Tom
 
So wrestling coach, you went ahead and bought the '84 Grady White against everyone's advice? Well I say good luck and I hope it works out for you. I've got an old boat too and have had lots of good times fixing it up. If you ask my wife she would tell you that she hates it. But she loves riding in it so it works out well. Come back to this forum for advice. There's lots of good people waiting to help.
 
holinwtr said:
So wrestling coach, you went ahead and bought the '84 Grady White against everyone's advice? Well I say good luck and I hope it works out for you. I've got an old boat too and have had lots of good times fixing it up. If you ask my wife she would tell you that she hates it. But she loves riding in it so it works out well. Come back to this forum for advice. There's lots of good people waiting to help.
Click to expand...

Yes I did. The previous owner had the boat for 20 years. He was very careful with maintenance and upkeep. It was always in fresh water (Lake Ontario), always on a trailer when not in use and stored inside when not in use. I can find my way around most engines new and old. If I get over my head I am near an excellant Mercruiser dealer on the St. Lawrence River. So everybody's input considered versus the history of the boat I decided this was for me.
 
1973 Browning Marine said:
..............
1.... My point was that when I posted that the lifters were hydraulic on the other site, I almost got attacked! lmao!

2.... Rick, I did adjust the valve train statically and went through all that you mentioned with the 4 cylinders and strictly by the Merc. manual. So far, so good.
Click to expand...
1... Tom, what/why were these guys giving you crap about hydraulic followers? What was it that they said?
Just curious!

2... glad that it went well.


FYI: these engines share a common seal location at/for the separation between the camshaft and the engine circulating pump impeller!
This seal is actually at the FWD end of the camshaft.
IOW, this special seal keeps oil on one side, E/G coolant on the other.
Point being; do not exceed the OEM Closed Cooling system pressure cap rating.
Keep her on the low side, and perhaps install a coolant recovery system.
 
I think they were basically arguing the point about the lifters being "solid" as I can recall. So, I basically went along with it just to keep the peace. lol I know they have oil in them so basically agree with you guys that they are hydraulic. Anyway, the valvetrain is a little tricky the first time around and the Merc. pushrods for the 470 are no longer available so I went to a speed shop and got some (custom lengthed non-ball end type). The guy told me they were better than stock. Probably not necessary for the 470, but don't think I had any other choice at the time in order to get the engine up and running.($50) I have been reading your posts about the 383 build for the last year or two and have to admit. That's an animal! lol I just might try and find the time for a project like this, of course with some assistance from you guys. (especially you Rick) You seem to know most of the do's and don'ts on this particular build. I also read that you can use a 400 block instead of doing as much machine work to the 350 deck. I read about one called a 434? What a savage! lol Maybe I can locate a 350 four bolt or better yet a 400 four bolt and maybe start this winter. Some of these engines have 12:1 compression so I am guessing that you are trying to lower compression a bit so it does not self destruct with the particular type piston you mentioned (say9:1) I guess the higher compression strokers are more for race cars and the like. I guess the correct marine cam would have to be installed also to make it work. I know I am way off with this post but have been thinking about it for a while so figured I would get the juices flowing! lol talk to you guys later, Tom
 
Ok I am the OP. I understand that these are not "solid lifters" and do pump up hydraulically. Now the oil. Lower ZDDP levels in our oils these days. Can I use a full synthetic like Mobil 1 15w-40 extended life and/or dinosaur oil like Shell Rotella 15w-40 diesel oil with higher ZDDP levels and a heavier additive package.
 
I won't tell you what oil to use but I personally run full synthetic 10w-30 (I think Castrol) I have read alot of positive posts about Mobil 1 products. Another guy won't run anything but a specific Rotella brand with the additional ZDDP (I forget the name off hand but it definitely was a Rotella product and definitely not 15w-40. That is more for diesel engines rather than gas. It is a specific type that I just can't remember at the moment. There are old posts in archives on breezeworks 470 talk discussion forum about this very subject. Or simply post with the same question and ask for stractor. best of luck, Tom
 
I run mobile 1 15-50 in my 1987 350 merc since 1995.
I run mobile 1 10-30 in my 1996 350 efi gmc 4wd since 1996
and i run mobile 1 20-50 in my 2004 harleydavidson since 2004.

That is what I use.

You can not go wrong using mercs oil 25-40 reg dino oil.

Anything else is up to you...
 
This should actually be a new thread.... but since the OP's question has been responded to, I'll continue with a hy-jack here!


1973 Browning Marine said:
...........
1.... I also read that you can use a 400 block instead of doing as much machine work to the 350 deck. I read about one called a 434? What a savage!

2.... Some of these engines have 12:1 compression so I am guessing that you are trying to lower compression a bit so it does not self destruct with the particular type piston you mentioned (say9:1)

3.... I guess the higher compression strokers are more for race cars and the like.

4.... I guess the correct marine cam would have to be installed also to make it work.
Click to expand...
Tom

1.... The 400 cu in casting incorporated Siamese cylinder walls... not a good choice for Marine. :mad:
This is why the 5.7L block is used (4.000" bore), and a Modified 400 cu in 3.375" (95.3 mm) stroke crankshaft.
This equals a 377 cu in SBC.
Increase the bore to 4.030" and it becomes the 383.

2.... Yikes! 12:1 would cause some pretty severe Detonation in a Marine Cruiser SBC engine.
Tom, a 12:1 piston would not ressemble any of the Q/E pistons that I have shown.
None of the LCQ (Low Compression quench), D-Dished or Reverse Dome pistons are high compression pistons to begin with.
As the C/R is decreased, the dish volume would increase, and visa-versa.

3.... Correct!

4.... Correct! Water reversion, due to incorrect profile and lobe separation, is the issue!
If you had dry exhaust, it would make little difference, other than the correct profile for the Marine Load application.



Any further questions.... it may be best to start a new thread. :)
 
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