My rapido longblock (pics)

[MikDee]

Re: My rapido longblock (pics)

I appreciate your OPINION there, mikdee, but unfortunately that is all it is, there is no practical experience or real thought behind it. Book smart is easy, I can read about things as well as you can, but I also have been building small block chevy's for appr 22 yrs now and I can tell you what works short term (your ideas) and what works long term in the real world (the actual facts). Unless you've built a motor and watched it live out to 100,000 miles trouble free or 1500 hours trouble free, you don't REALLY know what you are talking about. Just MY opinion.
--
Stan

Well I've been wrenching for 44yrs, and most of my experience didn't only come out of a book, it was hands on, I'd call that practical experience! and I've built a few more different engines then Chevy's, so it looks like you need22more yrs to catch up to me.

And no, my 327 had a (newly designed) high lift hydraulic cam from the factory, till the cam snapped, and I put in a solid lifter "Duntov 2" cam, I'd like to see you adjust that with a feeler gauge statically.

 

[MikDee]

Re: My rapido longblock (pics)

You don't think a boat bouncing off of waves is splashing oil all over the pan and up into the crank.

Makes sense now, but just curious, is this standard equipment with marine motors, I never had one on my 250cuin/165hp straight six Mercruiser?

 

[John_S]

Re: My rapido longblock (pics)

"is this standard equipment with marine motors"


Yes, on SBCs anyway.

 

[MikDee]

Re: My rapido longblock (pics)

"I had a 62' Impala SS 327/300hp, and it would regularly rev to 7,000 rpm with no lifter float! But, even tho the mech. technology was great even back then, the points would float, and wires, & plugs, would give out causing it to start breaking up, usually above 5-6k rpm. (Thank God for HEI) If you read the small block Chevy book, their 327/350hp, & 350/350hp, factory cams were capable of developing power to 7k rpm, and the matching lifters were capable of sustaining it, but you also need the correct springs."

Well, you not the only one on the board that had early SBC experience. For myself, it was a '70 Nova SS w/350. Now it was strong upto 6K. Between 6-7K it would start to break-down. Now, after all this time, I couldn't tell you if it was ignition break-down, valve float or other reason. FWIW, this was a 300HP 350 that had a number of the LT1 parts on it. It did have the hyd lifters. The 6K limit was a "general" rule of thumb, that I remembered from that timeframe. Now, when I looked around the net, there are speciality hyd lifters that may be good to 7K, but most racers seem to be anchored with solid lifters.

Now, can you tell me that valve float, or ignition break-down is a concern with our production marine engines running 5K and under? Do you have a better explaination on where the 1/4 - 1/2 adjustment came from and why it is important on a marine engine?

Just an aside here, I put a 327/350hp cam in a Chevy Monza 262V8 2+2 5spd, because the original cam went round, and it would do 7,000rpm all the time, the tach was like watching a clock, smoothly all the way around, with a 2bbl!,,, no valve float, no misfiring, HEI ignition. Oh, and I've had a few more hot rods, & powerboats, then this.

Now, unless you've done hands on lifter adjustments on many Chevy small blocks, you don't know the advantage of more power (or torque), and faster response to the throttle, that you get with your lifters set at 1/4 to 1/2 turn lash, as opposed to 1, to 1 1/2 turns, then you wouldn't understand,,, it don't matter if it's a boat, or a car, it's still an increase in power. Try resetting solid lifters after they've been run awhile, as you get closer to specs, the idle drops dramatically, and the engine gets lethargic, until you set the idle speed higher, both of these examples are a known fact for anyone whose done it a few times, or more. It works for me, and I don't care what the book says!

 

[Gary H NC]

Re: My rapido longblock (pics)

Update Erick???

The lifter adjusting topic is getting Way too long to read......

 

[MikDee]

Re: My rapido longblock (pics)

"is this standard equipment with marine motors"


Yes, on SBCs anyway.

Are you talking about an extra baffle in the oil pan? or a regular windage tray attached with extended studs off the main bearing caps?

 

[MikDee]

Re: My rapido longblock (pics)

Rapido Marine from the first page of replies, We do adjust valves here but when your lifters get charged with oil , they all change a bit differently. I would do a final adjustment after the first time out so they are fully charged. The adjustment is done by running engine at idle and loosen each rocker one at a time until it flickers or taps then tighten until it stops taping, then take it between 1/4, and1/2 turn more on all valves. thanks and good luck to all of you.. Feel free to call me...Raulll (owner)
786-663-3278 RUN-663-FAST

I would think this guy knows what he's talking about! I would give him the benefit of the doubt,,, besides, he agrees with me,,,

 

[John_S]

Re: My rapido longblock (pics)

"Now, unless you've done hands on lifter adjustments on many Chevy small blocks, you don't know the advantage of more power (or torque), and faster response to the throttle, that you get with your lifters set at 1/4 to 1/2 turn lash, as opposed to 1, to 1 1/2 turns, then you wouldn't understand,,, it don't matter if it's a boat, or a car, it's still an increase in power."

1) I have stated 1 turn, and 1 turn only.
2) Please provide references to ANY articles that support your faster throttle response claims. (hyd lifters only, thankyou)

Nothing on the net that I found indicated that this is the case. If you can't find supporting articles, at least review how they work and explain how it possibly could provide additional throttle response, or lowend torque. If you can't explain it, you don't understand it.

 

[erikgreen]

Re: My rapido longblock (pics)

Well, I know I'm not an admin here, and I do appreciate your input (BOTH of you), but could I ask you to take this discussion to another thread, or to private email?

It's not that discussions here are unwelcome, but judging from your two responses so far I don't think either of you are really going to end up agreeing with each other, so I'm going to have to file the valve lash adjustment topic in the same bin as "what oil to use" and "which is better, outboards or stern drives".

FYI, I decided based on what Raul said (the guy that built my motor) to not adjust the lash until I have it running... I checked it as-is and it seems ok to my inexpert eyes. I'll have a look again after the engine breaks in.

Also, I'll post an update to my build pics later in the week.

Erik

 

[SuperNova]

Re: My rapido longblock (pics)

Well I've been wrenching for 44yrs, and most of my experience didn't only come out of a book, it was hands on, I'd call that practical experience! and I've built a few more different engines then Chevy's, so it looks like you need22more yrs to catch up to me.

And no, my 327 had a (newly designed) high lift hydraulic cam from the factory, till the cam snapped, and I put in a solid lifter "Duntov 2" cam, I'd like to see you adjust that with a feeler gauge statically.

1.- Just sounds like you are stuck in the past to me
1.5.- A 'high lift factory cam is like .410" at the valve. Factory hi-po cams make their power by added duration, not so much added lift. They try to increase the area under the curve and fatten it up as much as they can.
2.-Snapped the cam, huh. Maybe because it wasn't adjusted correctly?

3.-I suppose you adjust solid cam by ear until they are quiet and then go another 1/4 turn as well? Or do you only go 1/8 turn on the solids?

4.- You can bet your arse I know who Zora Arkus Duntov was as well as his life history---but I NEVER heard of a "duntov 2" cam. What were the specs.? I have heard of the 097 Duntov cam also known as the Duntov 30/30 cam which was designed for very early Corvettes with 283's and probably would not breathe sufficiently for a 327 to hit 5000 rpm much less 7000 rpm. But I am able to admit my ignorance--if you can supply supportive examples.

5.- Hydraulic grind cams are not aggressive enough to support the kind of airflow it takes to make any kind of real power above 6500 rpm anyway.

 

[Buttanic]

Re: My rapido longblock (pics)

I once had a professional? mechanic of many years tell me a dual point ignition fires the plug twice. So much for years of experience.

 

[MikDee]

Re: My rapido longblock (pics)

"Now, unless you've done hands on lifter adjustments on many Chevy small blocks, you don't know the advantage of more power (or torque), and faster response to the throttle, that you get with your lifters set at 1/4 to 1/2 turn lash, as opposed to 1, to 1 1/2 turns, then you wouldn't understand,,, it don't matter if it's a boat, or a car, it's still an increase in power."

1) I have stated 1 turn, and 1 turn only.
2) Please provide references to ANY articles that support your faster throttle response claims. (hyd lifters only, thankyou)

Nothing on the net that I found indicated that this is the case. If you can't find supporting articles, at least review how they work and explain how it possibly could provide additional throttle response, or lowend torque. If you can't explain it, you don't understand it.

I'm not going to search the internet, or some book to prove myself to you, apparently you've never physically done this yourself, or you'd see, and know what I mean. Do you get all your info from the internet, or a book? do you follow every rule to the letter of the law? sometimes things work better when you bend the rules. As I said unless you've done this yourself on a regular basis you don't understand, if you haven't seen for yourself the difference, I can't explain it to you, I don't know how or why it works, it just does, and I doubt you're going to find the answer on the internet, or in a book! No, I refuse to be put on the spot just to please you, So, you can either take my word for it, or not, or try it for yourself and see.

Just remember the tighter you make the valve adjustment, the more chance you may "stuff" the valves (leave them hanging open away from their seats, or on their seats for too long a time, overheating them) neither of these are good!

 

[fendersfender]

Re: My rapido longblock (pics)

OK OK already...hes probably got the engine in the boat.....give the lifter issue a break already.........

 

[John_S]

Re: My rapido longblock (pics)

Sorry Erik,

I have moved continued discussion into another thread. http://forums.iboats.com/showthread.php?t=220365 BTW, in case you missed it, I did recommend you follow the builders advice, so ther won't be any warrante "discussions". good luck, and will look forward to the additional pictures.

 

[MikDee]

Re: My rapido longblock (pics)

1.- Just sounds like you are stuck in the past to me
1.5.- A 'high lift factory cam is like .410" at the valve. Factory hi-po cams make their power by added duration, not so much added lift. They try to increase the area under the curve and fatten it up as much as they can.
2.-Snapped the cam, huh. Maybe because it wasn't adjusted correctly?

3.-I suppose you adjust solid cam by ear until they are quiet and then go another 1/4 turn as well? Or do you only go 1/8 turn on the solids?

4.- You can bet your arse I know who Zora Arkus Duntov was as well as his life history---but I NEVER heard of a "duntov 2" cam. What were the specs.? I have heard of the 097 Duntov cam also known as the Duntov 30/30 cam which was designed for very early Corvettes with 283's and probably would not breathe sufficiently for a 327 to hit 5000 rpm much less 7000 rpm. But I am able to admit my ignorance--if you can supply supportive examples.

5.- Hydraulic grind cams are not aggressive enough to support the kind of airflow it takes to make any kind of real power above 6500 rpm anyway.

1) Ok. smart guy! the 62' 327/300hp motor was the first engine to have the .390/.410 high lift hydraulic cam, it paved the way for the standard plain vanilla stock Chevy 327/350 cam!

2) I'm sorry No, this just happened a little while after I got the car, the engine was untouched by me at the time, I got it with 40k miles on it.

3) .008-.018 with a feeler gauge with the engine warmed & running.

4) The original Duntov cam was used on the early 55-57 vettes, the Duntov 2 cam was used on the later 283, and the early 62-64' 327- 340, & 360hp corvette engines, look that up in your book! I don't have the rest of the specs memorized as it was a long time ago, maybe (.393-.398 lift, duration?) but suffice it to say the lift, & duration, were not much different then the O.E. hyd. cam, unknowing to me at the time, and I had a chance to get the "30/30" cam then, and thought it was too radical, I wasn't sure if my pistons were notched, (they were)! $32.95 for the Duntov 2 & 16 solid lifters, mechanics discount from the Chevy dealer at the time!

And finally, I think it was 65', that the 097 "30/30" cam came out, called that because it had .030 intake & .030 exhaust lash, it was .480/.480 intake & exhaust lift, and 310 degrees adv. duration. It was the cam I drooled over, with a clicking lumpy idle, and useable power up to 7000rpm. It was used on the 327/365hp corvette with a 4bbl, And the 327/375hp vette with fuel injection. So you see, you're not as knowledgable as you think, ("The "30/30" cam was probably not used on the 327", Ha!) Yeah, the orginal Duntov cam was hotter then the Duntov 2, (a crappy one). Around this time, the 327/350 Hi lift hydraulic came about, it was used in the 327/325hp Chevy 11 Nova, with 10X1 compression, and 327/350hp in the vette with 11.0X1 compression another great cam with .447/.447 lift, and I believe 287degrees duration. A while later when the 350 became the std. engine, the 350/350hp Hi lift hydraulic cam came out with .450/.460 intake, & exhaust lift, and a bit more duration then the earlier 327/350hp cam. and with that, I'm done here on this subject!

 

[FreeBeeTony]

Re: My rapido longblock (pics)

Almost sorry I asked the question..............

Looking forward to seeing more on erik's progress...........

I will also start a thread when I get my engine from Rapido..........

 

[SuperNova]

Re: My rapido longblock (pics)

Almost sorry I asked the question..............

Looking forward to seeing more on erik's progress...........

I will also start a thread when I get my engine from Rapido..........

Just don't ask any questions about piston design or deck height....please??!?!? You see what trouble you already started--This is almost as bad as those political discussions they have in the dockside chat area of the forum......nah, maybe not that bad...

 

[Daddy O]

Re: My rapido longblock (pics)

I've tried this method, and the lifting the pushrod up, & down method, ended up with valves out of adjustment, Maybe on a brand new engine, with all nice shiny new parts, and no wear, or built up gunk, but not on used, or rebuilt engines, from my experience. My final adjustment comes with the car warmed up, & running, and following the clicking.

I also did it on engines that had ran the 1000's of miles not just brand new engines ( from new to used, and even rebuilt). Every 100 hours of engine testing we did a cylinder leak down and loosened all the rockers. After that we lashed the vavles. That was per GM engineering.

 

[MikDee]

Re: My rapido longblock (pics)

Well, I know I'm not an admin here, and I do appreciate your input (BOTH of you), but could I ask you to take this discussion to another thread, or to private email?

It's not that discussions here are unwelcome, but judging from your two responses so far I don't think either of you are really going to end up agreeing with each other, so I'm going to have to file the valve lash adjustment topic in the same bin as "what oil to use" and "which is better, outboards or stern drives".

FYI, I decided based on what Raul said (the guy that built my motor) to not adjust the lash until I have it running... I checked it as-is and it seems ok to my inexpert eyes. I'll have a look again after the engine breaks in.

Also, I'll post an update to my build pics later in the week.

Erik

I'm Sorry Eric that I hijacked the thread, I was only trying to help, then got carried away defending myself, I wish you the best with your boat, & progress, it's looking good! I think you can't go wrong if you listen to Raul.

And to Imported john, Supernova, and the others who posted, Peace brothers!

 

[FreeBeeTony]

Re: My rapido longblock (pics)

Any news erik?...........Is it running??