Null

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - obnoxious001

Pages: [1] 2 3 ... 19
1
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: February 01, 2016, 09:21:56 PM »
Quote from: Reefmoto on February 01, 2016, 09:12:40 PM
I'll look into stroker crank, but it's hard to pass up a 200 dollar forged crank... maybe I'll throw some nitrous on it to make up for non stroker

All things being equal, on a pump gas engine you may only see about 40 HP difference for the difference in cubic inches.

2
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: February 01, 2016, 08:58:40 PM »
Quote from: Reefmoto on February 01, 2016, 08:55:32 PM

Really, not to late... but at the same time I'm getting a smoking deal on a forged 4"crank ($200)

OK, that's a good deal, but as I said, I put lots of them together, only one I had to do some grinding on was a 2 bolt block.

3
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: February 01, 2016, 07:37:24 PM »
Quote from: Reefmoto on February 01, 2016, 07:34:51 PM
Well decided to buy new dart cast heads, also bought some forged dome top pistons and bought a forged 4"stroke crank. Didn't want to do a stroker crank because I would have to do more machine work. Now I'm searching for thru transom  tubular header, and a eddlebrok Victor intake mani single plane.

Arg, wish you would have checked with me first, most GM 4 bolt blocks have enough clearance for a 4.250" stroke crank with H beam rods, no problem.  Once you are buying new stuff, cost is the same, but you gain cubic inches.

4
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: January 25, 2016, 10:27:58 PM »
Quote from: Reefmoto on January 25, 2016, 10:15:20 PM
Yep waiting on price for the marine 502 heads, they are bone stock heads straight from the factory/machine shop ready to go (will go to machine shop to be measured). Waiting for price, what do you guys think?

See my comment above, the 049's are honestly probably better for a jet boat engine.

5
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: January 25, 2016, 09:57:11 PM »
Quote from: Reefmoto on January 25, 2016, 07:24:12 PM
I'm shooting for 9 to to 1

9.5 to 1 is still ok with iron heads.  My advice is to make a firm decision on which heads you are using prior to purchasing pistons, so you can calculate compression ratio.  You won't have an exact deck height measurement without having a shop measure and tell you, or actually mocking up the assembly in the block with one piston and rod, but can probably get close.  If you want some help figuring out compression ratio, there are various calculators online, or ones you can download. 

Once you have heads and decide on which pistons to buy, while the assembly is being balanced you can start thinking about camshaft, but not before you know all the parameters of the engine you are building.

6
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: January 25, 2016, 05:40:30 PM »
Quote from: Reefmoto on January 25, 2016, 05:00:27 PM
Thanks for all the input! right now I am going to reuse my stock crank/rods, and peanut ports are out. I am going to be purchasing a set of nice forged pistons this week and will hopefully have some new heads this week as well. I found a pair of 1256 2934, but need to do more research on them. they came off a running 7.4 but dont know if they would be worth it or should i just find some 049's

The 2934 head is a 502 rectangular port head.  Likely you will do better for a non-race jet boat with oval port heads, if you plan to make moderate power and run in the 5000 rpm range.  The rectangular port heads are better suited to higher rpm or larger cubic inches,  or both.

As I said before, if you were going to spend any money on new bolts and resizing your stock rods, it makes more sense to just buy a set of Eagle or Scat I beam rods that use a 7/16" capscrew. 

7
Boats For Sale / Re: 1975 Liberty Compjet
« on: January 24, 2016, 02:02:40 PM »
Quote from: GT Jets on January 24, 2016, 01:27:28 PM
Holy crap.

Thanks bud.

Seriously waiting to get the fun tickets together and for the Comp Jet Class rules to settle out.

My other Comp Jet racer that I build for uses "fun tickets" as well.  He had more of them available, we made an honest 800 dyno horsepower out of his single carb engine that has not gone into a boat yet. 

I don't claim to be super knowledgeable about jet boats, but have built several different Comp Jet engines, each a different combination.  My understanding is that pumps work well in this type boat until about 6200 or so, and I don't see that as a problem for a well built 4" stroke engine.

I hear you on the rules stuff, hope not too many people get all negative and quit racing with the capsule rules that got voted into effect for several of the other classes.

8
Engine Mechanical / Electrical / Re: motor is at the machinists, need advice
« on: January 24, 2016, 12:42:10 PM »
Quote from: Reefmoto on January 20, 2016, 09:29:30 PM
I have a 454 that I am boring .030 over, It is going in a 21' commander with a jet. I will be running stock heads( they will be decked and match ported, they are ☆ peanut port ) and it is a gen 5 block. I need a rotating assembly and have found a bunch online. I have heard to pick my parts but in my case I think a " kit" would be best. what are your thoughts on the skip white kit?
http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368

this seems like its the best bang for my buck, I was also looking at the summit racing
http://www.summitracing.com/parts/sca-1-92249

thoughts? i know ring gap and being able to hold high RPM is key for a jet boat motor and i think these kits would be best for my application

If you are on a budget, and not looking for big power, why not a used GM crank?   Then maybe some aftermarket I beam rods with cap screws instead of stock through bolt 3/8" GM rods, and forged pistons, get them all balanced with damper and flexpate and good to go.  You would be better off spending the money saved on some better heads, the peanut ports are going to hurt your power output. 

I have been considering putting together a "budget" stroker build, with an aftermarket cast crank.  Why spend the money for a new cast crank and not increase displacement?   

Ring gap is important in any engine, you can't go tighter than recommended minimum gaps, slightly looser (as in non-file fit rings) won't kill you.   Bearing clearance is more critical and needs to be measured rather than assuming that if the crank turns it will be fine.

9
Boats For Sale / Re: 1975 Liberty Compjet
« on: January 24, 2016, 12:36:59 PM »
Quote from: GT Jets on January 24, 2016, 12:18:47 PM
At what RPM does she like?

 The engine was build with the goal of setting the boat to run in the 6200-6300 range

10
Boats For Sale / Re: 1975 Liberty Compjet
« on: January 24, 2016, 12:00:39 PM »
Quote from: tpltrbl303 on January 09, 2016, 03:09:40 PM
Race ready – Very fresh Barry Obler engine
$12,999 Complete.  Would consider seperating
I will PM all the specs to interested buyers

I am available if someone wants to know anything about the engine.  It is a "race" engine, extremely low hours (assembled and installed just before the Parker race last year), high compression 468 with new Eagle H beam rods, 4 bolt block, brand new aluminum heads, solid roller cam.  I drove the boat one time during engine break in, it's stout!

11
Engine Mechanical / Electrical / Re: Flexplate wobble?
« on: March 28, 2015, 03:30:23 PM »
Do yourself a favor and buy an SFI rated flexplate, they are a little thicker and some are not too much money (hint: try Summit brand). 

12
The Parker Strip / Re: Blown head gasket
« on: March 28, 2015, 12:22:26 AM »
Quote from: 79 ranger jet on March 27, 2015, 11:49:22 PM
Shhhhhh don't tell anyone lol hopefully we can get rob going too

Looks like maybe just one spring was off a brush in the starter, will see in the morning with a hot battery.

13
The Parker Strip / Re: Blown head gasket
« on: March 27, 2015, 11:34:54 PM »
Quote from: 79 ranger jet on March 27, 2015, 11:32:55 PM
Barry I really appreciate your help without you I would still be trailered thank you my friend

Glad to help.  I still think it's pretty darn funny that you have a GM pushrod in your Ford now!  See you tomorrow.

14
The Parker Strip / Re: Blown head gasket
« on: March 27, 2015, 11:31:38 PM »
Quote from: 79 ranger jet on March 27, 2015, 11:26:56 PM
Hey if it wasn't for this site I would artillery be trailered I am very thank full for this site


Now to see what I find in Rob's starter.  Got his battery on the charger so it should be good to go!

15
The Parker Strip / Re: Blown head gasket
« on: March 27, 2015, 04:01:09 PM »
Quote from: 79 ranger jet on March 27, 2015, 03:59:36 PM
bent 2 push rods pick up tomorrow at 7 hopefully be on the water by 9

Guess you took it to a shop, sorry I didn't catch you sooner, might have had pushrods here.

16
Engine Mechanical / Electrical / Re: Engine dynamics
« on: March 27, 2015, 01:30:38 PM »
Quote from: sonny1717 on March 24, 2015, 10:27:10 PM
Hey guys - dropping the float off at engine dynamics tomorrow in Baldwin park. Anyone know about this place? - looking to have them fine tune it. Everyone seems to recommend them. Who does everyone else use local to the IE ?

You do realize he tunes for Dave Rankin?  Dave's circle boats records speak for themselves, John Avery knows what he is doing.

17
The Parker Strip / Re: Blown head gasket
« on: March 27, 2015, 01:27:44 PM »
I can help you, about 3 miles upriver

18
Engine Mechanical / Electrical / Re: 454 rebuild gen v
« on: September 28, 2013, 11:13:24 PM »
If you didn't buy the pistons yet,, I need to ask why you want to make the compression that low.  Flat tops with 118cc heads are still about 8-1 compression, depending on deck height and gasket volume.  I would consider making it more like 9-1 compression, still safe on pump gas but some additional power.  Also, I normally would advice forged pistons rather than hypereutectics for a marine application. 


19
Engine Mechanical / Electrical / Re: Carburetor HELP
« on: September 28, 2013, 11:02:36 PM »
What's been overlooked here is that he is running 5000 RPM with the A impeller.   

Some years back I built a mild 454 for my friend's jet boat that also turned an A impeller 5000 rpm, showing about 62 mph on a non gps speedo, but routinely beating 18 foot jets with headers, while his 20' open bow had through transom exhausts and covered engine.  Made lots of guys mad.

The engine was installed into the boat with the 715 cfm (Yes, Holley made them) OEM carb, and did pretty well with it.  One day he ran out and bought an 850 Holley without asking me first, and was surprised that the boat actually lost power until he and I did quite a bit of messing around with jetting, and in the end made no actual gains. 

I have built some comp jet race engines that were turning smaller impellers into the 6200-6500 rpm range that did run single Dominators, and one of them out-powered the tunnel ram boats at Burley badly enough the other competitors were talking about protesting it.  I assure you the engine was 16 cubic inches under the maximum allowable limit, with absolutely no porting in the heads or intake, they both still had APBA spec lettering in them.  That particular boat didn't do well in rough water, or it may have shown similar results at other races.  We are in the process of rebuilding that engine with new heads, and the ultimate plan is to dyno with both single Dominator and tunnel ram to determine the actual difference, but if the impeller limits an engine to a given RPM below it's actual maximum horsepower, larger CFM rating may not be doing much for it?

20
Engine Mechanical / Electrical / Re: 540 build advice
« on: August 25, 2013, 08:57:45 PM »
Quote from: santeerob619 on August 23, 2013, 10:33:27 AM
I'm looking at a bow tie block right now with a 4.5 bore. I already have a brand new 4.25 Molnar crank and 6.385 rods. With that bore and stroke it will make a 540. The guy is also selling a set of 681 casting bow tie heads. They are 105cc open chamber heads with 380cc intake runners! Will that be a good head for a 540? I want to run a tunnel ram with dual 850s and a roller cam. Possibly a blower, but most likely a tunnel ram. I'm looking for advice.

Sent from my DROID RAZR HD using SoCalJetBoats mobile app

Yep,, those heads are not for you. 

Is $1800 for a new bowtie block, or used?  If not, do some searching for Dart blocks, there have been some really good prices in the past couple of months. 

21
Engine Mechanical / Electrical / Re: Jet boat slowed and motor stopped *HELP*
« on: August 19, 2013, 03:17:12 PM »
Quote from: Trukinbear on August 19, 2013, 10:59:54 AM
I wouldn't reuse a block that ate 2 cams so quickly either. I'm not saying that a naturally aspirated BBC can't make 700hp - but I'm pretty sure that this random collection of parts didn't, and it sounds like your builder doesn't have a clue either.

I will bet another 5c that the cam didn't break until the debris from the other destruction got into it and jammed it up.  The photo of the cam and lifters is not quite good enough for me to see any other damage than the breaks, which are common when pieces of iron and aluminum and exhaust valve are bouncing around in the crankcase, being batted around by connecting rods.  He stated it lost power(that would be when the valve let go, taking out the piston and cylinder wall) , then after that quit running (when the cam snapped)

The block appears to have a big hole in the cylinder wall, not to mention damage at the bottom of the two cylinders.  It may not be a candidate for the rebuild, but I think it's pretty hasty to say that it "ate 2 cams"


22
Engine Mechanical / Electrical / Re: Carb suggestions ?
« on: August 19, 2013, 01:48:43 AM »
Quote from: MID-LAKE-CRISIS on August 18, 2013, 11:34:34 PM
  stock 350 SBC swap out (finances dictated)
  not liking the Rochester quad
  pushin 4200rpm max pedal (Panther)
  suckin fuel like a crack$hore
 
  checked Holley site , recommended 650 DP marine app.

  any and all suggestions/opinions appreciated

  thx

Interesting that they suggest a 650 cfm carb, at 4200 RPM you are not moving that much air.  If you don't intend to increase performance or modify the pump for more RPM, you might even find something as small as a 450 cfm Holley would work fine.  Many years ago (in the late 70's) when I worked for Gale Banks, the engine builder was a real Ford type guy, and he used to run them on 460 Fords for his customers for street use, citing throttle response and fuel economy. 

I am reasonably certain you don't need or want a 750 on a very mild 350 that is running low RPM.  We run a 750 on various size small block Chevy engines that we routinely run over 7000 rpm in a circle track car. 

You can also call Holley on the phone and talk to a real person and get additional feedback. 

23
Engine Mechanical / Electrical / Re: Jet boat slowed and motor stopped *HELP*
« on: August 19, 2013, 01:39:04 AM »
Quote from: Trukinbear on August 18, 2013, 11:31:48 PM
Personally I think that .090 over is a tired block, unless it was a Dart or Bowtie block. And I agree that your 2 events are related...it might be cheaper to replace the block. Perhaps a lifter bore is worn badly, or is oversize? That would explain eating the lifter and pushrod, along with the cam lobe.

.090" over is not a size that KB makes in hypereutectic, as far as I know.  I had asked him to get more particulars on the pistons.  I also have some personal doubts about 4.5" stroke, since it would require lots of grinding for clearance in a stock GM block, maybe not even possible without hitting water jackets, and from what I can see in the photo, there is no grinding, so I have to guess it's a much more common 4.250" crank, with .060" pistons (he did state that it was originally .030")

That being said, I personally have run a .100" over block stroker motor, 505 cubic inches, with first an 8-71 blower, and later a Gentry turbo setup making 15 lbs of boost.  I raced the block for 6 years once the turbo kit was on it, took it apart after the boat was sold (less engine), then rebuilt it again for the guy that bought it from me. 

While I have to rely only on photos of the broken parts, I am still waiting on more information about the piston part number and/or dome volume to see if the static compression is what he was told.  I still think the cam was broken due to pieces of piston, valve and block (look at the bottom of the cylinders) bouncing around inside the crankcase, being batted around by a lose connecting rod. 

Until there are more facts and evidence, I continue to stand by my previous statements, I have seen too many engines come to me with the head of the valve broken off like that.

24
Engine Mechanical / Electrical / Re: Jet boat slowed and motor stopped *HELP*
« on: August 18, 2013, 12:44:52 AM »
Quote from: rivermikey on August 17, 2013, 03:23:55 PM
I do faluire analysis for a living and  By looking at the pics you have....valve keeper was not installed correctly.... You had to be revving that engine above 3000 rpm, valve dropped, impacting the top of the piston crown their cast aluminum pistons they will shatter if hit hard enough.........

The valve stem is still in the guide, no photo of the top of the head to say whether the retainer is still intact, but I bet a nickel that it is. 

I will stand by my initial guess, have PMed the original poster for the rest of the engine specs, thinking it may have had some detonation or pre-ignition problems.  It's very common for a marine engine to lose an exhaust valve under those circumstances, then the head of the valve can do similar damage to what the photo shows, and parts then bouncing in the crankcase can get up and jamb up the camshaft.  He stated it lost power (hmm,, missing exhaust valve head, and broken piston would definitely kill power,, then when the cam broke it would stop running, unless the rod happened to jamb itself into the block first, which apparently it did not.

25
Engine Mechanical / Electrical / Re: Jet boat slowed and motor stopped *HELP*
« on: August 16, 2013, 09:25:58 PM »
Quote from: MPKardell on August 16, 2013, 09:36:31 AM
What's the stuff on the intake valve (next to the missing exhaust valve)?

Gotta think that's aluminum,, look at the rest of the chamber, and don't forget how many pieces the piston was in.

Pages: [1] 2 3 ... 19

Null

SMFPacks CMS 1.0.3 © 2026