TZ, what's the specs on cam, if you don't mind.

 

Sure...

Lift: .570 int / .556 exh

Duration @ .050: 239 int / 243 exh

LSA: 112 lsa, 4 degrees advanced.

Running it through my copy of Engine Analyzer and using some basic settings for the cam (dwell over the nose, some other info regarding ramp speeds, etc.) shows a 25 HP increase and roughly 700 RPM increase for max horsepower. The spread between max torque and max horsepower is a little narrower, and using the formula of propping for 1K RPM over max torque would put me beyond max horsepower. But then again, this is just a simulation. Most important is the fact that EA does a great job of plotting actual RPM trends (though it can be conservative with power output).

My parts will be in Monday or Tuesday. I'll probably have the cam back in tonight or tomorrow morning. Then it's just a matter of getting the covers back on. I'm hoping to run it next weekend. The only worry in the whole thing is push rods. This cam was ground on a small base circle. I don't think that the original Comp cam was on a small base circle, but I could be wrong. I'll have to put it back together and see what's what. Pushrods would set me back a little in terms of time.

Tom

 

Congrats Tom. I've echoed it alot before but Bob is a standup individual and an asset to the performance marine world. Anyone thinking of changing a cam or upgrading their engine should talk to him first.

I like those specs. It's the bigger brother of mine. Mine is a 234/240 .580/.568 112+4 also. I love it. Idles 850rpm N, 650rpm in gear idle and will rev out to 6300 still holding power. Get ready for alot of testing to dial in the new setup.

What rpm did Bob think it will peak at? Any plans to reprop to achieve desired rpm?

 

All of my parts are in. Woohoo!! Now I just need some time to work on everything.

I'm ready for the testing! I've followed a lot of your specs in terms of coming up with a baseline on some things so I think I'll be close (in fact, I think my Stinger's hull design is based off your Challenger ).

Bob's idea was to replace the XR282 with his design as well as ditch the Air Gap for a single plane (I'm using a 7530 Team-G with a 1-inch HVH spacer to increase the plenum volume). The plan is to spin this baby to 6300 and he's pretty confident that we'll be on target.

As for the prop, I'm really happy with my 23P Turbo (though my Mirage Plus 25P gave me my fastest speed... it was a PIG!), and it needed I'll have this one adjusted. I also have a Hydromotive 24P 3-blade that could be worth a try again (I wasn't happy with its performance the last time I used it).

It's going to be a fun and interesting summer!

TZ

 

Cam is in. Did my pushrod checking and they definitely need to be replaced. I looked at everything very carefully and decided to grab one of my spare pushrods from the Brodix 355 and low and behold, they work! Perfect!

Tomorrow, I'm off to Virginia Speed to pick up a set of Comp 7638 pushrods (LS1, Virginia Speed does a TON of work with LS1s and keep them in stock... just my luck!).

I should have the engine running at a baseline by the end of the weekend as long as I don't have to work (end of our fiscal year... sales folks are going crazy!).

TZ

 

No updates... I had to go to the ER Friday morning. My asthma was going crazy and my rescue inhaler and my nebulizer machine weren't doing much good. Come to find out, I have pneumonia! I wouldn't have know it either unless I had gone to get help with the asthma. No wonder my breathing was all messed up! No fever or anything. Just a nasty cough, no energy, and a very tight chest.

I'll try to get back on the horse this week. I'm at the office today even though my Dr. said that I should be in bed for a few days (mandatory software updates that need to be in before the end of the month). I'll rest when I'm dead!

On a positive note, Virginia Speed had my pushrods so I have everything. I just need to swap the springs, clean up the gasket surfaces, and put her all back together.

TZ

 

Get well soon. Lets here that thing when shes running.

 

Thanks. I'm going to try working on it a little tonight. The biggest job is swapping out the springs. Once that's done, then it's smooth sailing.

 

Guess I have a sh!ty "on the engine" valve spring compressor because it was NOT working! I need to go out tomorrow and get one of the simple leverage-type cheapie deals. I managed to get one valve spring off. One. And there was no way with this tool that I would have been able to get the new springs on.

What a waste of time.

Oh well... tomorrow is another day!

 

This is the one I have and it works killer! but they are a bit pricey.

http://www.summitracing.com/parts/LSM-SC-200/

 

I'm going to use the lever version. I can almost make one!

 

Hey Tom, not to tell you what to do but take it to a engine machine shop, they will have them on in about 5 to 10 minutes with there air C clamps. I have the manual compressor also, they work but take forever and don't take a chance of not getting the locks set in properly. Good luck anyways.

 

That would require a tear down to get the heads off.

I'm very confident with this kind of stuff. It won't be an issue getting the springs off and putting the new ones back on. I've done this many times before. I think that the on-the-car compressor that I have is just worn out.

I'll be back at it tonight as long as I can breathe. The pneumonia is still a factor I guess.

 

Made some good progress last night (worked on it until 1 am!).

My Cloyes timing cover is rebuilt and installed and the balancer is back on. All of the gasket surfaces are clean and ready for installation.

I ordered a new spring compressor from Summit so that should be in today. Once the springs are in, final assembly should be quick!

TZ

 

Doing the old air in the cylinder trick. Did that a few times. I originally thought the heads were off.

 

No air... I'm using rope.

I have to do a lot of this late in the evening so firing up the compressor is a no-no (my daughter's bedroom is within too close a proximity to the garage). I can't even speed up stuff using air on this one... all hand tools. Not too bad though, I'm very quick with my tools.

 

Well, the Summit tool worked like a charm! Got the new springs on last night and started buttoning up the rest of the engine. A couple of hours of work and we should be golden.

 

Most of the set up is back together. Just a few more things left to do... the biggest being the damn cam button cover. The rest is just bracketry.

I'm going to throw my small Laser on the boat for testing... hopefully Friday.

Question... do you guys run a thermostat or a restrictor in place of a thermostat? I remember from last year that switching to a thermostat (from the restrictor) seemed to raise my oil temperature/drop oil pressure when she got warm (150-160 degrees)... and I don't like that.

 

I just did a 427 with a cam from Bob (Marine Kinetics) ant this engine rips. Were pushing 550hp from this little big block at 6000 RPM and the cam is loppey at an idle but has dock manners. This cam has .634"/648" great cam. FYI spend the cash and use the PBM Moral lifters ther hold up well to agressive cams.