I don't know what stock 325hp marine engine came with roller rockers. It really depends on the cam profile. Dual pattern really doesn't mean anything for practicality. My question would be are they self aligning rockers for vortec / centerbolt heads, or are they for heads with guide plates? What style do you need? $375 doesn't seem bad if they are full roller rockers. The way I would look at it, if it is some stock cam, you are taking it off his hands. You are only buying the lifter / dogbone / spider assembly (if OEM style) and roller rockers (roller trunion and tip). The pushrods / springs may not work for you if you depending on your machine work. If you can offer up more equipment details, we can better help.

SB, I like that combo you put together. Decent cam with good flowing heads. Completely believable speed increase. My old Searay 18'6" transom length 20"2" LOA went from 56 to 63 with ported stock centerbolts, comp flat 260H, performer intake and Kodiak exhaust. Stepping up to a 383 with the 212/218 extreme energy hyd roller and trickflow heads bumped it up to 68-70 and the Alpha SS bumped it to 75. What hull are you working with?

I currently have on the engine stand a Merc 6.2 MPI that has been converted into a 383.
3.750 stroke
6.000 rods
4.030 CP Pistons
Profiler 190 Heads
Holley Stealth EFI
Marine Kinetics Hydraulic Roller
This is the next engine up on the dyno. I will let you know and post dyno results. If you are looking for a cam, the only recommendation I will make is call: Marine Kinetics.

:(

He's gone from here now - last night or this AM. Got booted out by the admin. That's 2 offshore sites he can no longer peddle parts out of and ruin people's boating hobby / sport. Thanks for coming clean with your experience.

You know me. I'm CFM from the other boards. Many eons ago I signed in here before the others. Thus the different name.
That boat went from 53/54 to 68.7mph. I'm going to hang a SS on it this or next year (secured a broken one this winter...lol) and see if I can get this million hr beat on hard 5.7 shortblock over 70.
Has the making for a stout build. What kind of boat is this going into ?

Last time I checked a 6.2 was a 383. What did u convert??

Ah SB=CFM didn't realize that. So the Mirage. I thought that boat only went like 45 or so...

I think a stock 6.2 is a 377"

6.2 MPI is 377 CID

38 actually. 45 is our speedlimit. :D

x 2.

Stock bore 350 with 3.75 crank? I see.

I'm not sure about the roller rockers either. He asked what I had for rockers and I told him I had planned on buying Yella Terra shaft mount roller rockers. I'm an old Mopar guy and never had rocker issues running solid lift cams on the street and could go months with out needing to adjust the Harland Sharp shaft mounted roller rockers. A friend of mine who race's at the local dirt track said he had tried all kinds of roller rockers on his sbc finely tried the yella tarra shaft mount rockers which put an end to rocker problems he had fought.

I didn't take into consideration when I started this 383 build restrictions like the stock logs or how much I could exhaust out the prop and as I said earlier in the thread the good paying job I had when I started this project is gone. Un-less I can find some decent exhaust manifolds for a good price I guess I need to finish this build with more of a stock tone or camshaft in this case that's not going to choke the engine due to restrictive exhaust. I'm not a chevy guy so I couldn't tell you what the EQ 23degree heads require. Supposedly they are ready to bolt on right out of the box. They are the 180cc runner performance EQ head with 202 and 160 +.100 valves and fast burn 64cc combustion chambers. They used molds from ported ports on both intake and exhaust runners.

The bottom end is a 98 4 bolt vortec block bored .030 over. Mains line honed with new ARP main studs. I went with RaceTec forged D dish -21cc and valve reliefs for 570 lift cam on 5.85 Oliver steel connecting rods and coated ACL rod and main bearings.I decided on the coated bearings after looking at opened up bottom ends of drag motors run all season long. All the coating was still on the bearings. No steel on steel after being run hard all season. The bearings actually looked like they had not been run at all. The deck was cut down leaving the pistons .005 in the hole. The Crank is a 3.750 forged and nitride Kellogg for 1 piece 5.7 GM block. Block was ground and clearance checked and bottom end internally balanced. My machinist calculated compression to be 9.3.1

How much do the Kodiak manifolds cost that I read about in this thread?

I had talked to my machinist yesterday about the new take offs of the marine engine, roller cam new roller lifters the spider thing, another one of those Chevy things lol. He does mainly race engines is not a marine engine guy but I asked what he thought about the cam and he said likely lots more torque in the 383 and a loss of top end rpm's.

My boat is a Glastron gs205 and dry weight of 26 or 2800 lbs. I scored a Volvo SX duo prop off a 2007 sting ray to replace the single prop SX cobra that came with the boat. I have not bought props yet. Any idea what mph this boat might be good for?

It does concern me that the take off parts may not be mercruiser. Another idea I had was to look at mercruiser engine packages exhausting out the stock logs and buy the part number of the cam used in that app. I think I saw a 383 Mag rated at 370 H.P. I'd bet my heads are as good or better than what they used on that package.

383 divided by 61.023 is 6.27 liters
377 divided by 61.023 is 6.17 liters. Close enough....

That's what I was going by. Had me thinking I lied to my friends about my last few 383 builds I done. I told them they were 6.2 liters!!

I just finished a 383 build and I am very familiar with this whole process. I shared all my info every step of the way and had some very good results. The idea of going to 383 for a performance gain but doing it through the prop seems beyond silly when I know the expense involved.

If you want performance from a 383...you can't go through the prop. I'd just find a cheap used 6.2 and call it a day.

So dropping down to a 377cid will make all the difference weather a stroked small block will work or not? I have been talking about a more factory type cam just to be able to use the 383. Not what I had intended when I started this build but something I may have to do because of what I have learned in this thread about the stock restrictive exhaust.

Question about GLM exhaust manifolds. I have read these are a Chinese knock off of the Kodiak manifolds. They claim a 10% increase in flow. Would these be an improvement over my stock logs? And if so could I run a tru hull exhaust with the ability to exhaust through the stock leg at times when wanted?
http://www.ebay.com/itm/Volvo-Penta-...198c5a&vxp=mtr

I was saying buying a stock 377 might be cheaper and perform better than going through all the expense of a 383 build where you don't do it right.

I have the GLM manifolds on my build, we used those and some taller stainless risers. Because of that Bob Madera was able to make a bigger cam and build some more power.

Think of it this way, you can put anything on those exhaust ports and it won't matter because you are choking it with the through prop exhaust. When I switched to my 383s, I got rid of my through prop exhaust because it restricted my power, I also got rid of my captain's call. I had to do both of those things to make the power I wanted. I'm so glad I did! I'm very pleased.

I think I have one of the stronger 383 builds on the board, if you want to read what "recipe" my engine builder and I developed, here's my thread:

http://www.offshoreonly.com/forums/d...d-project.html

Thank you. That was exactly info I was looking for. How much will I hurt my performance running the captains call but still using the GLM's and tru hull exhaust? And can I run stainless risers with this set up? I'm checking your thread out now. Thanks for the link.

Tough to say, I think there's more experts on that question in this thread. But I can say when I was making my decisions, if I kept my captain's call Bob Lloyd pretty much laid it out for me that I wouldn't be able to get a big enough cam to make anywhere near my power goal. It was pretty much a foregone conclusion that we were ditching the captain's call.

C'mon, it sounds awesome :) I also don't feel like a jerk being loud anymore around the docks...because I have no option now!

How will me and the kids sneak up on the fish? Lol I will have to have the captains call. We have some pretty up tight folks here in Kansas. Good luck has come my way this week as we have gone back on overtime. I will order my GLM's next Friday then start talking cams again. I will be running a carb on this engine by the way. Overtime permitting i'll give Bob M a call about a grind for mine. I'd almost kill for 400 H.P. I have just a hair more compression on my build and head wise we are probably real close. Thanks again for the info.

You're going to have a WAY easier time tuning...at least a lot less time and money spent on shipping ECUs! That's nice. Compression should be a benefit for sure. Just make sure you have an improved intake, that's key. You probably also read about throttle body, if you can do that cheaply you're going to make a good chunk more power we found.

Just for FYI on this discussion. I just finished dynoing another 6.2 build. It's an early model 6.2 with the 4 bbl type intake. I rebuilt it with forged pistons. Raised the compression to around 9.8. Minor bowl work on the Vortec heads. We used a Comp 270 hydraulic roller. Stock exhaust with stainless replacement risers. It made 380 HP at 5700 RPM, and over 370 from 5200 on up. Torque was 423 at 3900 RPM.That leaves a 500 RPM window from 5200-5700 where the power is pretty much flat. So as with many other 6.2's I've done, that head, cam and exhaust package works really well but pretty much hit it's limit by 5400 RPM, but if you want to turn more rpm it doesn't completely just die, just no real benefit.

Hope this helps,
Bob Lloyd
Full Throttle Marine

I ran my first 383 with trick flow twisted wedge G1, 10:1 comp, CS XE264HR-10 212/218 hyd roller and the Kodiaks through the drive and when I finally put through hull on it, you know how much I gained????? Nothing but better sound. REalisitcally that was probably 330-350hp (corrected) to the prop (around 410 at the motor) and it didn't make a difference. I don't know how much more restrictive the Volvo transom is, but with a cam comparable to that I would just run it through the prop.

Here is my dyno run with the XM276HR 224/230-112 I then changed it to. This was a comparison of the dyno headers vs Kodiak manifolds (wet).

http://imagizer.imageshack.us/v2/xq90/34/61y2.jpg

Opps... This is with my RMBuilder cam 234/240-110 .560 lift.

My 276 cam made 437hp@ 5400RPM and 479 lb-ft at 4100 rpm though dyno headers. Edel RPM and q-jet.

My early plans were EQ vortec heads and I know they work well but I got side tracked with another EQ head, the 180cc performance head and decided to try something different then the vortec route. I was re-assured the 180's would flow better and still make as much or more torque . This build is slow going on account of job change but I can kind of see the light at the end of the tunnel. I'll post numbers when I get that far along and see if I take a nose dive or if these heads live up to their billing. Are your numbers on that build tru hull or out the prop? I'd be happy with that also. I'd think the sx drive would be safe with engine maxing out at 52 to 5400 rpm.

Is wet trq and wet power out the stock exhaust and leg? Are trick wedge flo numbers comparable or better than vortec heads? I like your numbers headers or not.

Are talking about fuel injection instead of carb? If so I'm not opposed to that un-less it's considerable more expense. I have heard that efi is a lot of the reason rings and cylinders don't get washed out and wore out near as fast as back when everything had carbs. I ran a flying toilet with methanol in my 70 Cuda with 440. The fear was instant the first time I fired it up but I got past that. The acceleration was instant also. Better than any carb I had used up to that time. I do understand it was manual and not efi but I was able to better understand and accept efi as the future.

Mechanical and Electronic fuel injection has nothing to do with each other,,,,,other than fuel being added without airflow doing it.

True but both give you a feel of what fuel injection feels like as opposed to an old 4 barrel carter carb.

I thought about this and it would get me on the water lots faster. It's still a lot more power than the 305 that was in the boat. I've read the GLM's are copycats of the Kodiaks and I will make that improvement atleast for this year.

I looked at one more cam today. This would be running 1.6 rockers and with the GLM manifolds out the prop. Any opinion's on this Crower grind?


Chevrolet - 262, 267, 283, 302, 305, 307, 327, 350 & 400
Performance level - BeastINT/EXH - Dur @ .050” Lift: 214°/220° RR: 1.5/1.5 Gross Lift: .474”/.498” LSA: 114° RPM: 2100 to 4900 Redline: 5400


Chevrolet Hydraulic Roller Camshaft







Part Number
00401S

Engine Make
Chevrolet

Year
1957-1998

Part Class
Camshaft

Engine Class
Small Block

Camshaft Name
Original

Camshaft Series
Original

Engine Type
V8

Engine Size
262, 267, 283, 302, 305, 307, 327, 350 & 400

Product Type
Hydraulic Roller

Special note*
This cam has a smaller than stock base circle

Valve Lash
.000" intake and .000" exhaust

Lobe center
114

Advertised Duration: Intake / Exhaust
269 / 278

Duration @ .050" Lift: Intake / Exhaust
214 / 220

Lobe Lift: Intake / Exhaust
.316 / .332

Rocker Ratio: Intake / Exhaust
1.5 / 1.5

Rocker Ratio #2: Intake / Exhaust
1.6 / 1.6

Gross Valve Lift: Intake / Exhaust
.474 / .498

Gross Valve Lift #2: Intake / Exhaust
.507 / .531

CID
383

Low RPM
2200

Peak Torque
3400

Peak HP
4900

Redline
5400

CID #2
406

Low RPM #2
2100

Peak Torque #2
3300

Peak HP #2
4800

Redline #2
5300

Grind Number
208HR216

Recommended Kit #1
84544

Recommended Kit #2
84544LM

I run the 483LM EFI grind from Crower. It is a step up or two from the one you list but I don't run through the drive. I can't honestly give you an answer how it would behave exhausting out the prop but I am happy with the cam choice and product.

38 Special, you are not doing things 100% the way you wanted when you started this build, therefore you are getting yourself caught in erroneous thoughts.

Stop over thinking.

I would say a 212,218 at .050" on a 112LSA will be fine.

If you want to push it a little, a single pattern 218,218 at .050" with a 112LSA might just do it.

Going to A 114lsa cam in a small block makes it lazy. 112LSA is bad enough, but what we are forced to in the marine world. Outside of boats, we would be 108 or under...mostly under. Just sayin.

Go get a cam and finish the build. Liquid water is coming soon.

I agree with SB. A 212/218 even with a 110 would probably be fine. Ran a comp 260H 212/212 110 with stock exh on the org 5.7, no problems. I'd go the 212/218 hyd roller comp and be done with it.

I am so far removed from where or what I started out with. Lol Now I'm sick of looking at cams I can't hardly take anymore. I had made up my mind on this one today until I had seen you guy's new post. Tell me more about the single pattern 218,218 @.050 with 112LSA. Can it be had in hyd roller and what kind of lift? Is it a bit more aggressive?

Lunati 20080720 (Formerly Part Number 60120) Chevrolet Small Block LT1, LT4, & 1987-Present Hydraulic Roller Voodoo Camshaft RPM Range 1600 - 5600 Lift .507"/.515" [email protected] 211/219 LSA/IAC 112/106
Excellent choice for stock to mildly modified engines, works well with OEM style injection, great inboard/outboard marine cam for economy and sking. Good mileage and torque increase.



RPM Range: 1600 - 5600
Lift with 1.6 Rocker: .507"/.515"
Duration @ .050": 211/219
Advertised Duration: 262/270
LSA/IAC: 112/106
Valve Lash: Hyd/Hyd


Correct me if I am wrong but it looks close to your first recommendation above.

I am listening. How would you compare the 212/218 you mention to the last cam above I post specs on? I read today comps share much of the same design of the lanuti voodoo series.

This was the idea for the start of my build and then I ran across the Kellogg stroker crank. Of course I didn't know or even think about headers or a good exhaust when I got it in a boat. 444 ft lb and 470 H.P. from a 350 with the EQ heads and the 108 LSA cam.

http://www.popularhotrodding.com/tec...d/viewall.html

Just got my 383 and putting it in my powerplay integra

Used the Howards HRS110245-12
225/231
112

Heres my dyno numbers...
http://i1057.photobucket.com/albums/...312_091026.jpg

Those are the numbers I expected to see when I got done with mine but that was back in the take home a couple of grand a week days. Lol Now it's take home $1,700 every 80 straight + 30 hours more time and a half and the overtime has leaned out a lot so needless to say it has changed the complexion of my build. It's all good, at least I'm working and I am still going to enjoy a 383 in a light boat which is a step up from the 140 mercruiser tri hull that was my first boat.