SBC Vortec Cam Recommendations!
 

Hello all! This is my first writing. Seems to be an excellent board, with even better members. I have purchased Dennis M's book and gone through it several times. I currently have a 1983 17' Formula powered by a 4.3L GM/Merc V6 with factory 4 barrel QJ and 4" risers.. I think this is the smallest boat on the board, hence my log-in name. Runs excellent, and goes a needle over 50mph when fuel is less than 1/4 tank (weight). The engine is getting tired (smoke, oil pressure, rust, etc) and I have acquired a GM 350 Vortec (roller cam). I am wondering the best cam to use without changing all ther head stuff like springs, spring seats, retaingers, and valve seals. I think the Vortec heads (906's and 062's) are limited to about 0.480, and I would like the best top end performance, not worried about idle quality or low end. Most cams get pretty high lift numbers when the duration is anything greater than stock. I have an RPM air gap, electric fuel pump, and 750 Edelbrock carb to go with it all. I will also install through transom exhaust with this set up. The outdrive ratio is V6, I think 1.64 or something close. I don't think this motor was original in this boat. I see all others with 4 cylinders in them, and the speed of the boat is impressive, even with a V6. They call it a Formula 1. Dennis's bok is great, but stops shy of Vortec recommendations. Any words are appreciated, including thought on the boat. Thanks.

Clint ([email protected])

ps - Absolut-Tile, who is the current owner of your old Formula 242? I am still looking to buy a F-242 with twin 350's, or F-272 w/T-330/454's. Hope your 31' Formula with surface drives is working well for you (including electrical) Thanks.

Sounds like you have all you need. Here is the cam I chose for my non vortec I'm putting together. It's a non roller though.Cam

I don't know who bought my 242, I sold it on consignment.

The 302 is running well, but for the transmission lines I'm replacing.

Here is a picture of a 350 I'm putting together for my Donzi Minx.

you're right about the cam limits on the Vortec motors......you can actually scqueeze a little higher out of it if you went with the corvette oil seals on the valves....they are smaller and would allow the valve to open more without crushing them but not much. Theres also machining for higher lift which at that point you may opt for some port work and you start getting close to just buying a used set of performace heads. Its a wicked circle aint it! :D

The 6.2 has a 214/220 and has .452/.465. This is supposed to be a good cam in the 350.

6.2 Cam
 

sounds a lot like the crane 2032 roller...

It is the same profile as the Crane #104224:) Dwight

Thanks !!!
 

Excellent. I will do my homework on these cams! Also saw a Holley marine catalog pushing their Lunati cams. Have not seen much written about them here. Seems like Crane and Comp are by far the most popular. Thank you again for all of your input. This motor is going into a 17' Formula, so I hope it will move quite well.

Calling Wally - Corvette Seals Vortec Heads
 

Hello all. Excellent cam information. Wally, your statement of using Corvette oil selas on Vortec iron heads to shorten the total seal height makes great sense, and is the first I have heard of it. Would you or anybody else know what the part number for these seals are? If not the part number, would anybody know the year of Corvette which valve seals will fit the Vortec iron heads (062's)? I measured my lift clearance today and the retainer just kissed the valve oil seal at 0.480" with no spring. I used a dial indicator and magnetic base. If I can get a bit shorter seal, then I can run the next larger cam. If not, then the 6.2L Crane 2032 cam is sounding pretty good. Anybody know if stock Vortec springs are OK with the 6.2L cam? Maybe? Are the stock Vortec retainers strong enough for other springs? How about other retainers which may allow just a bit more travel before hitting the seals? I think they are out there, but don't know which ones. Sorry for the length. Thanks again for all the help!

SPP, I have the solution, I bought a guide cutter from comp cams and it cuts the top of the guide as well asthe diameter so you can then use .530 seals and also install a spring and retainer kit which is good to.600 from either crane or comp cams. At that point you can use whatever cam you want. I am going to do mine this afternoon so I will let you know how the cutting goes. On my 6.2 I am going to use a cam around 222/230 and around .509 to .530 with this set up. Dwight

when you guys gonna start running big cams :p :p


Whitey.. You'll like that cam, ran it in my first motor. Peaks out around 5250 rpm :)

Whitey - If it works well, let me know and I'd go have on the tool with you to use it, and you keep it when done. Let me know how it goes. Thanks. - Clint

Travis, That is good to hear about that cam. I now have one head done as far as the guide machining, I can now run a cam up to .550. What cam do would you use in my set up? Do you use the 1.6 rockers or are using the 1.5s? Oh and I am working myself up to the big cams;)

SPP I machined one head tonite and it is a easy process with the cutting tools. I have 2 sets of heads to do so I do not know how good the tools will hold up. I spent allllooottt of time checking and double checking and measuring. I figure I can use cam up to .550 but will use .500 as limit. The Crane spring kit is good to .600 so this looks like the route to go. Dwight

whitey.. i would use that crane roller 222/230 duration .509/.528 lift, ran it in my first vortec headed 383. It was a torque monster. I run 1.6 ratio rockers on intake and exhaust.

Travis

Travis what rocker ratio did you run on your older vortec engine? and what style rocker did you run? I have been thinking about sticking with the rail type but, I do not know if that is a good idea. Dwight

i had the heads machined for 7/16" screw in studs and guideplates. I didn't really wanna trust the "self aligning" rockers that these heads were made for. I ran the cran gold rockers 1.6 ratio on intake and exhuast. They are special ones from crane that are "narrow design" So the valve cover bolts fit between the roller rockers. If I had the money I would switch over to the T&D or jessel shaft rockers.

SmallPP, sorry i dont have any numbers for ya on the oil seals. You can actually from what i have read use the LT4 retainers and run up to a .488 lift cam on the stock vortecs with no mods. Ive been reading up on alot of vortec upgrades lately for my Yukon. Thinking of maybe making a 383 for it. But first need to get all my info straight before i jump into it :D

Thanks
 

Thank you everybody. If the guide cutter works well, let me know if you want 50% of the tool cost for me to borrow it for 1 day. Thanks again for all the words. I think I have to bolt the SBC short block in place, then assemble the heads and manifolds. I only have 22" deep (front-back) engine bay opening to put the engine in. It has to go in sideways and then rotate 90 and be bolted in and then built up. 17' Formula with built 350 should move OK I hope.

Let me see what kind of shape it is in once I have completed the first pair of heads. The head I have already done has turned out great. I spent alot of time measuring so at first it was a long process but by the last 2 guides I had a good system down. Dwight

Whitey - Did you look into Crane kit number 10309-1? It is supposed to be a drop in spring and retainer kit which allows almost 0.600" lift on a Vortec head with no head modifications (stock valve oil seal I guess). Any thoughts on this?

The spring is good for this and that is what I am going to use but, the retainer will hit the seal at about .480 lift. If you look at the foot notes on the site you will see what I mean. You do not have to change the spring seat just have to cut down the guide top to make the clearance for the retainer to seal.
Dwight

comp cams bee-hive/a done deal

SmallPP:
If you already have the heads off, then use some clay and check the intake and exhaust valve clearence to the piston before you install a cam with .480 lift or more, especially if you plan to use 1.6 rockers. Its a quick check and it could save you a lot of broken motors later. Valves don't get along well with piston tops and when you increase durations, they get closer without changing lift. Food for thought?
Raylar;)