Hey folks,

I have purchased the sum-8810 cam with my beloved ls firing order for my rebuilt 10:1 sbc 305.
This cam is far to radical for this engine an my plans.
So I sent it to an cam expert and they told me unfortunately they can not regrind that cam to make it tamer.

Here is the problem, I can't send the cam back to summit. Either I have to sell it or I have to use it now.
Question for "use it":

Is it possible that it can be street driven, if I use Rhoads V-Max Lifters with them to restore some of the vacuum I will loose with that amount of overlap (17° @ .050")
If I dont install it at 3° advanced but 6° instead, and in combination with the Rhoads lifters, do you guys think Im able to drive this cam on the street?

Greetings,

Chris

 

That cam will drive just fine on the streets as is.
.




 

NEVER band-aid a poor cam choice. Buy the correct cam.
You are going to spend way more money on the other valvetrain parts to go with this wrong cam than buying the right cam to begin with.

 

This is correct.

THIMK how a cam works: "lift" is THE DIFFERENCE BETWEEN the "tip" of the lobe, and the "heel". The tip is virtually always the same height, from bone-stock to seriously wild, up until you have to get into reduced base circle designs for strokers and whatnot; basically, it's as big as the lobe can be, and it still slide through the bearings. The way a cam is made "bigger" is by grinding material off of the heel. To make one "smaller" you'd have to add material to the heel. Clearly not a realistic real-world option. And even if it COULD be done, regrinding a cam usually costs AT LEAST half of just buying another, and therefore isn't usually financially commonsensical for a $300 cam.

232/242° in a 305 is gonna act more like about a 236/250° would in a 350. A cam with that much intake duration is gonna want AT LEAST a 3000 RPM converter in a 350, and preferably more like 3500; it'll want even more in a 305. It'll be pretty damn rowdy. 10:1 compression isn't nearly enough for it in such a small motor N/A. After all, there's no such thing as "too much cam"; there's only "not enough motor", and that's where it'll put you. Which is not the same as "can't drive it on the street"; only, it'll have poor low-speed manners, very soggy "leave" without ALOT of gear and/or converter, and very poor gas mileage. Since you tell us nothing about what vehicle it's going in, what it weighs, the drive train or what type of transmission even, what heads it has, and above all what it'll actually be used for (only a hint that it may be on the street at least part-time), it's hard to say whether it'll work tolerably enough for you. I'm not seeing how it will be anywhere close to "optimum" in any case.

The firing order is irrelevant to all of this. Of all the things I can see to get wound up over, that's somewhere below the bottom of the list.

I would NOT use the Rhoads lifters in anything I build. Back decades ago when I was building lots of motors for people, and those were new on the market, somebody had me install them in their motor. They then paid me to take them out and put normal ones in about 2 months later. Other people may feel differently about using them; after all, it's a matter of "opinion", and perceived suitability for an intended purpose, not some kind of "fact"; butt what "fact" there is, remains, and that is, they don't generally live up to their hype for most people. Sure, some people are satisfied, butt FAR MORE are not.

Advancing a cam is another "crutch" for a mismatched cam selection. Don't forget, doing that changes the P-V clearance. Specifically, it moves the intake valve closer to the piston near TDC (will be at its worst just after TDC). With that much lift and intake duration (duration is FAR MORE important to this matter than peak lift), that could be a serious issue; it would CERTAINLY require checking. Not something I would just "do" on a lark. Additionally, if that one is like most of their cams of that general sort, it's already somewhat advanced from the stock intake lobe center, such that its ICL is already at like 104° or 106° instead of the usual 108°, meaning you already don't have as much room to dink with that before things start crashing into each other.

Sell it and buy the right cam for whatever you're doing. Don't shoot yourself in the shorts over having made one mistake, by compounding it. https://en.wikipedia.org/wiki/Sunk_cost

 

Thanks all for your advice.
I will sell it then or safe it for later days.

@sofakingdom : Why did they want you to put the rhoads lifters back out the engine?

 

They were noisy, unpredictable, and temperature-sensitive. Plus, they didn't really seem to make much difference to the cam behavior in the first place, as they found out afterwards.

 

Good 383 cam. Not a 305 cam