I am going to be boring my 350 and its oing to be a 355 soon, i am wondering what size cam would give me good hp. I have vortec heads on it and the valve guides are going to be cute to accept a larger lift cam,will have good shorty headers, exhaust,a 2500 stall converter, with a 3.23 rear, edelbrock performer vortec RPM intake manifold, with a HOlley DP carb. It has a XE262 Comp cams camshaft in it now. i want enough power to beat a stock LS1 6spd. ANy ideas? I'm looking at this lunati camshaft.....

http://store.summitracing.com/partde...w=1&N=700+150+

What do you think? Or is that too big? i was told lunati Voodoo camshafts are good.
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the only other thing i was looking at is the operating range, 2,200-6,400 seems a little high.....

 

save your money and put some 1.6 rockers on that cam

 

I want to put some 1.6 rockers on in addition to the new cam.

 

You need more gear. The cam is ok and you can use the converter you have with it. I would go bigger cam if I were you.

 

Bigger than the lunati that i showed? I want the car to be street able and not lope a ton. Somewhat tame would be nice.

 

I drive my car on the street alot never had a problem yet. I have this cam
http://store.summitracing.com/partde...2&autoview=sku

Im not saying go that big. But a little bigger wouldnt hurt.

 

Is your engine a flat tappet cam engine?

 

Yes it is. Hydraulic flat tappet.

 

JUst wondering. I was looking under your avatar and thought maybe you selected a flat tappet on accident.

 

all these big cams on the street are retarded

you dont need it

it is a waste of money and effort

unless you pull up next to a mustang and you are 16 yrs old

 

Rather than complain give me advice i don't care for ppl who just post to complain, do you have helpful advice of not? if not then stop talking. I can run whatever i want in my car and on the street and track.

 

The combo is fairly similar to mine (though I use a 4spd manual) and same gear I had last year... the XE268 or XE274 would be a good choice for that engine, if you get the compression up between 10.0-10.5:1. Both are still pretty street friendly cams, sound really nice, and make lots of power. I drove mine all year round with the XE274 and it did just fine in even the -50* weather. I like that cam.

 

So a big cam that makes lots of power in a properly supported platform is a waste of money and effort? How do you know what someone needs? Maybe they prefer more HP than you do?

 

Summit does not have the XE274 on their site, they only have the XE268, and you guys do know its a hydraulic flat tappet right?

 

Nevermind i found the XE274 in a set with the lifters. for $179.95. How much more power will that bring me than the XE262 i'm running? also what kind of lope would a cam this size have?

 

Also another thing, why are the lunati camshafts so much cheaper than comp cams camshafts? any real reason or no? maybe just cheaper metals? idk anyone know?

 

It will bring a very noticeable difference... its quite a bit larger cam. It will have somewhat of a choppy idle, but not violently rough sounding, and make noticeably more midrange and top end power. You'll be pretty happy with the difference IMO.

 

From the different things I've done with my car, it seems pretty fair to say every 5 degrees of intake duration should be worth a tenth in the 1/4. My guess is the cam you're looking at should get you .25-.3 in the 1/4. I only see the 1.6 rockers helping power too, but that I don't have a number to put to. It probably will make peak power around the 6000rpm area, so ideally it will rev to about 6500rpm for a fast pass on the strip.

 

Some people are still proponents of the RV cam I guess. Nothing wrong with it, we just choose to go faster.

 

The XE274 and some 3.73's and that would be a pretty fast street car. I think you would be happy. You might need to throw a higher stall converter in there.

 

the cam you posted would be alright, but personally i would go a bit bigger on lift since you are machining the guides anyways.

defenitly figure the cam first, then get a convetor. the two go hand n hand. if you have more duration/lift the cam will not stall a tight convertor, rendering it useless with your combo. build the engine then call art carr or hughes with your specs and they will guide you from there. ive heard ******* convetors is good to, and cheap.

 

anyone can chime in on this..... is it worth it to go out and bore the motor to a 355 and add flat top pistons to raise compression?.... is it worth it? will i really have THAT MUCH more compression than my 350 with dish pistons? Thanks

 

more compression means more power, those head u have are 72cc prolly, and they flow pretty good, that will compliment a good cam quite well. so yes i think it is "worth it"

 

The heads are vortecs they are 64 cc.....

 

It is never worth it to bore an engine that does not need it. Boring is simply a method of repairing cylinders that are out of spec. If the cylinder does not exhibit excessive taper or out of round, and the bore is within spec, you can use a ball hone to break the glaze and go with standard pistons, with a different compression ratio.

It is also noteworthy to add that some people feel that if you are installing pistons they should be balanced with the assembly and every bore bored exact for the pistons, hence the need to go to .030 over when installing new pistons. For a street driven car that sees some track time, this is not necessary.

 

350
Vortec heads
XR276HR w/ 1.6 rockers (224/230 .532"/.540")
RPM Air Gap and 670 Holley
LT headers w/single 3" no cat back
700R4 w/ Street Fighter converter (+/- 3000 stall)
3.70 gear
26" (old) drag radials
3650 lbs
12.9 @ 106 w/ 1.90 60'
Is that as fast as an LS1 6 speed? Probably not although I figure I can find 2/10's in the 60' with slicks and then maybe 12.5's.

 

but how often due you find a standard bore 350 thats just honable? .30 over isnt the end of the line for a sbc. we are talking around 75,000 miles at least for a mild well built street/strip engine, how often is it going to be rebuilt.

and why the hell is R E D neck bleeped out!! seriously! red neck??????

 

Generally speaking, if you can get ahold of an engine with less than 30K on it, you stand a really good chance. For a long time people were all about those 260hp work van replacement engines in cars. I cant count how many my brother and I got for a song when someone realized it was dog *** slow. Lots of times 200 bucks or so and we would have a longblock when they yanked it. Trash the heads, give it a quick hone in the garage with the makita drill, a dingleberry hone, and some atf. Clean it all out and use some good flat tops. We never rebalanced, most of the time used the same cam bearings. Budget hot rodding, and they would run.

 

well damn, u wana throw one of the engines my way!! sh*t yea, i cant argue that, no money in machine work with 30k and quik turn around!! but then again, not everyone can get a hold of engines of that stature.

 

MY engine has about 75,000 miles on it so i can't just hone and install new pistons?

 

imo i would say no, thats your call, i was refering to a bored and rebuild engine lasting 75k. pull the heads and look for a ridge at the top of the bore.

 

It depends man. I have seen sbc's with that many miles with no ring ridge at all. Could even still make out crosshatchings on the cylinder walls. If yourse comes out in good shape, maybe. You really need to invest in a dial bore gauge. You can get a cheap one that will do the job just fine. If the taper and out of round is within spec, and there isnt appreciable cylinder wear, go for it. Word to the wise though, if there is any ridge at the top of the cylinder, no. I know lots of people think that is what a ridge reamer is for, it isnt. A ridge reamer is there to clean the bore up enough to drive the piston back out of the block for disassembly. You cant cut the ridge and hone it and go. Its all up to the individual engine. DO you have it apart yet? Take some pics and post them up. I will get you a link to a cheap dial bore gauge if you like. Just let me know.

 

i guess what i'm still asking is the power gains really worth it to bore the motor? I'm on a tight budget so i'm saving pennies where ever i can lol but if its worth it i'll do it. I'm keeping the same crank and connecting rods just replacing the pistons. so in your honest opinion are the gains from boring worth it for $200-350 bucks?

 

Are you doing anything to the bottom end of the motor? 5500rpm or so is the upper limit for stock rod bolts to see on a regular basis, above that you're starting to gamble. If you're gonna go with 220 degree's or more of duration at .050" you're gonna need to be running up to 6000+ rpm to build your power, and if you want to do that regularly and reliably, you probably should at least think about some ARP hardware. Also, as previously mentioned, if you want to go cam, you're gonna want better gears to capitalize on that, especially behind the extremely wide ratio's of the 700R4.

 

can you put a link from maybe summit if they have the hardware?.... I've never looked that stuff up)

 

This is some mandatory reading regarding rod bolts - https://www.thirdgen.org/forums/tech...d+bottom+stock

Here is an example of what you'd be looking for from summit, you'd want to verify things are right for your particular application.

http://store.summitracing.com/partde...3&autoview=sku

 

Yes and no. How long do you want this engine to last, and what are the realistic power goals? If you are really looking to go 6K as your upper shift point I would recommend better rod bolts, as posted above. You will need to get your rods resized to have them installed, usually about 80 bucks. The only real way to know if you need to have it bored is to measure the bore though. We can guess one way or the other, but it will not be the right answer until we can verify the condition of the bore.

 

If it doesn't NEED a bore, don't bore it.

 

if it doesn't need a bore than could i install flat tops instead of the dish pistons in it now? or is that a no based on the same rule as changing lifters?

 

Sure you can. If the cylinders are in spec(once again, we are back at measuring them, instead of speculating) you can certainly run a different set of pistons, we do it all the time. You can change flat tappet lifters too. Its OK to run new lifters on an old cam, as long as you follow proper break in procedures as if its a new cam. You just cant mix old lifters.

 

what do i use to measure the bore?

 

Have you done any calculations regarding what static compression you would have with either type of piston? I haven't read anything about what you have already.
How about dynamic compression and the kind of cam you intend to get?
As has been stated already, if it dosen't need to be bored then don't do it.
There may be a power gain if the compression calculations show that the static c.r. is too low with respect to the cam you'll run and new pistons may be required to achieve it. There are alternatives to raising the c.r. as well.
And my two cents says ARP rod bolts are a must.

 

Typically with a bore gauge. (pictured)
You can also use snap gauges and a micrometer.

 

If i calculated right.... right now i have about 9.01 static compression with the dish pistons with 4 valve reliefs and about 9.50 with flat tops with 2 valve reliefs. ( approx.)

 

http://cgi.ebay.com/2-6-BEST-CYLINDE...3A1%7C294%3A50

That is a link to the exact one that I own. Its not the best on the market, but it does the job, and well. I use it on customers engines all the time. You will find that no matter the cost, a fine measurement tool is only as accurate as the person using it.

 

I use the same ones. A bore gauge is a relatively simple thing, the only precision part is the dial indicator, and you have to calibrate it with a micrometer anyway.

 

I run a 350 std bore block with a stock deck height of .025" in the hole.
Vortec 64cc heads (assumed, not measured)
Speed Pro flat top pistons with 6cc valve reliefs
Victor Reinz .026" head gasket
Static CR of 9.97:1
Combined with my XR276 HR cam I end up with a dynamic CR of 8.25:1.
My experience is that for my application that's about as much CR as I dare to run. Always use 94 octane and keep my engine temps around 190f.
Although the power gains are minimal with slightly higher compression all the increments add up eventually and it might make the difference in achieving your et objective. Mine was to go 12's all day and knock down 20+mpg on the highway.

 

is the is XE274 cam?
http://store.summitracing.com/partde...&view=1&N=700+
So i have the have the rod bolt holes resized to fit the ARP bolts? And a machine shop has to do it?

 

They have to resize the big end of the rod to do that.

 

It's a machine shop operation. Around 80 bucks a set plus the cost of the bolts.
That's cheap piece of mind. My build is at least 60 thousand miles old and I bounce off the 6500rpm limiter all the time (with a cast crank which is something I don't advise).