Hi Guys.. you all were simply fantastic when I asked about the 305 I have vs a 350. Simply wonderful. I know several of you said go with a slightly large cam, etc. SO as you all found out. I'm no motor mechanic. I found a place to download (for free) a "Professional Cam selection" software It's at Compcams.com. Anyway. I went and downloaded it and so OF COURSE that just prompted more questions. It asks you to make choices for how the motor is (or will be ) built.... What kind of lifters it has: Solid, hydraulic, solid-roller, hydraulic-roller. I got no clue. Then of course the only ones that give me any options would be hydraulic or (forgot the other one)... anyway They have the cam only (which some are areound $300)... and they also show the whole kits. Most say "stock springs can NOT be used" Some KITS are $300, and go all the way up to over $900. All very interesting. Tells you the valve lash, duration, lift angle, etc. I guess if I knew what KIND of lifters it has that would be a start. For a couple it list NO options at all. Then of course the software asks for what type heads I got... (for example: domestic 2 valve / low perf / stock ports) Well Chevy is domestic. I figure mine is two valves (an intake and an exhaust valve) but I also know I got the HO package with my 305, so it's not really a "low perf". I see an option that says HP> I guess maybe that means High perf. It also asked for Manifold type and then total airflow induction... go figure. Not sure with all this being thrown at ya.. I should even expect an answer... LOL It's a lot to fathom for someone who can't quite comprehend it all. Maybe for someone who understands all this it is quite easy..?? We'll see if anyone throws in their 2 cents worth..
when you say "kit" it could mean a lot of different things. whether you want hydraulic or solid lifters depends on what you are doing. does the kit include lifters, cam bearings, timing set. there are some many options for cams in sbc's nowadays it would help to know what your plans for the motor.
Yeah. the kits look like they come with all the SAME things. Thats what make me so cnfused about such wide prices. Anyway the kits look like the come with: Cam, timing chain, and the 'gears' it runs on, push rods, valve springs and locking caps, ... oh heck.. all this... lol http://www.compperformancegroupstores.com/store/graphics/00000001/08-000-08K_600.jpg
i missed your first post..how do you plan on using this engine? the link shows a picture of a hydraulic roller cam , is that what you want?
yeah.. we had a big long discussion about the motors... about 4 pages worth. Thats why i was braggin on everyone for jumping in and helping me... I'll try to get everyone up to speed. This is a 305 SB. I am going to get it rebuilt in the next few weeks. It is going in a '46 Studebaker street rod pickup. I am building this pretty much as a 'daily driver' as I plan to drive it al LOT. I WANT it to get 20+ MPG when I am done. The more the better. Now the motor I am starting with is a High Output 305. Come out of a 1986 Camero of the like sports car. Has the markings of the HO block and 601 HO heads. On the other thread folks said this motor came with a slightly hotter cam. Some folks said to use a 268?? then some said that make be a little big. Just for refference here is the link to the "old" thread so you can read up if you want to... http://www.jalopyjournal.com/forum/showthread.php?t=277330&highlight=305+vs+350 SO thats kinda what prompted this whole discussion I suppose. Some said use the 268... some said not... so I was trying to educate myself and do some research on my own. All I accomplished was confusing myself (thats nothing new) SO then I saw > you MSUt buy this and That if you put in a new cam,.. and saw a (almost) $600 difference in the cam kits... figured you folks here would know why all the discrepencys.
OH.. as far as how I plan on using it... It's gonna be driven... interstate,.. around town, etc... Putting in a 700R4 ******,.. and plan on putting in rear end gears that'll turn about 200 rpm at 75 mph
myself id put a stock cam and lifter set and timing chain in it and call it reliable, a two barrel would give you milage too,ok let the flaming begin
Since the block will need to be torn apart, cleaned, and machine work performed (bore, hone, crank turned, etc) you will get to know your local machine shop. Machine shops know a lot about engines, especially chevy v-8's. For your demands, you just need a stock rebuild. The cheapest route to go, is to buy a kit that includes hydraulic lifters and springs. Let your machine shop make the selection. Comp Cams is a good company, but for a stock motor, you could do well with anyone. Generally speaking, you want a hydraulic roller cam, and not a flat tappet cam. The reason is, the off-t******lf oil no longer contains all the nutriants a flat tappet camshaft needs (i.e., zinc).
200 Rpm's at 75? I think you forgot a zero. Anyways, sence you aren't making a screamer forget the 268, and go with the 260 or 255. As far as your heads etcetra, I THINK the max lift on a stock 305 head is about .460" give or take, without having machine work done. I'm running a 268 in my 350 with 305 heads and it works well enough with the stock springs etcetra. But anymore lift is getting into the twilight zone without having the guides shortened. I don't know how much you are planning on spending but you can go with a hydrolic cam a lot cheaper than a roller set up. Buy the cam only from somplace like Summit, and get the rest of the stuff locally, as long as it isn't made in the 3rd world. Not too long ago I put together a "gas sipper" 305. This has a Comp high energy 255 degree cam, mildly ported large chamber 305 4 barrel heads, and .030 over flat topped pistons. I haven't installed it yet so I can't say just how well it will do. Anyway pick a cam that will match up with your cruise rpm range. Good Luck!
ok.. lets see when do I start... 4 barrel... gonna go that route. Sat down talked to several motor guys and they all said 4 barrel will be cheaper on fuel than a two barrel. I got a holley, needs to be rebuilt. I can afford it. I paid $5 for it.. LOL (no didn't leave a zero off 'that' time... LOL Machine shop.. yeah.. good guys. They have already rebuilt 4 motor for my dad. o a good job all the way around. Very dependable and cheap. SO cheap I'm gonna drive 400 miles to take it to them. Max I hear what you are saying about the zinc. I'll remember that. Good info. I had planned on running synthetic oil in this motor all the time after I get it rebuilt. Someone mentioned pistons. These I have are the old flat top style. TOTALLY flat still. Got two teeny tiny eye browes for the clearance of the valves I suppose. Depth is no thicker than the thickness of a dime and maybe 1/3 the cir***ference. Looks like a little upside down smiley face. I'm not sold on any "name brand stuff"... I know often you pay extra for stuff and thats all you get... call it the name,.. and something else would of been JUST as good at 1/3 the price. Good idea... anyway of knowing what that is... or should my motor guy automatically know..?? Any formula that tells me that..?? I think I can ***ume 268 is too big,.. and common sense (by some of you) would know what is "automatically" too small.
My 2 cents worth..... For $300, that better be a roller cam. Otherwise use anybody's "RV cam" for $85. Dead serious, in the online catalog if there's not a winnebago driving out of the header graphics on the page you're using, turn the page til you find it. Anybody means TRW, Wolverine, etc. The cam you seek uses stock springs without complaint, it's under 420 valve lift and under 200 duration. Yes, you can go all kinds of crazy trying to outsmart the 305. At the end of the day it still shrouds the valves and undoes all your thinking and spending. Get a cheap, small, hydraulic old-school cam. Like the old saying, K.I.S.S. Good luck
Shifty is right. You want a cam in the low 400's lift, low duration. I might go a little higher on the duration, but like he said you don't need anything fancy. Here is a good cam for you, I use these summit cams all the time with no issues, and they are cheap. http://store.summitracing.com/partdetail.asp?part=SUM%2D1101&autoview=sku
I switched out the 4 barrel on my 85 C/10 with a 305 for a 60's 2 barrel off a 327 (intake and all). The truck now gets about 23mpg, and it didn't loose much power at all. Thats in a big ugly full-size chevy with a 4spd manual and no over drive.
another reason (and why oem stuff has roller cam nowadays) is less internal friction. mo power available and better milage. might not be a bunch but....
Concur on the friction. Read before building a flat tappet engine: http://www.compcams.com/Base/pdf/FlatTappetCamTechBulletin.pdf Not to scare anyone away, as I run a flat tappet in my hemi (only cam available), it's just that I have to be selective in my oil (I use Gibbs) as I need the added zinc to keep the lobes hardened. Comp Cams sells some really streetable cams that are called Retro-Fit hydraulic roller camshafts. So if your engine started out as a flat tappet, this kit should take you into the 21st century.
what i'd like to know is how MUCH the roller lifters help? apples to apples, ya know? same cam specs,springs etc.... anybody know?
old hot rod articles kinda unsure on hp gain because of the rollers profile will be different, the best part is the reliability of the roller. i have ones that have run in a lot of differant engines and still are in good shape.
a cam that would work for this would prob. be the old mtc1 melling ,duration around 204 @ 050 int and 214 @ 050 ex around 420 int and 440 ex. works pretty good in a 305.
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