I'm needing a cam by friday. which one???

[Guest Anonymous]

Hi Guys and HAPPY NEW YEAR,

I'm needing to buy a cam for my 350 engine.

 

1.it's a 350 motor stock 4-bolt main

2.stock 70cc camber heads

3.edelbrock 2101 intake

4.holley 650 D/P carb

5.block hugger headers

6.unlite dist

7.havn't got the T/converter yet?

8.700R4 tranny

9.R-200 3:90 "open" diff.

if you guys know what cam & T/converter I should buy,I'll buy it on friday.....Thanks

[Guest Anonymous]

Your intake is a "Performer" and Edelbrock recomends a 204 Degree intake /214 degree exhaust duration at .050" Lift.420"intake/.442"exhaust with an under 750 CFM carburator. You could bump up to a 214/224 degree cam but with your heads manifold and carb not much more than this.You are probably looking at 250 to 300 HP. Summit sells their own brand what I suspect are Edelbrock cams and lifters for about $50.00 less or about $80.00.Summit also sells waht I suspect is a TCI converter for stock and mildly hopped for around $230.00 with a 1500-1900rpm stall. Together this purchase should net you about 10 % discount. This should give you a very streetable tire smoker with about 20 miles to the gallon. I am not a big fan of after market stall torque converters

[Guest Anonymous]

Thanks for the info.

I'll look into this set-up

and take everything you said

into consideration

Thanks again....

[Guest Anonymous]

40 V8.. wait awhile for more suggestions..someone may have a better cam "hop-up" opinion than mine. I like your set-up for a wash and wear street driver.

[Hitman47]

Well what HP are you looking for? and torque? I would go with a crane xe 240 its fairly cheap with in sane hp

 

Chad

[DavyZ]

Tomahawk nailed exactly what I was going to advise you to do. I have roughly the smae engine as you do, but I have a Weiand Stealth manifold and I went with the 214/224 Summit cam (K-1103). The hp combo is higher then 300 HP BTW if your heads are aftermarket and the compression is 9:1 or greater. Just food for thought.

 

Davy

[z ya]

I would run a little more cam if I were you. I would suggest Comp Cams 268 High Energy. It a great cam with good all around power in the 1500 to 5500 rpm range. Perfect for you set up. As for a converter recomendation ,I would suggest a TCI Saturday Nite special. Its stall rating is 2000 rpm . I have used both of these together and had great results! Good luck with your build up.

[Mike C]

The Comp 268 is the biggest you will want to go with the compression you have. The Comp 260 is probably a better choice, but for my money, I would run the Crane Energizer 266 instead of the Comp 260 or the Crane 272 instead of the Comp 268. For max effort motors, I really like Comp products, but for a daily driver, mild cam, you can't beat the Energizer series where you can buy cam and lifters for $100, just the price of the Comp cam alone.

[z ya]

My old combo :

 

350

9 to 1 comp

268/454 comp cam

performer intake

performer 600 carb

1 5/8 long tubes

mallory unilite

2.5 dual exhaust

TH400 with Sat night special converter

 

This set up was on my daily driver and it performed extremly well and was very reliable!

[grumpyvette]

Ok I get lots of questions on how to build a good street engine and how to find and match the correct parts, now Im going to be refering to your average hot street combos built on a budget with easily available parts.

 

first the math

(1)youll be limited to about 1.2 hp per cid on engine size

(2) YOULL BE LIMITER to about 6400rpm with HYDROLIC flat tappet cams and about 7500rpm with SOLID LIFTER flat tappet cams

(3)piston speeds that exceed 4000fpm usually lead to trouble

(4)dynamic compression ratios of over about 8.3:1-8.5:1 with aluminum heads or about 7.8:1-8:1 with iron heads can cause detonation problems

(5)the formula for matching POTENTIAL HP to INTAKE PORT FLOW is (.257 x port flow at max cam lift x 8(3 of CYLINDERs)= POTENTIAL hp

(6) look closely at the duration used for each MATCHING rpm range. ALSO KEEP IN MIND THE DCR AND OVERLAP MUST MATCH look here these are the valve timeing overlap ranges that are most likely to work correctly trucks/good mileage towing 10-35 degs overlap daily driven low rpm performance 30-55degs overlap hot street performance 50-75 degs overlap oval track racing 70-95degs overlap dragster/comp eliminator engines 90-115 degs overlap but all engines will need the correct matching dcr for those overlap figures to correctly scavage the cylinders in the rpm ranges that apply to each engines use range

 

OK now lets follow the rules and build an engine suitable for the average street strip car and lets set the goals at pushing a 3400 lb car to 12.5 seconds in the 1/4 mile with a 3.08 rear gear, and TH350 (JUST TO SCREW THINGS UP BECAUSE USEING A 4.11 RATIO MAKES THINGS TO EASY) 26.5" tires and an auto transmission to simulate an average late 70s car.

well the first thing we are going to need to know is how much hp /tq will we need useing this quick guide

 

http://www.prestage.com/carmath/calc_ETMPH.asp

 

we find that we need about 375 rear wheel hp or 469 flywheel hp to easily run very low 12s

those 3.08 rear gears and 26.5" tires we will only be spinning about 4900rpm in the lights so well need an engine with lots of mid range tq, the 469 flywheel hp says we will require heads that flow at least about 230-240 cfm at about .48-.499 lift if we figure that we must build a hydrolic cammed torque monster that has very high intake port speeds for good volumetric efficiency in the mid rpm ranges to get the tq curve correct for those crappy 3.08 rear gears, the cam rpm chart shows we will need a cam in the 230@.050 duration range with about a 50-75 degree overlap and we need about 390-406 cid mimimum to get 469hp, REMEMBER WE ARE ONLY SPINNING 4900rpm in the lights so an engine that makes most of its hp at far higher rpms is a waste, that combined with the low rpm range would make a 383-406 the first choices here.

http://www.prestage.com/carmath/calc_gears.asp

 

so what we wind up with is a 406 with a 10.5:1 static compression, a comp cams #12-246-3 cam with 190cc AFR heads as the smallest port heads that flow enough air at that low duration http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-246-3

open headers 1 5/8" full length,at the track, an 850 carb and a dual plane intake. a 3000rpm stall speed, shifts at about 5500rpm

 

now theres other combos and ways of getting there but you get the idea about how the parts should all be working towards the goal and within the restrictions , drop a cam like the crane cams #114681 and your hp goes up but above the rpm range that you ideally need it in altho the results are still good, a 3.73-4.11 rear gear would make the change to the solid lifter crane cam a far better choice

 

 

now lets look at your combo, to keep the most torque (and keep in mind your parts are designed for torque not high rpms) youll need to keep the duration fairly low. because youve got about 9:1 compression and a cam with more than about 215 degs@ .050 will have a low torque curve untill the rpms pick up to about 3000rpm, most of your parts are designed for low to mid range torque also , an OPEN 3.90 rear will not allow you to put to much power to the ground either. this cam and a 2000rpm stall match well but will limit your rpms to about 5200rpm

http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-234-2

 

but by going just one step larger like this cam below you will allow the engine to pull to about 5700 rpm and would be my choice because anything larger and the rest of your parts won,t support the rpm range anyway

http://www.compcams.com/information/search/CamDetails.asp?PartNumber=12-238-2

[Guest Anonymous]

DavyZ.. I have another SBC engine That I want to run the Summit 214/224 with Performer manifold and 600 CFM Edelbrock,block huggers. I have the 204/214 in my Tomahawk project. I feel that these combinations may not win many races but worth a lot good of trouble free and streetable service that will not tax the oem parts.