camshaft for towing

[murre]

car chevy van g-20 ~5500Lbs and same times towing +4000Lbs
th700 lock up converter. gear 3,42:1
engine sbc 355" flatt top piston. heads 3923441 76cc with 1,94 and 1,6 valv. same bowl porting. CR maybe 8,5:1
have been thinking about these camshafts from summit. which is most suitable?

SUM-K1101
idle to 4500rpm
0,050 dur in 194 ex 204 lift 0,398 and 0,421
cam timing 0,050. intake open 10 atdc closes 24 abdc
exhuaust open 39 bbdc closes 15 btdc

SUM-K1102
1500 to 4800 rpm
0,050 dur in 204 ex 214 lift 0,421 and 0,444
cam timing 0,050. intake open 5 atdc closes 29 abdc
exhuaust open 44 bbdc closes 10 btdc

[mag2555]

This is a good time for the old old quote being " more valve lift makes more torque across the whole rpm band, and more duration makes more hp but at a higher rpm!"
Out of those two cam picks I would head for the second cam, but run it advanced 2 degrees and add higher ratio rockers with a correct new push rod lenght.
Do not forget to add new valve springs , keepers and valve seals while you are at it, and you need a seat pressure of no less than 115 psi.

[Keith Morganstein]

car chevy van g-20 ~5500Lbs and same times towing +4000Lbs
th700 lock up converter. gear 3,42:1
engine sbc 355" flatt top piston. heads 3923441 76cc with 1,94 and 1,6 valv. same bowl porting. CR maybe 8,5:1
have been thinking about these camshafts from summit. which is most suitable?

SUM-K1101
idle to 4500rpm
0,050 dur in 194 ex 204 lift 0,398 and 0,421
cam timing 0,050. intake open 10 atdc closes 24 abdc
exhuaust open 39 bbdc closes 15 btdc

SUM-K1102
1500 to 4800 rpm
0,050 dur in 204 ex 214 lift 0,421 and 0,444
cam timing 0,050. intake open 5 atdc closes 29 abdc
exhuaust open 44 bbdc closes 10 btdc

First cam is basically a stock replacement. Unless your cam is worn out, you wont notice a difference.

The second cam is the venerable old school melling MTC-1 "torque cam". It's not a bad choice, easy and gentle on the valve train. It will show some improvement for towing.

These "white box" generic cams are the least expensive you can buy. You can spend more and a get a more modern cam that will perform better.

[MT Jeff]

The first cam is just a stock 300hp 350 cam from back around 1970. Not really much different than what came out. That said of those two I would pick the second one with flat top pistons. What is your deck clearence? Get your quench below .050 if you can with different head gaskets to help with detonation. I would shoot for .040-.045, some hear would ga .035.

[MT Jeff]

What Keith said. Something like this http://www.summitracing.com/parts/lun-1 ... /chevrolet. I think UD Harold did these more recently. I have the next step up in my boat 355sbc and it performs very well. But it operates at a higher constant rpm.

[pdq67]

Imho, the great old .204/.214 "Performer cam" will do you nicely. ----- And don't go bigger than the old Crane 266/210 hi-cam

If you want SOTA, then the listed UDHarold cam OR Comp Cam's top of page "Pure Energy cam" will also be fine, although each at higher cost.

Add a complete new install kit with Z-28/-142 valve springs and go for trouble free operation.

If you want to get into your engine, then a valve job and new valve seals along with Fel-Pro's #1094, .015" thick steel shims to up your CR. a bit..

pdq67

PS., long dual WDT smooth perforated inner pipe glass packs with tailpipes out the rear will also help if you like their "Old-School" cackle that I dearly love!!

Otherwise, just install quieter "Turbo" type mufflers or such...

[RevTheory]

Isky 264 SuperCam would probably be my choice for a budget, shelf cam. Those 112 LSA cams always ran like lazy dogs, in my opinion. No real torque anywhere.

[MT Jeff]

OP, you never said if you have carb or efi. Also do you to pass emissions? It could make a difference in selection. Fartory efi won't tolerate too much deviation from stock without a different tune program.

[Walter R. Malik]

car chevy van g-20 ~5500Lbs and same times towing +4000Lbs
th700 lock up converter. gear 3,42:1
engine sbc 355" flatt top piston. heads 3923441 76cc with 1,94 and 1,6 valv. same bowl porting. CR maybe 8,5:1
have been thinking about these camshafts from summit. which is most suitable?

SUM-K1101
idle to 4500rpm
0,050 dur in 194 ex 204 lift 0,398 and 0,421
cam timing 0,050. intake open 10 atdc closes 24 abdc
exhuaust open 39 bbdc closes 15 btdc

SUM-K1102
1500 to 4800 rpm
0,050 dur in 204 ex 214 lift 0,421 and 0,444
cam timing 0,050. intake open 5 atdc closes 29 abdc
exhuaust open 44 bbdc closes 10 btdc

Forget about any power numbers observed at Wide Open Throttle and concentrate on the manners at part throttle operation and detonation resistance.

The single pattern Melling #22107 works exceptional for that type usage.

EDIT: 280 @ seat to seat - 208 @.050 - .272" lobe lift - .408" valve lift with 1.5/1 ratio rockers - 110 sep; 107 intake centerline.

[wyrmrider]

also what exhaust? headers? duals?
First I suggest new 1.6 rockers especially on the intakes
Second all those cams are very obsolete- You really do not think that Summit grinds cams?
for more obsolete cams at an even better price
http://catalog.elginind.com/download/PROSTOCK.PDF
scroll down to p 13
you can also check for rockers
find someone who is an Elgin distributor
That said you are much better off paying more and getting a modern grind, Bullet for example
AS Mike Jones said in another thread "there's a reason those cams are cheap" (however quality is good)
cost to distributors can be less than the cost of a billet to a camgrinder
here's Jones list, about as modern as you can get
http://jonescams.com/hydraulic-flat-tappet/
do your self a favor and at least fill out the form and post up any info you've left out back here
http://jonescams.com/street-performance/
add in trailer weight and tow speed/ rpm
gas mileage importance etc in the comments section

[dave brode]

Speaking of "summit" cams, here's a little cam listed for towing, 104* LSA;

http://www.summitracing.com/parts/sum-1100/overview/

There are many towing related threads here. Some have had very good results using 'small" tight LSA cams, but my take is, a tight LSA cam can be finicky, as far as exhaust pulse timing.

Dave

[CamKing]

Cam# SBCH, H65295-66299-111
260/264 Seat Duration
204/208 @ .050"
.295"/.299" Lobe Lift
.443"/.449" Valve Lift w/1.5 rockers
111 LSA
107 ICL

The better milage will pay for the difference in cost within a few thousand miles.

[murre]

thanks for the replies some more facts. I replace my 305 whit this 355. I'll pull my racing car with this. and will do some fishing trips with the car. I want it to be nice to drive and perhaps a little fuel-efficient.speed towing 50 mph not towing 62 mph.
engine are in pieces.heads are rebuilt with hardened valve seats for unleaded gas
carburator
exhaust not done yet.I'll use old stuff I have lying. maybe headers if they fit? mufflers will be 3" glass packs

I have bought all the parts except. camshaft, valve springs and Valve Spring Shims.
thinking about buying comp cams 980-16 valve springs.

I thought that one of the old camshafts would be nice to valve train
I live in Sweden so it is easiest to shop at summit racing.

[Keith Morganstein]

Mike Jones (camking) will have no problem shipping to Sweden. At the fuel prices and shipping prices you pay, it's well worth buying the quality part that will work for you.

[Walter R. Malik]

I thought that one of the old camshafts would be nice to valve train
I live in Sweden so it is easiest to shop at summit racing.

I anticipated that.
SUMMIT sells that Melling #22107 camshaft; $101.97