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Author
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Topic: cleveland camshaft
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jim1320
Gearhead Posts: 189
From: white plains, maryland, usa
Registered: Apr 2003
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posted 09-17-2003 09:08 PM
   
Well working on rebuilding my 393 stroker i got the block back 0 deck bore 30 over . new pistons and rods the crankshaft was repair and rebalace. today find out the camshaft was damage . i need new roler camshaft any help what to buy??? i think going look aat custom cam comp cam looking at a 250 to 270 duration at 50 and 108 centerline or less and about 680 to 700 lift going to take heads back to machince shop to check spring height , iws running a comp cam custom 256 266 at 50 662 liftat 110 center line. the car is 70 mach 1 3550 lbs 393 cleveland 4v heads holley intake domintor 750 hp, flat tops pistons i think about 12 to 1 comp. best run was 10.99 122 mph 1.49 60 ft time c4 trans with a 3800 stall 9 inch , rear is 4.56 gear and 28 slicks shift 6500 rpm andgoing thur about 7200 7300 rpm thanks jim1320------------------
1970 Mach 1 393 stroker cleveland best 10.99 @121.50 3550 lb car with exhaust
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kid vishus
Gearhead Posts: 6098
From: middle of NC
Registered: Oct 2000
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posted 09-17-2003 09:40 PM
If you put a bigger camshaft in it, it will need a looser convertor. 3800 wont cut it with a cam the size you are talking about. It will leave like a dog. Granted it will run out the other end real well, but I wouldn't be suprised if your 60' times would get worse.I am going to assume you are already running a solid roller? Unless you like changing valve springs, I would try and stay around .650 lift. I have seen no difference in ET on my motor when I change my rockers and cut almost .050 off the lift. My cam is right at .650 on both, and it actually picked up a little when I put 1.6 rockers on the exhuast and cut the lift back to .605.
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Buster
Gearhead Posts: 1437
From: Hurricane alley
Registered: May 2002
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posted 09-17-2003 09:45 PM
Comp Cam's Link 35-780-9 Looks like a nice one....I bought a 35-781-9 and kinda wish I got that one. I'm going to run in advanced and see how it is. However, If it turns out to be too big, even advanced, I will get the 35-780-9.
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Buster
Gearhead Posts: 1437
From: Hurricane alley
Registered: May 2002
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posted 09-17-2003 09:48 PM
quote:
Originally posted by kid vishus:
Unless you like changing valve springs, I would try and stay around .650 lift.
About how many passes? [This message has been edited by Buster (edited 09-17-2003).]
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kid vishus
Gearhead Posts: 6098
From: middle of NC
Registered: Oct 2000
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posted 09-17-2003 09:59 PM
I don't really know. Maybe you can run more lift than that and be ok. I really don't know since I haven't ran more than that.I just know, that even with me running relatively expensive springs and not a lot of lift, we have to shim them after one season (around 200 passes normally), then replace them the next year. We started off using Isky springs, they lost a bunch of seat pressure in one season, and so much so we couldn't (actually wouldn't) shim them back up to spec. We then went to a tool steel Lunati spring that lasted better, but was still losing a significant amount of seat pressure in a years time. We did however run them for 2 years (shimmed the last year) before replacing them. I now have PSI springs on it, and they seem to be the best so far. But, they are also the most expensive.
Maybe I'm expecting too much longevity out of a motor that is making this kind of power.
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Buster
Gearhead Posts: 1437
From: Hurricane alley
Registered: May 2002
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posted 09-17-2003 11:41 PM
How much are a set of PSI springs?
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kid vishus
Gearhead Posts: 6098
From: middle of NC
Registered: Oct 2000
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posted 09-18-2003 08:04 AM
Since I bought them over 2 years ago ( the motor was hardly ran last year), I don't remember exactly how much I paid for them. I think I paid somewhere around $250 for the set.
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67357C
Gearhead Posts: 475
From: Newcastle, WA.
Registered: Aug 2003
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posted 09-18-2003 12:58 PM
quote:
Originally posted by kid vishus:
If you put a bigger camshaft in it, it will need a looser convertor. 3800 wont cut it with a cam the size you are talking about. It will leave like a dog. Granted it will run out the other end real well, but I wouldn't be suprised if your 60' times would get worse.I am going to assume you are already running a solid roller? Unless you like changing valve springs, I would try and stay around .650 lift. I have seen no difference in ET on my motor when I change my rockers and cut almost .050 off the lift. My cam is right at .650 on both, and it actually picked up a little when I put 1.6 rockers on the exhuast and cut the lift back to .605.
KV, along the same discussion as camshaft selection. I know a solid roller is extremely hard on valve train on a street car. can you get any better ramp speeds out of a hydraulic roller versus a solid tappet cam? and just curious if you pick up any more clearance? my piston to valve (as I remember, it was over 8 years ago) was down to .060 with a flat top piston, I thought that was kinda tight out of a cam with only 590 lift. do you think a 650 lift cam would clear if it were a roller?
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Tbird
Gearhead Posts: 298
From: USA
Registered: May 2003
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posted 09-18-2003 01:08 PM
Jim,What brand is this cam? If it is a Crance Cam, Crane use to have a trade in program where they will exchange a damaged cam for about half price of their list price. Not sure if they would allow a substitute cam number or not. They also required an adult signature at the door when it was delivered. The problem with going to stiffer seat springs is on a lot of engines, you need a longer valve length. Most times, at least +.100 to accomadate the 1.900"-2" installed height springs. If you know anyone that needs any +.100 valves, I have a brand new set of 2.19" and 1.77 (can be cut to 1.71) Ferrea comp plus valves I am not going to use. Kid, $250 is about par even today for a set of H11 valve springs. K-Motion are about the same price for their K1000H and others. [This message has been edited by Tbird (edited 09-18-2003).]
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kid vishus
Gearhead Posts: 6098
From: middle of NC
Registered: Oct 2000
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posted 09-18-2003 01:50 PM
I've heard both ways. The shop I used to use said they had put bigger rollers in motors that were originally flat tappet, and picked up clearance. But they also told me depending on the motor they would lose clearance. My motor currently has .065 int/.075 exh piston to valve clearance. It's not much, but it was the best I could get without fly cutting the pistons.Now some of my opinion. I don't like hydro rollers for a clevelands. The lifters are too heavy, and adding weight in that area on a motor that is already hard on valvetrain parts to me isn't very smart. Plus, the added weight causes you lose some of the benefit of them being able to open the valve faster. And they are expensive (in most cases.) I wont run one. I have had such good luck with solid flat tappet camshafts I see no reason to run a hydro roller (the last solid flat tappet cam I used ran exactly the same 60', ET and MPH as the solid roller I took out.) If you want to run a roller, put a street solid roller grind in it. They have ramps that are easier on parts, and yet still allow for the faster opening rate. But that's just all my opinion.
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jim1320
Gearhead Posts: 189
From: white plains, maryland, usa
Registered: Apr 2003
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posted 09-18-2003 09:27 PM
this is cleveland engine i call comp cam. they will regrind a cam for 115.00 ant cam and new custom is 310.00 thanks for writing jim1320------------------
1970 Mach 1 393 stroker cleveland best 10.99 @121.50 3550 lb car with exhaust
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