Lunati Cams

[Gilderbeast]

Hello. I was hoping I could get an answer. Im trying to pick a hydraulic roller cam out for my 1980 Chevy K30 ,454, nv4500, and 4:10 gears. I plan on stroking the motor to 496, compression ratio around 9.8:1, and putting edelbrock pro flo 4 efi on it. It has longtube headers as well. I don't care about gas mileage. The truck will mainly be driven in late spring to early fall, probably averaging 30-40 miles a day. I want it to roast tires, haul ass, and be able to pull a 22ft SeaRay to the nearby lake and back. The lunati cams I am looking at are part numbers: 20110668, 20110120, 20110121. Would these be good cams? Thanks.

 

[Preston]

Welcome to GMSB from Virginia


Don’t know too much about the cam, but you will have an answer very soon, sure would like to see some pictures of your truck and the conversion to a tire burning monster.

 

[Charlie]

 

[shiftpro]

Hello. I was hoping I could get an answer. Im trying to pick a hydraulic roller cam out for my 1980 Chevy K30 ,454, nv4500, and 4:10 gears. I plan on stroking the motor to 496, compression ratio around 9.8:1, and putting edelbrock pro flo 4 efi on it. It has longtube headers as well. I don't care about gas mileage. The truck will mainly be driven in late spring to early fall, probably averaging 30-40 miles a day. I want it to roast tires, haul ass, and be able to pull a 22ft SeaRay to the nearby lake and back. The lunati cams I am looking at are part numbers: 20110668, 20110120, 20110121. Would these be good cams? Thanks.

Welcome to the site Brett.
You can run any of these cams. They might seem a little large for something that might get towing duty, but you can generally run a bigger cam with big cubes like a 496.
What heads will you be using? If cast iron you will need 781 or 049 heads and you should at least put a bigger exhaust valve in it and the bowls under the valve can be opened quite a bit.
I would wait until the engine is built before you order a cam, you just never know how things unfold.
And you should consider a late 80's block as they are already clearanced for a big cranks AND they are 4 bolt main.

One last thing, if you hope to get high miles out of this engine, like say 150K, I would go flat tappet. You're only gaining a slight edge with a retro roller
with the trade off of reduced long term reliability AND a whole bunch more $$.

 

[Gilderbeast]

I am currently running 781 heads with stock valves. I have milled them .020. The block is a 79 two bolt main. It has been decked. I have main caps to get it splayed. I currently have edelbrocks performer cam in it. It is flat tappet with .500 lift and like 218 duration. Its a small cam for it. I think it could be way better. With the sequential port injection and efi I feel it would be able to handle those lunati cams. I also have hydroboost and no a/c so there would be no vacuum lines.

 

[CoggedBelt75]

IMO, I would talk to the cam grinder. Who would know more about this than the ones who do this for a living with tons of feedback from their customers? They can give you a more accurate answer, as long as you give them exactly what you have and what you want it to do. Lots of variables to consider.

 

[4WDKC]

One last thing, if you hope to get high miles out of this engine, like say 150K, I would go flat tappet. You're only gaining a slight edge with a retro roller
with the trade off of reduced long term reliability AND a whole bunch more $$.

Do you have sources of retro roller cams not being reliable for 150k miles ?

I am currently running 781 heads with stock valves. I have milled them .020. The block is a 79 two bolt main. It has been decked. I have main caps to get it splayed. I currently have edelbrocks performer cam in it. It is flat tappet with .500 lift and like 218 duration. Its a small cam for it. I think it could be way better. With the sequential port injection and efi I feel it would be able to handle those lunati cams. I also have hydroboost and no a/c so there would be no vacuum lines.

I didnt see a cam in there that I thought would make for low vacuum. I use this to help get an idea for cams, 230 degrees should come in under your stall and prevent lean bucking, but contacting a cam manufacturer will be the best option. They will want to know your compression,stall,gears tire size and weight of the vehicle so be prepared.. What efi are you going to be using?

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[QBuff02]

I'll throw my hat in the ring here. Lots of variables go into play when picking the right cam. For your application with the increase in cubic inches, the lack of a torque converter due to the manual trans and no vacuum brakes would dictate that you could get away with a cam a couple sizes larger than what the "book" calls for. However, it sounds like you want to build a torque monster. But out of the cams you have listed above, I'd put my money on the 20110121 based off of your desire and the cubic inches you are building to. "Off the shelf" Camshafts are designed to fall within a certain cubic inch "range". That's why you always hear people say for example "I had great luck and made tons of power with this *** cam in my 355 so I reused it when I rebuilt and stroked the engine to a 383 and now the power just doesn't feel like it's there anymore". Because larger cubic inch engines require more demand from the increased displacement. Think of it like a giant air pump, which coincidentally is exactly what it is, if you increase the volume of the pump, you also increase the demand of the pump, so you need to feed it more for any marked improvement. So you need an Increase in lift and duration and you can play with lsa and centerlines and cam timing until you're blue in the face. so to fully benefit from it is a question truly left for the experts. That's why stroker applications can really get a little tricky with camshaft selection. Grinding a cam on a couple degree different lsa can make a ton of difference in the drivability and power down low. Just as much as degreeing a cam or altering the timing of it (timing of the cam, not the ignition) can make or lose 25+ hp in certain applications. And then, are you going to do anything crazy with the heads? Larger valves, opening up the throats, porting, port matching, unshrouding? What intake? are you going to run stock ratio or increased ratio rockers? etc etc? Some people don't realize it, but Velocity is key to making good power. And then you want to throw fuel injection on top of it, so that is going to have to be figured into the mix as well. So at the end of the day, if you really want to get the most bang for your buck, do as stated above and call Lunati and have every shred of information on your build and vehicle available that you can, and they'll get you a cam that falls right in your wheel house. You won't be disappointed.

 

[shiftpro]

Do you have sources of retro roller cams not being reliable for 150k miles ?[/QUOTE

Cam tech from Lunati as matter of fact.

 

[Gilderbeast]

So Im not running vacuum accessories. The edelbrock pro flo 4 efi. It only needs 7 inches of vacuum. I don't have an automatic so no stall/torque converter. Two of those lunati cams are listed under towing on summitracing. Ive called multiple companies and the cam companies. They always tell me different cams to run. Id rather contact a engine builder. Compression will be 9.8:1, 4:10 gears, 29" tires, and 5500 lbs truck.[/QUOTE]

 

[Gilderbeast]

I'll throw my hat in the ring here. Lots of variables go into play when picking the right cam. For your application with the increase in cubic inches, the lack of a torque converter due to the manual trans and no vacuum brakes would dictate that you could get away with a cam a couple sizes larger than what the "book" calls for. However, it sounds like you want to build a torque monster. But out of the cams you have listed above, I'd put my money on the 20110121 based off of your desire and the cubic inches you are building to. "Off the shelf" Camshafts are designed to fall within a certain cubic inch "range". That's why you always hear people say for example "I had great luck and made tons of power with this *** cam in my 355 so I reused it when I rebuilt and stroked the engine to a 383 and now the power just doesn't feel like it's there anymore". Because larger cubic inch engines require more demand from the increased displacement. Think of it like a giant air pump, which coincidentally is exactly what it is, if you increase the volume of the pump, you also increase the demand of the pump, so you need to feed it more for any marked improvement. So you need an Increase in lift and duration and you can play with lsa and centerlines and cam timing until you're blue in the face. so to fully benefit from it is a question truly left for the experts. That's why stroker applications can really get a little tricky with camshaft selection. Grinding a cam on a couple degree different lsa can make a ton of difference in the drivability and power down low. Just as much as degreeing a cam or altering the timing of it (timing of the cam, not the ignition) can make or lose 25+ hp in certain applications. And then, are you going to do anything crazy with the heads? Larger valves, opening up the throats, porting, port matching, unshrouding? What intake? are you going to run stock ratio or increased ratio rockers? etc etc? Some people don't realize it, but Velocity is key to making good power. And then you want to throw fuel injection on top of it, so that is going to have to be figured into the mix as well. So at the end of the day, if you really want to get the most bang for your buck, do as stated above and call Lunati and have every shred of information on your build and vehicle available that you can, and they'll get you a cam that falls right in your wheel house. You won't be disappointed.

So I plan on upgrading the 781 heads with bigger valves, most likely attempt to port them myself. If I ruin them then I'll get some AFR aluminum heads. The intake goes with the efi. Its not throttle body its sequential port injection. Stock ratio 1.7 rocker arms. Don't want to mess up the geometry. The 20110121 is listed under towing on summit.

 

[Gilderbeast]

I lied. This is the cam listed under towing for 454 on summit.
20110711

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[CoggedBelt75]

Ive called multiple companies and the cam companies. They always tell me different cams to run. Id rather contact a engine builder. Compression will be 9.8:1, 4:10 gears, 29" tires, and 5500 lbs truck.

[/QUOTE]
You will get many different responses from them. Unless you are trying to wring every ounce of horsepower out of it, whatever they may tell you will be within reason. Even if you were to ask 10 different builders, you would probably get about 10 different answers. On that note....there is a place called KPE Racing on Huff Rd in the Falls, (940) 696-3278. They do a lot of the drag racers stuff in the area. Or just go to the local track in Iowa Park, 16 minutes from the Falls, on weekends and talk with the guys there. Lots of tested knowledge floating around in the pits.
If you do decide to go to the track, holler & we can meet up as my son & I go there quite a bit before my job kicks in July.

 

[Gilderbeast]

You will get many different responses from them. Unless you are trying to wring every ounce of horsepower out of it, whatever they may tell you will be within reason. Even if you were to ask 10 different builders, you would probably get about 10 different answers. On that note....there is a place called KPE Racing on Huff Rd in the Falls, (940) 696-3278. They do a lot of the drag racers stuff in the area. Or just go to the local track in Iowa Park, 16 minutes from the Falls, on weekends and talk with the guys there. Lots of tested knowledge floating around in the pits.
If you do decide to go to the track, holler & we can meet up as my son & I go there quite a bit before my job kicks in July.[/QUOTE]
Definitely will do! Thanks for the help. Id loved to come hang out. Theres nothing for me to so on the weekends on base and I have nothing to wrench on. I have my 97 K1500 with me down here though. Might trade it for a k5 if I can find a nice one.

 

[shiftpro]

So I plan on upgrading the 781 heads with bigger valves, most likely attempt to port them myself. If I ruin them then I'll get some AFR aluminum heads. The intake goes with the efi. Its not throttle body its sequential port injection. Stock ratio 1.7 rocker arms. Don't want to mess up the geometry. The 20110121 is listed under towing on summit.

Porting is hard work but again, it's also easy. The worst part is the mess. Stick the shop vac hose in the opposite end of the port you're working on.
Where these heads really benefit is opening the bowls and thinning and lowering the valve guide bosses. They are huge in the exhaust track.
These heads can support nearly 700 hp even with the stock sized intake valve. Exhaust valve at the least should be larger. THEN you can run a single pattern cam. Lots of controversy here... The larger/longer exhaust duration we see on cams is to make up for the small and restricted exhaust, so with large valves and the bowl open the dual pattern is not helpful anymore.

Another tip on your 781 heads... when replacing the valve guides, use the solid bronze bushings. Don't use the cast with bronze insert, they are inferior to solid brass. Also, solid brass conducts heat better. It's a propane MUST HAVE but there is no reason to not use them all around. They also seem to stay in place better than cast. The cast guides on the exhaust side can tend to move. When I was rebuilding engines at Aklands in the late 70's we knurled the cast guides and pressed them in with lots of green locktite.