My Burb is getting tired

30-A rider · March 30, 2006

I dont know why I love this one so much. This is my 4th Suburban and Im attached. Its a 1993 K1500. Had it since new and now has 236,000 trouble free miles on it. Never even did a trans and this thing has towed cars and boats up and down the Eastern US. But shes getting tired, and engine is gonna need a rebuild soon. I have done many small blocks, but most pre 86 (2 pc rear main seal). So as lots of you know these 350 TBI motors have lots of torque up to about 2500 rpm then get weak. My plan was to get block bored .030 over. cut crank 10/10, recondition factory rods with ARP hardware. Piston I planned to stay with cast but get the compression up to the 9:1 region where Id bet stock is most likely about 8.25:1. Heads was gonna get re fitted with SS valves and new springs. Ok now the question is cam. I dont know what the specs are on the stock cam, bvut Id bet the duration and lift is waaaayyy low. So any recomendations please do so with the cam, and also if any head mods can be recomended please do as well. Finally any other things that must be addressed with the cam change if anyone knows?

bobcat5544 · March 30, 2006

I dont know why I love this one so much. This is my 4th Suburban and Im attached. Its a 1993 K1500. Had it since new and now has 236,000 trouble free miles on it. Never even did a trans and this thing has towed cars and boats up and down the Eastern US. But shes getting tired, and engine is gonna need a rebuild soon. I have done many small blocks, but most pre 86 (2 pc rear main seal). So as lots of you know these 350 TBI motors have lots of torque up to about 2500 rpm then get weak. My plan was to get block bored .030 over. cut crank 10/10, recondition factory rods with ARP hardware. Piston I planned to stay with cast but get the compression up to the 9:1 region where Id bet stock is most likely about 8.25:1. Heads was gonna get re fitted with SS valves and new springs. Ok now the question is cam. I dont know what the specs are on the stock cam, bvut Id bet the duration and lift is waaaayyy low. So any recomendations please do so with the cam, and also if any head mods can be recomended please do as well. Finally any other things that must be addressed with the cam change if anyone knows?

<{POST_SNAPBACK}>

OEM CAM LIFT IS INTAKE 0.2565 EXHUAST 0.2690 I DONT KNOW WHAT THE DURATION IS

YOU BEST BET IS TO GO ON LINE TO SUMMITRACING SELECT YOU VEHICLE GO TO CAMS AND LOOK AROUND I WILL GIVE OPTIONS FOR WHAT TYPE OF USE YOU WILL BE USEING YOUR BURB FOR (RACE, STREET, STRIP, TOWING,TRUCK)THEN IT WILL GIVE DIFF CAMS YOU CAN BY FOR WHAT YOUR DOING WITH THE BURB

FAR AS OTHER THING YOU WILL NEED IT SOUNDS LIKE YOU HAVE IT COVERED

FivePointSevenLiters · March 31, 2006

I am currently rebuilding a 5.7L TBI GM 350.

http://www.cjavery.com/350Engine-PageComplete.htm

I am going with a 204I 214E Duration @.05 with .420I .442E lift.

It is a mild cam by standards, but I'm not looking for more than 295Hp after rebuild. I sent the heads out for tank, mag, keepers, seals, springs, valve guid check, and valve check. Did not replace the valves.

Trying to stay on somewhat of a budget however, I am sending the block out soon for tank, magniflux, cam bearings, hone, and decking if required. I feel a little bit more comfortable having them change the cam bearings. I am planning on using the factory pistons for rebuild. The engine came out of a 96 van with about 140k and running.

Good luck & enjoy...

RaysZ71 · April 2, 2006

I dont know why I love this one so much. This is my 4th Suburban and Im attached. Its a 1993 K1500. Had it since new and now has 236,000 trouble free miles on it. Never even did a trans and this thing has towed cars and boats up and down the Eastern US. But shes getting tired, and engine is gonna need a rebuild soon. I have done many small blocks, but most pre 86 (2 pc rear main seal). So as lots of you know these 350 TBI motors have lots of torque up to about 2500 rpm then get weak. My plan was to get block bored .030 over. cut crank 10/10, recondition factory rods with ARP hardware. Piston I planned to stay with cast but get the compression up to the 9:1 region where Id bet stock is most likely about 8.25:1. Heads was gonna get re fitted with SS valves and new springs. Ok now the question is cam. I dont know what the specs are on the stock cam, bvut Id bet the duration and lift is waaaayyy low. So any recomendations please do so with the cam, and also if any head mods can be recomended please do as well. Finally any other things that must be addressed with the cam change if anyone knows?

<{POST_SNAPBACK}>

The stock compression is something like 9.3:1.

30-A rider · April 4, 2006

Wow. FivePointSevenLiters...those cam specs are exactly what I was guessing as I saw them advertised in a summit catalog. I dont remeber which manufacturer it was, but thought it would be a hell of a lot better that the stock...good compromize between torque and now having some passing gear power above 2500, and should pull well to about 4,200 is my guess.

Rays Z71. Thanks for the input but keep in mind my 93 is not a Vortech head equipped motor...if Im not mistaken they are a typical smog head with a 76cc chamber where the Vortechs are 64cc. The difference between those head chamber volumes equals typically on a 350 engine 1.3 compression points. Therefore your sugggestion of 9.3:1 on a Vortech head motor would be 8:1 on a 76cc head motor with the exact same bottom end.

Now I could be wrong...maybe my 93 motor is Vortech equipped, but I have never head that. So if anyone knows either way for sure please do chime in. I would be very happy to hear they are vortech heads, as then I would know my cam swap would be a huge performance gain throughout the power band of the motor if they were as compared to standard 76cc chambered heads.

thanks for the input for those who have replied so far; any other with smarts on this please chime in, as all opinions are very welcomed.