|10-15-2012 12:59 PM|
I did measure up the port opening of the exhaust port and it measures 1.4" wide and 1.35" height. So it's smaller than my 1.5/8" headers. So that shouldn't be a problem or what ???
|10-14-2012 07:55 AM|
I needto measure up the port size of the head and then the opening of these headers. Will post the results here when i'm finished !
But i did ran it like this with the low compression and small roller cam and it did just fine i think, wasn't laying off anywhere in the powerband and spun very quickly and easily to 7000 rpm's
But i agree with you they might be bigger these headers. Maybe 1.3/4" headers should do the trick !
|10-13-2012 08:41 PM|
|vinniekq2||Im really curious as to how well this combo of 235 cc heads and 1 5/8 headers is going to work?Im using 1 7/8 headers and only 227 cc heads|
|10-13-2012 03:19 PM|
|Icejeep||Yes hopefully this thing will be pretty fast as i would like to run in the 10's on next season !|
|10-13-2012 02:06 PM|
Thank you for all your advice sir. I will contact some cam company's / grinders during next week and then i'll let you know how things work out.
I remember that with the small street roller cam, 2400 stall holeshot converter and 4.10 gears it would go through the traps at 5700-5800 rpm at 117-118 mp/h. It was slow of the line but still i found that it would finish the first gear at 6500 rpm shifts very quickly. 60 ft times were only at flat 2.0 seconds. Hopefully i will do better with my new high stall converter.
Thanks again !
|10-13-2012 01:52 PM|
I like this budget solution for the fuel system, as it's set up now i'we got one 6 gallon cell in the trunk and one Holley Blue pump that pumps through 1/2" line into Holley fuel pressure regulator that has two 3/8" lines that go to the Carburetor. Would this system compensate for the dual Carter set up on the motor alone ?
How high do you think i need to spin a motor like this ?
|10-13-2012 01:25 PM|
I think it's almost sold ! I have to look around here for a combo like this !
But tell me what do you think about my rear gear selection, on or off the nitrous ?
|10-13-2012 12:53 PM|
Thanks for your advice sir. I do have a couple of questions though !
What do you think about my gear ratio ? Should i lower them gears or just try it out as is ?
This cam seem's huge for my compression atleast bigger than what i had in mind,, but i take your advice on it sir !
As well as i like the looks of a Tunnel Ram i think i will stick to the Victor intake for now. Because this time the money goes into rebuild this engine and purchase a nitrous system and bigger fuel system along with the new transmission and converter.
Thanks again !
|10-13-2012 12:20 PM|
Ok here it goes the complete run down..
Block -GM 4bolt mains #3970010
Crankshaft - GM cast #3932-442 3.48" stroke
Connecting Rods - GM x-type with ARP bolts and polished beams.
Pistons - Probe flat top -4cc VMS75 forged 10.5:1 compression
Heads - 235cc pro topline, 2.08"/1.6" valves 64cc cnc chambers
Intake - Edelbrock Super Victor #2925
Carburetor - Holley HP 950 cfm
Headers - 1.5/8" long tube w. 18" collector extensions (thought they were 1.3/4" but I'm wrong)
Ignition - MSD Pro Billet distributor with locked timing and 6AL
Car weight is 2900 lbs race ready and has following parts.
Th350 (now w. T-brake) and 5500 stall 8" converter.
GM 12 bolt with 4.10 gears and spool.
Tires are 29.5"x13.5"x15" slicks.
I'm also thinking about running a small nitrous kit next season, 150-200 HP nos cheater kit
|10-13-2012 09:39 AM|
So it would be a strong combo with 10.25-10.5:1 compression ratio and the #12-769 cam with the Victor intake. Where should this engine make it's peak power ? Just thinking if my 4.10 gears are good enough for this moderate combo!
As stated above this particular engine with a Performer dual plane intake and only 8.75:1 compression ratio ran 118 mp/h in the 1/4. But now i like to go faster !!!
|10-11-2012 08:32 PM|
I like this plan, except that this engine must run on 93 oct pump fuel so i belive 12.5:1 compression is out of the question. I also would like to use flat top piston in this engine, or at least with as small dome as possible. Camshaft will ofcourse be solid roller. Just haven't decided if i should go with wilder one then this i have now... Everything else is pretty much sorted out though !
|10-11-2012 01:01 PM|
Pistons and rods for sbc 350 ?
With more compression (12.5:1) it will have more cylinder pressure to make more power. Then going with a larger camshaft (mechanical roller) is addition power. The Super Victor will be ideal for your race engine. Don't skimp it's time to play.
|10-11-2012 11:01 AM|
|10-06-2012 09:20 AM|
Thank you for your answer Bogie. As you may not have noticed i'we decided that this engine is just going back to my strip car, but with some modifications. Last time it was together it had stock bottom end with aprox 9:1 compression ratio, the comp cams street roller cam #12-769. Heads are and will be 235cc RHS with 2.08"/1.6" valves, the intake was regular Edelbrock Performer. It has 850 cfm holley hp carb and pro billet msd dissy with 6al ignition box. So as you answered my question really well for offroading. Does a drag race engine take the same abuse as you mentioned above or is the abuse different regarding pistons and rods ?
As the engine was above it ran 118 mp/h in the 1/4 mile at nearly 3000 lbs. But now i want more compression along with maybe bigger camshaft. Also i'm going to put a single plane Victor intake on the engine now.
|10-05-2012 12:32 PM|
If those assumptions are good, I certainly wouldn't use hypereutectic pistons and rebuilt stock rods. This kind of usage drives on a better rod and a forged piston, however it doesn't need to be a 2618 alloy take me racing piston; the high silicon types of VMS 75 or 4032 alloy offer high strength, though not as much as 2618, but with better in-bore dimensional stability. Given your climate I think that the high silicon alloy will be better as it can be run with a tighter skirt clearance when cold, where the 2618 has to be warmed up to get the proper clearance and if shock loaded before that happens they risk cracking a skirt especially with piston that have no pin offset as these allow the piston to snap over hard as the thrust loading changes direction. The high silcon alloy's tighter fit and especially if combined with an offset pin keeps you out of this area of potential damage to the piston and provides a more stable ring alignment which is better for oil control and power output. I'd run a gapless second ring set on this like the Total Seal or Childs and Albert.
For a rod that perfoms way up scale from what it costs the SCAT 6 inch (also in 5.7), floating pin part number SCR6A7 is one tough customer. It has several features I really like in a high RPM engine in that it uses cap screws to retain the cap, 7/16ths ARP in this case and it has a centered strap section on the cap to beef it up so it doesn't distort from the jerk loads at high RPM when the piston is pulled down on the intake stroke. In addition, toward reinforcing this problem the cap locates into the shank with dowel pins which help react the resulting pinch loads from the jerk down, also, the interface boss is extended outboard of the fastener which enlarges the pinch load reaction platform to also help keep the cap from both side loading the capscrews and from bending the cap to where it pinches the rod bearing inward at the cap to shank interface. This is the sequence that is the start of the most common rod failure. As the piston is jerked down the bore at high RPM, the cap wants to stretch in the center. This causes the interface at the shank to bend open on the bearing side and close outboard of the bolt. This wants to bend the bolt and push the bearing edge into the rod journal. When this happens, the oil wedge is wiped out, the bearing overheats grabbing the journal then it spins in the rod's big end bore. When all this finally seizes the rod gets ripped apart just above the big end. The design of this SCAT rod provides as much resistance to this initiating event as you can put into a rod. you've got to look upscale to Crower and Lunati rods to find a comprable design. For some close up pictures of this thing follow the link White Performance Detail Description This is a lot of rod for the money.
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