hpfiend

I did some research and apparently the cam from the L46 corvette which had a 350 hp/350 is still available and they used the same cam in the low compression L82 350ci corvette. Federal mogul calls it the CS1095R and a lot of old corvette guys are using it... The best part is it has specs similar to the custom grind but with lift I can get away with on these heads... 224/224 at 0.050 .450/.460 114 LSA I figure if I can't boost up to low 10s then I can add some aluminum heads and higher ratio rockers to get the flow there... Well, I put it in with new lifters, pushrods, sparkplug wires, and those short accel spark plugs (burned up #6 plug boot apparently) spent all day Friday trying to figure out this terrible sound on startup (readjusted valves twice, pulled electric fans, adjusted timing (thinking it was detonation) which apparently was the flex plate hitting the dust cover as I must have bumped it when I removed that @&$@ filter when I changed the oil...broke the cam in, test ran it, looked for leaks, and changed the oil again... Got to the event at 4:45 as most of you were leaving- as tired as I was I didn't want to change tires to slicks- stayed for the trails event and it got a 14.6/14.7 at 98.x mph. The dead spot is not gone but it seems to pull a lot harder and shows about 3mph faster than we got at marion. 60fts were 2.6 to 2.9 as it falls on its face and then spins when it takes off after you pump the gas a few times to get through the dead spot. So even though it ran slower I am not concerned as it was mainly from running on street tires. Going to try to find a 650 dp to try to see if that helps with the dead spot...

Okay after talking with MSD and Holley tech support again they now both think the cam is the problem. I had comp cams recommend a cam for this engine with a turbocharger in it and they came up with a reverse pattern cam of 230/228 @ 0.050 and .525/.525 lift. The problem was I needed roller lifters and bigger springs. As the numbers of the block indicated 1980-85 and I shot an email to the previous owner and he didn't think the rollers had been updated- that made the cam swap very expensive. Double hump heads don't have spring seats big enough for that cam, link bar roller lifters were 400, and the custom grind was 300 I had some decisions to make. I contemplated putting an ls truck engine in with engine mount adapter plates but was afraid of the hassle of tuning/wiring fuel injection mega squirt and an msd multi-spark, fuel pump, injectors etc and with a carb manifold and the plates we may not be able to fit the stock hood anymore.. Sooo...

Next we tried to fix the deadspot with timing. We took the msd dizzy apart and replaced the blue bushing with the black one and put the two light springs in instead of one light and one heavy. This should bring in 18 degrees by 1600 rpm. We then upped the base timing to about 16. The car seemed to pull a little harder but the dead spot was the same... Btw does anyone know why the timing pointer is in the center at about 12 o clock behind the water pump as opposed to the 2 o'clock as is customary? A different balancer? We even bought a pointer from jegs for an 8" balancer and it didn't work (duh- not sure what we were thinking perhaps blinded by optimism). We then tried position 2 on the pink accelerator cam in the front and one in the back. I think this helped at little with the deadspot but it's definitely still there...

It's got a mini starter and we replaced the ignition switch which has helped a lot... A heat shield and or a ford remote solenoid are next- it happens more rarely now but still present- thanks! We pulled the hp 750 carb off and went through it to see what was in it... As the vacuum at idle in gear was about 9 we put a 4.5 power valve in the front- the back had no power valve but did have jet extensions and a plastic notched float. It's got 72s in the front and 84s in the back, we took all the slack out of the accel pump linkages (there wasn't much to begin with) and discovered that the hp main body upgrade has no provisions for the timed spark port (which would explain why it showed no vacuum). We put it back on and tried it out.... No change...

Thanks guys! I thought I could pull it off as we bought the car this way but the Holley calculator calculated a 600cfm carb as ideal... Replacing the pro stock sounding cam has helped but still pretty lazy and downright abominable below 2500- gas consumption is unreal as well

Hey all! Looking for a Holley 650 double pumper to borrow a few days... I have a dead spot below 2500 rpm I can't get rid of- I am thinking with the low compression (dished pistons) 355 sbc, 2.56 gears, and supposedly a 3000 rpm stall- maybe the hp750 I have is too big...the cam should have good bottom end though it sounds more lopey than I would have expected for such little duration.

Thanks guys! Just found out I don't have a roller block... Are the link bar lifters worth the 400 they cost or am I ok with a hydraulic flat tappet cam? The guy at comp cams said I would have to use special oil always, break in procedure, and may wipe a lobe... Also found out the heads need to be machined for springs capable of handling .525+ lift under boost ~130 seat pressure... I am half wondering if I should get some of those sbc to ls mount adapter plates and run a junkyard 5.3 ls with the same carb and a zr1 cam or at least the same cam but don't worry about the roller issue and have better aluminum heads and rotating assembly.. Could probably sell this sbc airgap manifold and msd dizzy but dunno if a carb ls1 manifold would fit under my stock hood like this one does... Thoughts?

Thanks! It looks like the s475 is the cr favored option to get and play with the housings to minimize lag... I am building the headers so a t6 flange shouldn't be an issue. I am trying to learn as quickly as I can but isn't a s475 a 75mm turbine? With the right A/R housing wouldn't the 76mm make more power? Or are those housings just not available? What makes a good versus a bad wastegate? Aren't they a pretty simple design? Does anyone know of a website or shareware that will plot various boost levels and rpms, CID on a compressor map to test for a match or should I see if I can make something up myself- kind of tedious to do it manually? How do tell spool or lag-factor from those efficiency maps? Is it the cutoff at the bottom? The reason I ask- and I will have to double check but the T76 map I saw was very similar to the S475 as far as the flat level rpm at the bottom...

Thanks guys! AJ are they big enough just to use one?? I really only have enough room on the drivers side for the one turbo and the other side I need room for the air to water intercooler... There isnt really enough room in the front for an air to air and the associated plumbing

Hey all- 2700 lb gremlin 355 sbc, 3.73 gears soon , th350 with 3000 rpm stall, shooting for low 10s in quarter from a blow through single turbo carb setup- from my limited experience both the bullseye s475 and master power t76 look pretty good, which would you go with and why?- are there any on3 maps available anywhere for the 76mm? Thinking 15 psi should be enough.. Need about 650 rwhp I believe... As the car currently runs low 13s at 95 mph that puts it what 250 rwhp? Going to put a cam and the new rear in soon as it has one too large and only 2.56 rear gears now....

thanks guys! the 335 twin turbo does seem to fit the bill but I don't want a german car. My wife's acura rl does primary family duty but I feel I would get mote use out of my car if it had a backseat. I am tempted by the terminator mustangs as I do miss my old fox a lot!

Hey all- With two kids now, I have really been thinking about the Mitsubishi Lancer Evolution... I don't know how spacious they are but it would be sweet to be able to fit 2 car seats in the back, be driveable in the winter and handle decent enough year round... Besides one of our track events had an 8 or 9 sec evo that looked pretty stock on the outside.... I LOVE the looks and performance of my unmodified corvette.. I drive it every day to work that it's not snowing but it sits on the weekends and most of the winter... frankly the looks of the Evo and the fact that it would have to be modified and the hassles associated wih that do not excite me... The ctsv is appealing as well especially the wagon but snow duty is still out of the question...

awesome! Anyone know off hand if the sbc camel hump/double hump/fuelie heads of the 60s were siamese?

Nice work! Tell me about these truck manifolds? You just reversed sides and flipped them and then came off of them with the rest of your hotside piping- I am guessing the head port design is such that flipping them doesn't cause a sealing issue or restriction? Interesting!

Hey all looking for opinions-- goal is to run low 10s in a 2700 lb chassis Probably 650 rwhp to do it consistently without some crazy expensive chassis/suspension work? It has room for 26x10.5 slicks and is just a leaf spring rear suspension with traction bars as it sits. Have a big engine in a little car (sbc in an amc gremlin)- headers had to be dented in pretty well (by the previous owner) to clear the steering rods and the frame rails. They are so close that they occasionally make contact with the shake of the lopey cam. Running the headers forward and up/down for a big single turbo would obviously avoid this situation but there would be a lot of down time on the car to build the headers. Also with the large radiator and transmission cooler really only room for a water to air cooler or a drag only ice intercooler setup without a condenser... I have made headers from scratch before so it would be easier this time but time is previous with two kids and work. Are there any high enough flowing SBC manifolds I may be able to use/flip to save time on hotside fabrication? Slap a centrifugal blower on there and cog if needed to get the boost needed to force through what I have now or use the same high flow manifolds from an old vette or something of the like might offer better flow (or at least compared to the dented primaries I have now) and fit a lot better. I have tons of room in the back for a rear mount turbo setup (gas tank removed for a fuel cell in trunk) but dont know if the headers/manifolds would flow enough to make it work right... pretty much stuck with a gen 1 sbc as the mounts are custom and made for that and I have no desire to start over from scratch with the swap (Been there, done that). Obviously my goals would be easier with an LS anything but lots of guys have made plenty of power with the gen 1 sbc. while it would be sweet, a NA setup (DZ302) is probably out of the question unless I were to completely rework the firewall, floorboards and tunnel and make a proper set of rear facing headers... maybe juice it a bit as well for those power numbers and be *cough* reliable. Thanks for your opinion in advance!

Hey all- I wasn't sure where to post this but I wanted to make sure I gave an e-five to Kevin and his body shop Clifford Automotive. My wife or I- the verdict is still out- had a nasty altercation with the garage door brackets and the bumper of our metallic blue/grey/silver acura- Basically we should have not tried to cram it in the garage with the mower in front of it and shut the door- It scratched almost all the way down and then reversed and all the way back up. Soo- on recommendations from this board I took it to Kevin and for a very fair rate he made it look as good as new, detailed it thoroughly, and fixed another ding in the door that had been an eyesore. When I was there he educated me on the process and about paint intricacies in general and I had a great time. Really good guy and a great business! Thanks again Kevin!

You may have posted this elswehere but what are you doing about a rearend?

Thanks! I know the heads arent ideal but I was going to see how far I could get on the turbo before putting some aluminum aftermarket pieces on there...

Hey all What cam do you guys recommend for a low compression 355 sbc, th350, 3.73 gears (for now), 3000 rpm stall, 2700 lbs and a single 76mm turbo- air to water cooled probably under 18 psi... (soon) I know I want milder duration and small overlap but that is about it- I would guess as much lift as possible. It has iron 1.94 double hump heads for now... It has a huge cam in it now wih 9 inches of vacuum and terrible low rpm dead spot... Sounds mean but runs poorly until you beat on it

Fwiw I don't think this will work for you with a c5z. You need the techII in addition to the magnet in order to unlock the programming which is turned off in the Z06. If I am wrong please let me know as this has been on my list for a while to do... Also there are two types of sensors and only one will work in the z06 as they were all 01 and newer... I think the sensor date is 00 and newer and 00 and older

Hey all- What is the advantage/disadvantage to bringing timing in with increasing rpm versus bringing it all in at once? Other than starting issues why don't cars come from the factory with locked timing or better yet full advance from 1000 rpm to redline to help starting? Is it a longevity issue???? It seems like a lot of wasted engineering between vacuum advance and mechanical advance to just throw out the window as I am being instructed to do.

Pep Boy Futuras cost me my '96 Formula as a result of a hydroplane in standing rain that caused it to spin out of control into a concrete wall......

Software?

Does it have any software on it like word processing for example?

awesome replies guys thanks! I don't know how I missed these...