Vacuum is one thing to check but doesnt sound like it would cause heat issues

Is the head gasket sealing good?

 

yeah as far as I know. I have no over heating when i get into boost or problems with it pushing water in to the over flow. I dont like the low vacuum. 8 inches with a small cam on a big inch motor isnt right and if it has a leak will make it go lean causing it to get hot in the pipes. i am wondering on the cam being retarded also if that is affecting things. I am seeing over 2000 degrees with a wideband reading of 11.8 and plugs look good. the closer to the head the hotter. fine in the down pipe. i have a big exhaust housing too. something weird is causing this.

 

This may mean nothing because I am a diesel guy but..... We tune based on EGT's. High EGT's happen bacause fuel is being added after the piston has hit TDC and we chase it back down the hole. At WOT my injectors open to add fuel at about 32 degrees BTDC. With my tunning, the injectors quit adding fuel at about 30 degrees ATDC. If I go any longer EGT's get stupid, (over 2000 degrees F). I know it is not the same but the theory is still there. Your EGT's are high and it is rich and that tells me that fuel is entering the exhaust and is being burned. Maby cam timming. What is the A/R of the exhaust housing? Maby it's a little too big.

Phil

 

i was thinking cam timing i do have it in retarded to go with the once stock tpi intake it is a easy way to pick up 30 or so hp on a car with a restrictive intake manifold might be hurting me now. as the ar it is .96 I do have a 383 big inch motor so not 100% on it but thought that was about right for my motor if not almost too small???

 

why do you say retarding a cam in a motor with a stock tpi intake makes it better? i would think that since you have a cam with 232 @.50 that its already way to big for a stock intake, to retard it moves the power band up even higher. moving it even farther away from the band the intake was built for. where adv the cam would bring the cam's power band down, and help it make more TQ. where retarding it would kill TQ and since the intake doesn't match, you dont gain the hp up top to make up for the power lost down low. retarding the stock cam a bit may help, but i doubt it with big cam.


unless i have this all wrong, but i'm pretty sure you need to install that cam straight up, and fatten up your idle a/f to high 12's ish, or whenever your plugs look good at.

 

when it had a ported stock lower and upper with slp runners i picked up 30 rwhp and it wasnt peak. it was through out the band. i also picked up over 20 lbs of torque. dynoed the car with it straight up then advanced. not only does it move up the power band but helps scavange the intake gasses and why it makes a intake that doesnt flow well act better. this is a very old trick that guys using stock q-jet intakes were doing back in the 70s in the stocker classes. it is in the tpi secrets book also. My car with mostly stock stuff and the factory cam moved around(never checked it) 4 degrees retarded was running 106 in the quarter. 108 in the winter. 1992 formula. I had a lot of people baffeled with this car. when it had the heads cam and factory intake was getting 118 out of it. show me another stock( well ported) intake car running that much mph in the quarter. believe me it works but only if the intake is restricting the rest of the combo in which a tpi intake was built around 305 inches and a fairly large cam. any way i think it is now hurting the hsr and turbo combo on the car. hsr isnt a restriction on this by far. plus being forced injected now.

 

well last night driving around was great. adding all the timing to it cured the egts at cruising but at wot it still got hot but with all the timing it leaned out a bunch. I was seeing 12.0 to 11.5 wot and last night saw up to as much as 14.0 wot on 5 lbs so reason enough to get i I guess. That lean will make it hot right??? even at that the car is way faster with being lean on 5 lbs and it spools up like right now. It is like a blower i touch the gas and have 5 lbs. come off a light driving normal and have to back out to keep from spinnning the drag radials. it want to be at 5 lbs with 15% tps spool up is instant. Now i need to get it re tuned for fuel with my new timing and see where it goes. ran one car last night and when i saw how lean it was. it was a 1996 I think rx7 with a ls1 in it and a t-74 turbo very sweet setup. made 550 on 5 lbs. 2800 lbs car and from a slow dig were real close but my car pulls harder up top. started walking off in 3rd and saw 14.0 and shut it down and was done for the night. Never cooked a plug wire and just that is like winning the lotto. Never changed a wire last night or blew a gasket and that was so nice. So all that have been following remember this timing is your friend. below boost as much as you can. My map is very agressive with timing and the car loves it the fact it makes boost so fast proves it and the actual temp of the car(water temp) is down about 40 dergees all over. going to advance the cam back later on as i now see a oil pan leak and need to pull it any way. will do a follow up just to be sure adding the fuel brings it back down in boost.

 

yeah it should

bring it back down to 12 or so or even more and it should cool off i'd think. So you just added timing to your low map/low rpm areas and it is running good now??

 

yep timing in the lower map cured so much and made it drive so good now. no more cooking wires or gaskets. engine temps are down and more torque. all over a little timing. I did a post a while ago on show me you timing tables and looking back now so many people are way off on timing. I am very agressive with mine and the car loves it. People are erroring to the safe side thinking and probably doing as much damage as if it was too much. you can hear pinging but cant hear when you are melting all the stuff under the hood. this has been a huge lesson for me i have asked so many people what to do and no one until the guy with the truck said to give it more timing. my buddy with a eclipse told me that adding 4 degrees timing to wot brought the temps down 600 degrees and that gave me the idea to give it a bunch in the lower map. It was so hot driving that when i did go to boost it just carried over and i thought it was off everywhere when it was not up top just carrying the heat over from cruising. I need to find that old post and put up my new table for those to see they can go more with it and get great rewards. I know not all engines are the same but remeber seeing some that were very conservative. maybe they had iron heads. I know typically afr heads dont like a bunch but some reason mine does.

 

At 5lbs of boost how much timing advance are you running?

Ray