Why no gains after head install?
09-15-2011, 04:18 PM
#146
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Hmm, well all I can recomend would be to get you fueling correct. Get what you command, on a 346 I typically shoot for 12.7-12.9 and between 26-28 degrees of timing. If you are running 12.1 that is pretty rich.
09-15-2011, 04:27 PM
#147
Hey guys if I didnt use any thread sealant on the rocker bolts could that be some of my problem. The runners are ported so much that the rocker hole is cut into the runners. I noticed it when i got the heads but forgot when i installed them. That is probably why i have some oil on some of my plugs? Could the intake and exhaust charges be leaking there to?
09-16-2011, 08:04 AM
#149
Well it has come to my attention that I should've shimmed the valve springs when i installed the cam. So once i get that done hopefully things will be good to go. I will still run a compression check to be sure and will be getting a dyno tune as well. So i hope that i was just getting a little valve float at higher rpm cause my loss of power.. (cross fingers)
09-16-2011, 09:11 AM
#150
Well it has come to my attention that I should've shimmed the valve springs when i installed the cam. So once i get that done hopefully things will be good to go. I will still run a compression check to be sure and will be getting a dyno tune as well. So i hope that i was just getting a little valve float at higher rpm cause my loss of power.. (cross fingers)
As with the rocker bolts yes that could be why you had some oil on your plugs. It also can be a source of a vacuum leak.
09-28-2011, 10:38 PM
#151
Just a little update. I have finally got the valve springs shimmed. Ended up shimming all of them .060 to get the installed height pretty close to 1.74 on all springs. That puts my max lift at about 1.152 which is about .060 to coil bind which is the advertised max from PAC for the 1518 springs, so I should be good on the springs.
Did a compression check on all 8 cylinders and they were all between 190-200 psi which I believe is pretty good. The check was done with the engine warm.
Took the car for a drive last night and it did seem to pull better from about 5200 to 6500 where as before it would kinda flatten out. Getting a dyno tune Tuesday, hope all goes well.
Thanks again for all the help.
Did a compression check on all 8 cylinders and they were all between 190-200 psi which I believe is pretty good. The check was done with the engine warm.
Took the car for a drive last night and it did seem to pull better from about 5200 to 6500 where as before it would kinda flatten out. Getting a dyno tune Tuesday, hope all goes well.
Thanks again for all the help.
09-29-2011, 03:43 PM
#155
which some ppl actually when trying to sell there car say it's like adding 50hp so their bolton LS1 they rate it at 450hp lol... don't add power, but can make drastic changes. Like me, I don't like launching hard as I hate breaking things so I went from 13.1s bolton tuned, etc. to low 12.4s lol... You go thru gears quicker so that's why you made your mods and didn't feel/see a difference. Go back with 3.73s or cheap find some1 with M6 car and get their stock 3.42s
09-30-2011, 10:47 AM
#156
We are done with the gear debate. His slight change in gears is not enough to negate a set of professionally ported 243 heads. Period. Results with an automatic cannot be compared to a manual here.
Gears will still give an auto the same impression of power, but it translates to very little at the track. Especially in MPH where the OP should have seen a significant gain.
Gears will still give an auto the same impression of power, but it translates to very little at the track. Especially in MPH where the OP should have seen a significant gain.
10-04-2011, 08:35 PM
#157
Ok here is the verdict. Went to Brett at XP Racing in OKC and he did a good job with the car. He didn't make a pull with my tune in the car but on the first pull after he changed some things the car made 388hp and I believe 366lb fts. Here is a graph of the final pull. What do you guys think?
