Reply With QuoteAndy it sounds like you already know what to do. If the PVR has been opened then it just gets more fuel. As far as the secondary PV, a plug seems to work the easiest then add 8 to 10 jet sizes to compensate for it.
Happy tuning
Kinda feel like I am beating a dead horse here but I am setting up a set carbs from scratch that I picked up for a very good price. 850 double pump with choke housing removed. Owner prior to me had played with PVR restrictions. I don not know what stock size is but the best I can tell they are a #57 drill or .043 now. Primary PV are boost referenced and I am thinking of just plugging the Secondary PV,Not sure. Do I plug Sec PV or reference the too.? Looking for basic start up set up on jet sizes and I think can fine tune from there. I could probably guess on jet sizes from other posts I have read but the PVR have me spooked. Motor set up is.
525 cu BBC
Dart Aluminum Heads 360.
Crane hyd roller 139651 In 244'/632 - Ex 256'632 durations are at .050. (I know more cam than I probably need)
8.1 cr / 1071 / 6lbs boost
CMI elbow top exhaust
Motor will be in a 29' deep vee offshore boat. Will see extended time at cruise RPM from 3500 to 4500 with a max of 6000 depending on prop.
Any help and insight will be appriciated. Found quite a bit of info from prior posts here but most of you seem to be running river rockets, not sure that makes any differance in set though.
Thanks again Andy. Sorry it is so long.
Andy it sounds like you already know what to do. If the PVR has been opened then it just gets more fuel. As far as the secondary PV, a plug seems to work the easiest then add 8 to 10 jet sizes to compensate for it.
Happy tuning
paradigm shift:
Kinda feel like I am beating a dead horse here but I am setting up a set carbs from scratch that I picked up for a very good price. 850 double pump with choke housing removed. Owner prior to me had played with PVR restrictions. I don not know what stock size is but the best I can tell they are a #57 drill or .043 now. Primary PV are boost referenced and I am thinking of just plugging the Secondary PV,Not sure. Do I plug Sec PV or reference the too.? Looking for basic start up set up on jet sizes and I think can fine tune from there. I could probably guess on jet sizes from other posts I have read but the PVR have me spooked. Motor set up is.
525 cu BBC
Dart Aluminum Heads 360.
Crane hyd roller 139651 In 244'/632 - Ex 256'632 durations are at .050. (I know more cam than I probably need)
8.1 cr / 1071 / 6lbs boost
CMI elbow top exhaust
Motor will be in a 29' deep vee offshore boat. Will see extended time at cruise RPM from 3500 to 4500 with a max of 6000 depending on prop.
Any help and insight will be appriciated. Found quite a bit of info from prior posts here but most of you seem to be running river rockets, not sure that makes any differance in set though.
Thanks again Andy. Sorry it is so long.Were those PVCR holes drilled for the previous owners motor or yours?
I would recommend to block off the rear power-valve, boost reference the primary and lower the primary jet size by one or two for compensation of the larger PVCR holes. Also install a power-valve that is NOT hi-flow rated to over-compensate the larger amount of fuel being let into the main wells.
The only other option to fix the PVCR holes are to drill and tap them for air correctors. It is a teadious job but at least this way you now have complete adjustability of this circuit.
Good luck on getting this carb up to speed. Email me if you need anything!
-Ty
Thanks for the input gnarley and hotcrusader. Carbs were drilled out when I got them from previous owner. I do not know what the stock size of PVCR restrictions are. I think the carbs were originally a 4781 list I think?
Hey Ty can a guy with machinist ability do this PVCR mod you are talking about. Special tools required? I know this sounds somewhat shade tree but why can't a guy just plug the holes and redrill to a smaller / stock size if they are to big. If I had the $$$ I would send them to you and let you work your magic on them. Besides I am the kind of do it yourself guy that likes a challenge.
[ September 23, 2002, 12:39 PM: Message edited by: paradigm shift ]
If your worried & want to replace the metering blocks go to the Holley website http://www.holley.com/HiOctn/ProdLine/Holley.html http://www.holley.com/HiOctn/ProdLine/CarbList.pdf & order the parts & do it yourself!
Replacing them would be the cheaper and easier option. Call up Braswell Carburetion in Arizona and give him your list number and numbers off the block, if you desire to switch the block out instead.
They can send you a new block, otherwise you can drill them, tap them, and install the air correctors, also available from Braswell. Otherwise give me a call and I can get you the tools and parts. I can't see it being higher than $20-30 dollars.
-Ty
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