What Throtle bracket to use 2bl to 4bl upgrade

[kpiazzisi]

Re: What Throtle bracket to use 2bl to 4bl upgrade

Thanks for the link. It looks like I can oder secondary jets from Eddlebrock. A mercruiser service bulletine I found (http://www.boatfix.com/merc/bullet/93/93_15.pdf) shows the non vortec V6 came with secondary jets "ED" stamped on them? What I can't figure out is why the rods used in the 5.0L engine using "CL" have a larger power tip (.0667) then the ED (.0567). If I am understanding this correctly the larger power tip = less fuel because it restricts the total metering area b/t the jets and the rod? What secondary rods do you recomend assuming I have the "ED" ones in there now?

If I am bogging on transition into the secondaries It's either the secondaries are opening prematurly (possibly wind up spring adjustment) or not enough fuel at the higher RPM (secondary metering rods)? It seems like changing or bending the hanger can also effect the mixture, which is probably why Carlos had me bend my hanger. Nothing I read mentioned anything about inspecting the spark plugs at diffent RPM ranges to determine tuning. I would think that this would be a good method in a boat? My thought was to put in a brand new plug, run the engine at cruise for a couple of miles then inspect? That would tell me the primary side, then I could do the same for WOT. What do you think, would this work?

I wish I would have just saved my money and purchased an Eddlebrock 1409 with the metering rod kit designed for a 4.3L vortec, oh well live and learn.

 

[Howard Sterndrive]

Re: What Throtle bracket to use 2bl to 4bl upgrade

I wish I would have just saved my money and purchased an Eddlebrock 1409 with the metering rod kit designed for a 4.3L vortec, oh well live and learn.

The 1409 was about 4 times the price as I recall when buying mine. unless you want a rebuilt 1409
You have to watch a lot of Edelbrock resellers are dealing a 350 dollar 1409, but I think that is the rebuilt... and who knows what that is... maybe batches contracted to I5

 

[christoner2002]

Re: What Throtle bracket to use 2bl to 4bl upgrade

If you want the qjet book I have, shoot me a PM. It is written by Cliff Ruggles. He seems to really know his stuff. And he sells jets, and metering rods etc. His site is http://www.cliffshighperformance.com/

On the 1409, I paid under 400 for it, brand new, and the adapter for the spread bore shipped to my house. Edelbrock's site has a reconditioned on, with the part number of 9909, for $289, but they are out of stock. I paid 265 for my I5 paperweight/anchor.

 

[John_S]

Re: What Throtle bracket to use 2bl to 4bl upgrade

The 1409 was about 4 times the price as I recall when buying mine. unless you want a rebuilt 1409
You have to watch a lot of Edelbrock resellers are dealing a 350 dollar 1409, but I think that is the rebuilt... and who knows what that is... maybe batches contracted to I5

Jegs or Summit, $350 for new ED 1409's.

 

[John_S]

Re: What Throtle bracket to use 2bl to 4bl upgrade

Thanks for the link. It looks like I can oder secondary jets from Eddlebrock. A mercruiser service bulletine I found (http://www.boatfix.com/merc/bullet/93/93_15.pdf) shows the non vortec V6 came with secondary jets "ED" stamped on them? What I can't figure out is why the rods used in the 5.0L engine using "CL" have a larger power tip (.0667) then the ED (.0567). If I am understanding this correctly the larger power tip = less fuel because it restricts the total metering area b/t the jets and the rod? What secondary rods do you recomend assuming I have the "ED" ones in there now?

If I am bogging on transition into the secondaries It's either the secondaries are opening prematurly (possibly wind up spring adjustment) or not enough fuel at the higher RPM (secondary metering rods)? It seems like changing or bending the hanger can also effect the mixture, which is probably why Carlos had me bend my hanger. Nothing I read mentioned anything about inspecting the spark plugs at diffent RPM ranges to determine tuning. I would think that this would be a good method in a boat? My thought was to put in a brand new plug, run the engine at cruise for a couple of miles then inspect? That would tell me the primary side, then I could do the same for WOT. What do you think, would this work?

I wish I would have just saved my money and purchased an Eddlebrock 1409 with the metering rod kit designed for a 4.3L vortec, oh well live and learn.

While the 4.3L non-vortec has a richer 2ndary rod, you don't know how the rest of it was claibrated. Wind-up might have been sooner or latter, etc.

Try adj the wind up and 2ndary rods, those are the easiest to adjust. I think it is backwards from the normal approach to get the primary side 1st, but if it works, it will be less time.

Take the poster up on that book.

 

[kpiazzisi]

Re: What Throtle bracket to use 2bl to 4bl upgrade

please take a look at this plug and tell me what you think. Too rich or too lean?

http://i944.photobucket.com/albums/ad289/kpiazzisi/101_0718.jpg

thanks

 

[kpiazzisi]

Re: What Throtle bracket to use 2bl to 4bl upgrade

This is what my plugs look like. Is this rich or lean?

http://i944.photobucket.com/albums/ad289/kpiazzisi/101_0718.jpg

 

[John_S]

Re: What Throtle bracket to use 2bl to 4bl upgrade

This is what my plugs look like. Is this rich or lean?

http://i944.photobucket.com/albums/ad289/kpiazzisi/101_0718.jpg

If it was lean, that new plug wouldn't be that discolored. Maybe its just the picture, but the plug looks gray vs blackish. Unless you have something else going on, I'd say on the rich side.

How did you do the test? Was this running below the point of the air valve opening, ie cruise?

 

[kpiazzisi]

Re: What Throtle bracket to use 2bl to 4bl upgrade

I justed pulled one of the plugs that has been on the motor for the last few months. The last time we drove the boat we were at cruise for probably 20 minutes before shutting it down. At cruise I don't think the air valve is open. I spoke to Carlos today and he has agreed to rejet the primaries making them richer. I contacted "Cliff" the guy that another member recomemded, but he wants $175.00 just to tune the carb and he is backed up for 6 months. Carlos also said that they do have a couple of engines they can test the carb on, but normally they just test them on the flow bench so that they don't have to run fuel through the carb before shipping. I pulled the secondaries off and could not see any identifiable marking on them (maybe they were sanded off?). I did measure them with a Caliper and they were the same at .0565. This is also very close to the same size mercruiser used on the 4.3L. The boat actually runs pretty good except for the brief hesitation I mentioned. I just don't want to have engine damage from running it too lean. If the consensus from the photo is that the engine is not lean, then I probably will not worry about it.

 

[christoner2002]

Re: What Throtle bracket to use 2bl to 4bl upgrade

On mine, the lean spot was most noticable when coming off full throttle. If you just pulled the throttle back a little tiny bit, you would hear a faint popping. It sounds like Carlos is wanting to help. Glad to hear that. I hope he makes it right for you! Do you have another carb to run on it, while he is reworking yours? If not, let me know. I still have mine from my 5.7 here. If you wanted to borrow it, let me know. I hate to see anyone have their boat down for awhile this late in the season. Let me know!

 

[kpiazzisi]

Re: What Throtle bracket to use 2bl to 4bl upgrade

Eveyone on this forum has been so helpful, that I feel compelled to save readers from going through the nightmare of dealing with a Rochester Carb. In my opinion, don't bother. Throw it away. There are too many variables on a 4 bbl Rochester and way too many things that can be wrong. Way too many failure points. Also if you get a replacement or remanufactured Rochester, you have no idea what vehicle it came off of or how it was tunned. You also will have a difficult time finding a similiar application or someone who can tell you way size jets and rods to use. There are very old Carburetors used in the 70s to the 90s. When you buy a remanufacture carb, you are probably getting an automotive carb with a few tweaks to make it look like a marine carb. It could have cove off an old Pontiac 400 or a 6 cyclinder Covair for that matter. If you want to rack your brian trying to figure out if the wind up spring is adjusted right, if the primary metering area is too rich or too lean, If the secondary metering area is too rich or lean, if the 20 + year old ecentric cam is worn, if the secondary rod hangers are bent or not the best ones, etc. Just way too many variables. In my opinion you should bite the bullet and spend $300.00 for a 1409 and be done with it.

 

[Howard Sterndrive]

Re: What Throtle bracket to use 2bl to 4bl upgrade

bite the bullet and spend $300.00 for a 1409 and be done with it.

amen
I wish I knew of those bullets before I bought my i5 unit... here's the only Canadian online seller's price:

does the 1409 require an adapter to bolt to a stock cast iron manifold?

 

[kpiazzisi]

Re: What Throtle bracket to use 2bl to 4bl upgrade

I think this is what you need. It's only $13.99 at Jeggs


http://www.jegs.com/i/JEGS/555/15440/10002/-1