Inliners International Forums General Discussion MOPAR Newbie with High Performance Questions!

I posted this over on P15-D24 but know I should also put it here! I have lurked on this board on and off over the years and only recently registered. I remember reading the posts about Ball and Ball woes, and Oiling modifications back when they were ongoing and growing day by day. I need to go back and re-read all of that good info and hopefully add some of my own to the mix.

Anyway here is my post, hope you guys can help! -

Hey Guys! I'm working on building a 1951 Dodge 1/2 ton with a bit of a hot rod engine ( I can't leave ANYTHING stock... its my weakness...) I have a 265 industrial engine I scavanged out of an Oliver combine. Well I actually bought the combine just for the engine. Best $100 bucks I have ever spent. I have a good chunk of the engine rebuild well under control, but I have a couple of questions.

Valve springs.... I want the option to open this engine up when i feel like it (And I do mean OPEN it up and let er eat!). I would like to be able to NOT float the valves when doing so. I would like to make sure that I am good to 6000 RPMs. That will give me a little bit of a safety factor for what i really want to run as well as give me the option to use the engine in a different application down the road if I decide I don't care for it in the truck.

Carbs. What do the stock single barrel Ball and Ball (Carter) flow CFM wise? What about the single barrel Strombergs like the BXVD-3 that was found on some of the Dodge trucks? I have my heart set on a progressive linkage triple carb setup and plan on making it very responsive even if I need to spend some dough to get the carbs that will make it work the best. Spending less money is always a good thing though and i have some Ball and Balls and Strombergs BXVD-3s kicking around the shop. Holding myself to a vintage looking triple setup though I am sure that triple 81s will flow exactly what I want.....

Camshaft - Where can I get ahold of a regrinder that knows these engines and can give me a great grind for my app?

HEI system - Where can I got to get a good conversion, or better yet is the a DIY guide for building one out of commonly available parts?

Oil System - know that some if not all of these motors had a bypass oil filtration system. How is this system set up and how can I make it either a full flow system, or ensure that the bypass system actually is set up and works correctly?

That should do it for now

Thanks guys!

Jason

though my full race 230 is severely intake limited right now, and as such will only spin to 5200rpm, I can help you with the mechanical part of your 6000rpm question....my engine uses the middle spring out of a triple spring set from Scneider, used, out of a small block Chevy sprint car engine. Approximately double the installed seat pressure of a worn out stocker.

Cross drilled crank is a must for high rpm use

you need to speak with Earl Edgerton and George Asche, they can guide you on cam and carb selection.

Langdons has an HEI for the small Mopar, I bet he can fix you up for the 265, or, you can build your own using a combo of GM HEI and Mopar parts

Not sure on the full pressure filtering, I have no filter on my race engine.

I have been going back and reading some the old performance threads Lots of good ideas and direction posted in some of them threads. I even took note on one of Hudson's threads about heat dissipation being a major limiting factor to HP. I knew I held on to that old oil to water cooler designed to be installed in the radiator hosing off of an old 354 Perkins for a reason!

Jason

To answer you about the Stromberg Carbs. These carbs were used on the trucks with a fluid drive unit. The Stromberg had an internal dashpot that was needed with the fluid dirve.

HEI 6 volt positive ground is going to be a nightmare. Go 12 volt negative ground and you will have more options.

Full Flow filtration on the big block is fairly easy as I remember. There was a thread a while back on the p15-d24 website that involved dropping the pan and installing a plug in the return channel of pressure control system.

6000 rpm on these long stroke motors. Won't say it can't be done but not something I would try.

6000 rpm can be done, but most likely there will be no advantage in doing so. It's been discussed here before, and is well worth the read, but piston speed is what'll getcha. If you exceed the critical speed of your piston's material- it comes apart. Also, you might spin to 6k, but horsepower and torque will taper off before you get there. Right now my engine makes peak HP @ 4250 rpm, and holds at 5200. After I correct my intake airflow issues I too hope to be capable of 6000 rpm, but I betcha my peak HP is still under 5000.

6,000 RPM = 4,750 f/m piston speed.
Hope you're planning on Venolias.

I think HRT doesn't plan to run the engine to 6000... but wants it safe to that level...

I also think, it being a flathead, that he's worrying about something he shouldn't and will rob himself of power and valvetrain durability if he goes too far down that path.

Long stroke engines lose power with revs because of mechanical stresses, that's why horsepower levels will be at lower rpms.

I disagree - Harley engines with that stroke have been raced for 50 years. The stock Chief 80 is 4-13/16".
They break, but they run pretty well until then. The limit (other than the strength of the pieces) is rod ratio and breathing.
Since valve-to-piston contact isn't possible, valve float does very little damage unless you persist in running like that.
I wouldn't base the spring rate on that factor, especially since (with the same valve train dynamics) the spring for 6,000 RPM is 41% higher than 5,053 RPM (4,000 f/m, which may still be above where your power curve ends).
E.g. if you need 250 lbs. open pressure for 5,053 RPM you need 353 lbs. for 6,000 RPM.

How big are the valves, what does the chamber look like, drawing of the port X-section?

I'll repeat what was considered good info 50 years ago:
2 carbs are a big help, better mixture distribution than stock + more power and almost no loss of response (if carb size is small).
3 carbs only add a small amount of power and only with a cam and exhaust change, reduce response, and may have worse distribution than stock using progressive linkage. Straight linkage cures the dist. problem, but makes response and mileage very sensitive.
If you're comparing manifolds by appearance you're making a mistake.
You could run 3 × 1 bbl. side draft like the Corvette if you have room.