Offenhauser 2@ !bbl Holley swap info

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Syleng1

Syleng1

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Quick question:

Has any one here done the offenhauser 2@ 1bbl Holley intake conversion? I just bought the whole set up including brand new carbs in the packages (Holley 1920) and the linkage set. I am looking for another 1bbl unsilenced air cleaner if some one in or around Connecticut has one for sale I need one. I'm just looking to kinda get a heads up on what to watchout for with this (laughing) high hp bolt on item.

Also looking at a new cam - any ideas on who but Comp cams makes Slant six camshafts?
I'm thinking a 800rpm - 4500 rpm range like 270 duration and no more than .420" lift. I still have the stock gears of 2.76 in a 7.250 rear. I am not looking for a huge lift just a bit more than stock. I have heard too high a lift / duration in a /6 and they sound like a air popcorn maker.

Thanks,
Joe
 
I sent my stock cam to Oregon Cam for re-grinding. $75 + shipping. Ken (800-539-9165) recommended two:
He says the most popular for what I am doing is their #819. 219/219 @ .050, 264/264 adv. .437/.437 lift, 110 lobe sep.
#818 212/212 @ .050, 256/256 adv. .431/.431 lift, 110 lobe sep.

I went with the milder #818. Comparing it to the 2 cams listed by Comp the RPM range should be idle-4500.

My 225 has a 4.12 stroke and I don't foresee any high RPM's in my future.
225, new bore .040 Silv-o-lites, .080 off the head with hardened seats and new guides, 3 speed manual. I'm gonna fab a 2-1/4 or 2-1/2 exhaust. No results so far as it's not assembled yet.

This car (64 Val) is going to be a driver. I'll keep my eyes open for an intake, headers. or Dutra duals but for right now I just want to get it on the road. Also the turbo guys have me thinking.

View attachment P1160208.jpg
 
Try Clifford performance. I just got my headers and a new dual 2 barrel weber carb set up from them. They have a cam for the slant and when you call ask for Larry. He's a great guy.
 
KosmicKuda said:
I sent my stock cam to Oregon Cam for re-grinding. $75 + shipping. Ken (800-539-9165) recommended two:
He says the most popular for what I am doing is their #819. 219/219 @ .050, 264/264 adv. .437/.437 lift, 110 lobe sep.
#818 212/212 @ .050, 256/256 adv. .431/.431 lift, 110 lobe sep.

I went with the milder #818. Comparing it to the 2 cams listed by Comp the RPM range should be idle-4500.

My 225 has a 4.12 stroke and I don't foresee any high RPM's in my future.
225, new bore .040 Silv-o-lites, .080 off the head with hardened seats and new guides, 3 speed manual. I'm gonna fab a 2-1/4 or 2-1/2 exhaust. No results so far as it's not assembled yet.

This car (64 Val) is going to be a driver. I'll keep my eyes open for an intake, headers. or Dutra duals but for right now I just want to get it on the road. Also the turbo guys have me thinking.
Click to expand...

you might look into Waggins dual setup. I've just got mine and I think "memike" has a set already on his car. I had Waggin make mine so that they pointed straight out towards the inner fender up close to the bottom of the intake manifold since I am later going to turbo the /6.(ie. really short 2 into 1 big pipe or 2.25 or 2.5 for the extra flow to the turbo) they were not that expensive either if I remember correctly.

here are a couple of pic's I snagged from his setup

View attachment duals.jpg

View attachment dual intake and exhaust.jpg

View attachment two for two.jpg
 
MvJackson said:
Try Clifford performance. I just got my headers and a new dual 2 barrel weber carb set up from them. They have a cam for the slant and when you call ask for Larry. He's a great guy.
Click to expand...

DON'T GO CLIFFORD! Great, I'm glad you didn't get ripped (at least not yet that you can tell) but just about everyone else in the past 5 years or so has. Maybe even longer than that. Not to mention, I guarantee they don't have even close to the selection of cams that OGC does.

I've yet to hear anything bad about Oregon Cam Grinders, I used them a couple of years ago and they was very helpful and reasonable, sounds like the prices are still good. If I were you, I'd have the cam and lifters reground by them. The 818 and 819 cams are very wonderful, especially for milder slants. I'd say the 818 would be just what you're looking for, I hear it comes on just off idle.

Erson used to have a few cams, I dunno if they still do anymore. I think they went out a few years back? But I see their back again, unsure if they have any of the old custom grinds by Dutras (RV10 and RV15)

I'm pretty sure lift don't have much to do with how a motor 'sounds', and I guarantee I've had my slant compared to a lot of things, and 'air popper' ain't one of 'em! :wack:
I have the 819 ground at a 109 LSA (would have a little more chop than the standard one) and with dual exhaust it'll lope a little bit. That is if you idle it down to 600rpm... The 818 with a 110 wouldn't lope at all I imagine, especially with single exhaust (recommended)

If you go over to the slantsix.org forum, in the Engine FAQ they have a list of the different cams offered by OCG. Most of the folks use them over there, and for good reason.
 
MvJackson said:
Try Clifford performance. I just got my headers and a new dual 2 barrel weber carb set up from them. They have a cam for the slant and when you call ask for Larry. He's a great guy.
Click to expand...

Have you got that running yet? I recognize your name from instagram.


Jake
 
Nothing wrong with Comp, their nitride coating is the option that you DONT want, it makes the camshaft oil pump drive gear harder than the pumps that can cause wear. But its only an OPTION. One of those "it happened to a friend of mines friend" story that has very shallow roots. Just trying to pass on some solid info, you decide.
 
pishta said:
Nothing wrong with Comp, their nitride coating is the option that you DONT want, it makes the camshaft oil pump drive gear harder than the pumps that can cause wear. But its only an OPTION. One of those "it happened to a friend of mines friend" story that has very shallow roots. Just trying to pass on some solid info, you decide.
Click to expand...

I do apologize. I knew it was something about the coating, but did not know it was an option. Thank you for correcting me on such. I couldn't figure out how the slant guys had problems but none of the v8 guys did. Again, thank you for clarifying and sorry for not having the whole story.
 
Joe
I have that exact set-up on my '64 Dart. I installed it several years ago with a set of 'Dutra Duals' exhaust manifolds. The carbs are match Holley 1920's (even added a glass bowl for the rear carb).
You will have to re-jet the carbs (if I remember correctly, I dropped tree sizes).
A couple of modifications I made was to mount the control rods aluminum stock, using the holes in the manifold as mounting bosses. This provided clearance from the center intake/exhaust manifold mounting bolt. I did the same at the rear for the throttle rod (didn't like the angle when it was mounted to the intake).
Use the threaded hole in the intake to plumb your PCV.
I also used a shorter air filter on the front carb due to hood clearance issues.
Plumb your fuel lines away from any heat source as it will boil today's 'modern' fuel.
I also added cruise control which works quite well.
As far as cams, I used a Comp grind from a stock early seventies A body, but that all depends on what your plans are. Mine is strictly a cruiser.
The set up works well with the only aggravation being off idle accleration. It took a while and a lot of distributor tweaking to get it worked out.
If your going to the Mopar Nationals this year, I'll have the Dart there.

Omni

I
 
Well, I guess most don't run the dual 1 bbl intake from Offy. I want it just to be different. I'm running a stock exhaust manifold with the Accurate Exhaust 2.250" set up with the higher flow "D" muffle to look factory but better flow. I picked up 450 rpm from the smaller factory exhaust. They do a super job with factory looking exhaust.
My engine is a 66' with the head done for hardened valve seats and viton valve seals. The lower half is all rebuilt to stock. The engine has about 4-5k on it since the rebuild and runs good. This is why I am doing the mods now. /i just want a bit more cam for better breathing.

Side note: really tall lift and high cam lobe separation cause the "air popper" effect. I heard this in a slant in a Barracuda that ran high 10's in the quarter with no nitrous or turbos... back in the day. Boy did that catch your attention.

I'm just not finding alot of cam selections out there and the oil pump drive gear getting worn out kinda does bother me. Easy to change but who wants too.
Joe
 
64' DART:

Thank you for the advice... All good advice. I own a welding and equipment repair company so fabrication is right up my alley. I have a tendency to buy vs make because it is quicker not cause I am lazy. We are slammed at the shop and very little time to play.
Joe
 
I have a twin single Offy manifold that eventually I will play with. I ordered a pair of carbs from Langdon's Stovebolt http://www.langdonsstovebolt.com/store/#!/Carter-Weber-Carburetor/p/1222026 and will give them a try. I will need to open up the manifold so these carbs will fit. This project is low priority as my main priority is to assembly my 65 slant to go back in my wagon. It's been decked 90 thou with the head cut 10 thou; overbored 30 thou, O.S stainless steel valves, exhaust hardened seats with 340 valve springs installed after the head had some port work done to it. I had Oregon do my original cam to their 346 grind - 234/228 at .050 (which equates to 476/479 lift) - their turn time was less than 2 weeks from time I shipped it to them to when I received it back. I am using the original matching oil pump. Will be working with a set of triple SUs and might go with a set of triple Webers later. The twin Offy I'll probably be using on another slant
 

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Let me say first I'm an amateur at all this , I am looking for some advise about the offenhauser 2@ 1bbl Holley 1920 set up also. my 65 valiant 225/ was bored .40 over with a mild cam , has the offy , 2 holly 1920's , and headers. this is what I have receipts for from 1 of the previous owners. They took off the factory fuel pump and added this electric one on top shock mount. Soooo I'm having issues with the pump quitting after 10 minutes of running , and then It will work again after a 5 min. sit.

Should I go back to the factor pump ? Will one still work off the cam that was changed out ( don't know any specs on it ) And if so will the manual pump satisfy the 2 holly's? Not looking to race , just like the look under the hood of the 2 carbs , plan on cruise nights driving only.
 

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MvJackson said:
Try Clifford performance. I just got my headers and a new dual 2 barrel weber carb set up from them. They have a cam for the slant and when you call ask for Larry. He's a great guy.
Click to expand...

check this guys setup on i.g. it came out really good post another better vid!!
-kevin (kemo73)
 
Well, It is update time! I will try to get pictures on board when I get them off my I-pad.

The dual 1920's were a bear to get sync'd. I totally agree with '64DART that the throttle rods do not line up and you really need to take the time to properly tweek the rods AND the linkages. Making sure both carbs are open fully at the same time and are closed at the same time was key. I actually made my own tabs and welded them on the carbs for the throttle linkages to match up. I made my own dual return spring set up as well.
Once it was dialed in pretty good and I was able to torque stand the old Barracuda for the first time since I've owned it (bought her in 1989)

I had a really tough time with the intake / exhaust head studs breaking off- both taking it apart and putting it back together... I tried to torque them and before I reached the inch lbs of torque in the FSM the studs broke.. I replaced all the studs. MENTAL NOTE: If they are almost 50 years old... change them!
These are the head studs not the intake to exhaust studs.

So after the car was running pretty good, I switched over the distributor to a new electronic distributor, Added the HEI 4 pin module from MSD with the matching Blaster II coil from MSD. I upgraded the spark plugs to NGK and the gap to 0.045" (My cap and rotor was good and 8mm wires were recently installed.) I fired her up and adjusted the timing and the car still has a slight hick-up (some carb adjustment on the idle air mixture screw helped this lean miss at idle) and this all in a few hours. I had so much power I spun both tires and layed down black marks. It may not seem like much when my 72' 340 Demon will blacken the road with ease thru all 4 gears but I was so excited my little slant six in the 66 Cuda will now too.

Here's all I got for a recap: 66' 225/6 65,000miles
Cylinder head was shaved 0.010" fresh valve job, Vinton seals, hardened valve seats ports cleaned up and gasket matched to intake.
Stock 66' compression
Hi volume oil pump -Melling
Offenhauser 2@ 1bbl intake
2@ Holley 1920 carbs
Stock exhaust manifold - Accurate Exhaust 2.250" exhaust system
Electronic distributor with HEI conversion.
Stock 904 with RV shift kit
Stock rear with 2.76? Gearing and 26" tall tires
Lot's of love.
 
Early pic of complete set up. Need to install air cleaners and re plumb the fuel lines.
This inter the whole drive train is coming out for a repaint an clean up. 49 years... she is due for a face lift. Thank you for all the help. Now that I know what is needed, if you want help on your offy / 2@ 1920 Holley set up, pm me, I'd be glad to help.
Joe
 

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That's awesome that you got it running pretty well! The mental image of black tire marks got me LOL. You should race it on over to Carlisle or the Nats so we can see it!

I have a 64 Val 225. Engine is still apart. Bored, milled, ported, cammed.
Yes I have a spare 340, No I'm not going to swap it in because I wanted a slanty.
 
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Here is the pic with the chrome air cleaner and the dirty sweaty one from Tony's Parts for $69.00 delivered.
Even though they are both slant 6 air cleaners from 64-66 a-body... The rear is smaller diameter (same air filter) so i am thinking the rear is actually older than the front.
Thanks for all your support. Test drive was very good. Burn out with ease. Also not seen was the HEI 4 pin conversion. Runs better and starts better. Any questions please shoot me a pm.
Joe
 
Hi guys , I,m still playing around with this set up , I have 55 jets in both holley's , was wandering if they were too big ? what are you guys using?
 
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