#'s Matching 340 build

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You guys are good and better than me.

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Is it any wonder--the 340 is so vaunted? J.Rob
I wonder what it's gonna do through the cast iron manifolds? Did you use a cam with that in mind? I'm not competent on cam selection, or anything else engine related for that matter. LOL. I did see what you used.
 
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I wonder what it's gonna do through the cast iron manifolds? Did you use a cam with that in mind? I'm not competent on cam selection, or anything else engine related for that matter. LOL. I did see what you used.

Probably 25-40hp loss through the exhaust manifolds--Yes I chose that cam with the manifolds in mind--take a look at the specs I posted-you should be able to see it. J.Rob
 
Balance will be cheaper based on removing weight and not adding mallory.
If the guy grinding is good, the machine is serviced, and he gets them done quick...he can make plenty of money doing them at 90 ea. That's magd.
I used to have beans do them, 120.00 with acl bearings... Jesse was the grinder but he went on to rep for clevite/maul and makes way more money than he did grinding. The place was sold/obsorbed by the nextdoor shop and the prices went up..and we all took our **** to Rick's in santee or mesa in escondido who have been in biz there since 1946. there .machine tech,mjm, total per'ford'nce, JBA, a ton of places... but they either over charge and dont call or advice to what they do...or they are just young guys with heads/egos bigger than their brand new machines. People set records with old stuff most still cant touch today... and certainly most of the weekend warriors cant hold candle to.

I’m just catching up on this thread but a guy who charges $90 around here will starve and close. To get a crank done well here (and I know the best guy around here) is a $300 proposition. That’s not stroke corrected and indexed... that’s cleaned, nagged, turned, and polished. Nothing fancy.

In regard to PRHs comments on streetable power- I’m with him. I consider how often the engine will be in an rpm range for a street car with mild gearing. The car willidle and be under 4K for the vast, VAST majority of its life do power over 5k in not a concern. I think this gets way over-thought by many these days.
 
I loved the cam choice btw. It did well, but I think it will show lower in the chassis with an alternator, water pump, and full exhaust on it. I’d say it will perform a little better than the stock 275 rating, which is really what he wanted from the sound of it.
 
I’m just catching up on this thread but a guy who charges $90 around here will starve and close. To get a crank done well here (and I know the best guy around here) is a $300 proposition. That’s not stroke corrected and indexed... that’s cleaned, nagged, turned, and polished. Nothing fancy.

In regard to PRHs comments on streetable power- I’m with him. I consider how often the engine will be in an rpm range for a street car with mild gearing. The car willidle and be under 4K for the vast, VAST majority of its life do power over 5k in not a concern. I think this gets way over-thought by many these days.

Totally agree Moper, I charge $280 CDN for exactly what you describe. The crank in this 340 is .020"/.020" now. Balancing was handled internally of course and that is an additional $380 CDN. J.Rob
 
I loved the cam choice btw. It did well, but I think it will show lower in the chassis with an alternator, water pump, and full exhaust on it. I’d say it will perform a little better than the stock 275 rating, which is really what he wanted from the sound of it.

Of course it will be lower in the actual chassis, I bet it will feel much stronger than before. J.Rob
 
I’m sure it will. He’ll be happy, which is the real success. Dyno numbers are just conversation.
 
those are really good numbers , you're using a smaller cam than i thought , customer should be real pleased with the engine in the car it will pull nicely , what carburetor will you be using
 
390 hp 410tq
Needed more cam for that.
My stock x head 280 dur .528 solid .030 340 did 392hp with a self driven water pump,ps, 1 5/8 and through full 2 1/2 pipes.
It's nice to see the small cams Dyno tested/used . I'm not so excited about them as other people are, but I think these other people are the people who would more so use this type of Cam.. and so it's more interesting/gives an idea of their power level.
Thanks for sharing
 
I thought the owner wanted a stock rebuild? Where is the carter carb? What are the numbers with the correct carb?
Thanks
Great thread btw
 
I thought the owner wanted a stock rebuild? Where is the carter carb? What are the numbers with the correct carb?
Thanks
Great thread btw

Patience, I only used the Holley for the critical break in as I know it is a good carb. This afternoon, on goes the Carter and the original distributor. J.Rob
 
Patience, I only used the Holley for the critical break in as I know it is a good carb. This afternoon, on goes the Carter and the original distributor. J.Rob
I didn't see it mentioned but what valve spring are you running with that cam? Comp's catalog recommends 622-16 but that part # is for a lash cap LOL!
 
Hey RAMM, I just looked through this thread and I didn’t see what pistons you ended up with and the CR. I did see you were looking at some JE flattops, but that was all I found.

TIA
 
Hey RAMM, I just looked through this thread and I didn’t see what pistons you ended up with and the CR. I did see you were looking at some JE flattops, but that was all I found.

TIA

JE piston 310725 was used. Cranking compression is 170psi. J.Rob
 
I didn't see it mentioned but what valve spring are you running with that cam? Comp's catalog recommends 622-16 but that part # is for a lash cap LOL!

Using a Comp 901-16 Spring / 10* retainer and lock package. It buzzes to 6000 rpm effortlessly. J.Rob
 
I didn't get to the Carter carb yesterday. I did spend some time perfecting the dyno exhaust system and I installed a new dual wideband O2 sensor system. It works perfectly. What's even more interesting and impressive is I was able to compare the AFR readings from the dual wideband to the Superflow air turbine/fuel turbine calculated AFR readings. The average AFR from the widebands was 12.4 and the average AFR from the Superflow calc'd AFR was 12.3. I'd call that a win all the way around. Where the Superflow system lacks is at idle-you can't trust the AFR reading--with the dual widebands I was able to get the carb dialed to a steady 14..5-14.7 idle AFR on both banks. Exhaust temp readings with a IR gun we within 80 degrees on all tubes as well in the high 700's. I think Mopar knew what they were doing when they designed this intake manifold. I'm impressed. J.Rob
 
Ever hear of issues with Comps locks/retainers?
Nope--just their lifters and noisy lobe profiles. I won't run their XE series anything or use any of their lifters. I do like some of their springs, and cams and I do use them for custom grinds as I like their lobe catalog and quick turnaround. I also like their nitriding option and use it on all solid flat tappet customs. J.Rob
 
Excellent thread, I really appreciate the information and results being shared, my hats off to you sir!
 
[lQUOTE="RAMM, post: 1973147393, member: 17675"]I think Mopar knew what they were doing when they designed this intake manifold. I'm impressed. J.Rob[/QUOTE]
It would be interesting to see if the RPM Air Gap intake would show any hp gains on a build of this type and if those gains would justify the expense over iron intakes.
 
'69. J.Rob
if you had a choice which manifold of these 2 would you use for getting the best power and fuel mileage ? fully ported air gap or a stock 1970 iron manifold . interested because i'm building a numbers matching 340 for my car . had enough of the go fast crap , just want a reliable engine for my 100mile+ daily drives .
thanks
 
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