What cam are you running?

[LTOP]

The exhaust side is where the help is needed bud. Look at the ports.

Exhaust valves and ports need only be 3/4 of intake size. It is much easier to empty a chamber by pushing out than it is to fill it by sucking in through a carb and a manifold.

Even though this is my first slant engine, I am a big believer in porting. When you think about it, people pay big bucks to get a valve only .14 larger when they switch from 1.88 to 2.02 valves. 1.88s are smog dog heads and 2.02s are performance heads. Yet the difference is only .14. Now look at the bowls under your valves on a stock Mopar; completely choked up. You can open them up .25 or more. Frankly, I would take a properly ported 1.88 head over an unported stock 2.02 head any day, and have in the past.

Then look at the lousy port shapes and surfaces in the stock heads, especially back in the 60s and 70s. Its like no two are the same. One of the reasons modern engines blow away older engines is not just fuel injection and turbo charging. The quality of machine work and the shapes of the runners are far superior.

Compare a new aftermarket SB head with an old stock one. No contest. The difference is in the ports.
I would never build a performance engine without porting the heads.

 

[RustyRatRod]

Not gonna get into a pissin match about it. This is something that's been documented to hell and back on the slant. That's the whole purpose behind Frank designing that reverse grind camshaft. Yall forgotten Frank already? He's not stupid, you know? I love when people just start makin stuff up to argue. Frank's been there and done it. Ed, you of all people should know that.

 

[Woods74]

^x2.

Thanks Kuda! ;)

 

[805moparkid]

Not gonna get into a pissin match about it. This is something that's been documented to hell and back on the slant. That's the whole purpose behind Frank designing that reverse grind camshaft. Yall forgotten Frank already? He's not stupid, you know? I love when people just start makin stuff up to argue. Frank's been there and done it. Ed, you of all people should know that.

ive actually never seen any info that cam on here or .org. If you have a link i would love to read it.

 

[RustyRatRod]

Maybe Charlie can help. I was wrong about Frank designing it. Doug did. I couldn't find the exact specs on it over there, but there's several threads about in general where you were participating. I THINK the one I am talking about was like a 280/270 or 290/270 grind. I cannot remember.

 

[MoparChic71]

My head and intake manifold are ported and polished. It was one of the first things I thought about doing.

 

[805moparkid]

Maybe Charlie can help. I was wrong about Frank designing it. Doug did. I couldn't find the exact specs on it over there, but there's several threads about in general where you were participating. I THINK the one I am talking about was like a 280/270 or 290/270 grind. I cannot remember.

I thought it was a reverse grind the other way. and im sure I did, I just don't remember

My head and intake manifold are ported and polished. It was one of the first things I thought about doing.

What intake and are you sure the "polished" the intakes or just smoothed them with a sand roll

 

[RustyRatRod]

no, that wouldn't be reverse grind. Normally, the exhaust has more duration. the reverse grind is the reverse of normal. ....and I was mistaken when I said the exhaust needed the help. Forgive me. I have had maybe 10 hours sleep in the past week total.

 

[805moparkid]

no, that wouldn't be reverse grind. Normally, the exhaust has more duration. the reverse grind is the reverse of normal. ....and I was mistaken when I said the exhaust needed the help. Forgive me. I have had maybe 10 hours sleep in the past week total.

no big rusty :coffee2::coffee2:

 

[MoparChic71]

What intake and are you sure the "polished" the intakes or just smoothed them with a sand roll

The head and intake manifold are gasket matched, ported and polished. The guides under the valves are blended. I had help but did most of it myself. I used various fine grit wetsanding paper and the felt roll tips for a dremel with some valve lapping compound to polish all of it. I had other buffing tools for when I do my finger nails I was thinking about polishing the combustion chamber also but haven't got to it yet. It takes all day for it to shine.

 

[805moparkid]

thats more than enough for what your doing, your not going to hurt it as far as you have gone.

 

[MoparChic71]

What kind of horsepower would I be looking at with the stuff I've done and saying with a decent cam? 805moparkid do you know your hp or just times?

 

[805moparkid]

What kind of horsepower would I be looking at with the stuff I've done and saying with a decent cam? 805moparkid do you know your hp or just times?

my car dyno'd at 200hp (wheel) before i tuned it, i think i was running a 15.1 when i had to dyno'd and im down to a 14.25. Now not all that is tuning but probably 3 or 4 tenths are... I have either forgotten or didn't see anything about bore, compression, what valves you have, or intake/exh

 

[MoparChic71]

I'm going to reuse the pistons. The cylinder walls look good so just going to hone them. The engine only had 42k original miles so everything looked pretty decent. I was thinking of going 30 over but that would lower compression I guess. I have the 1.70 1.44 stainless valves head milled .090. 4bbl intake with a holley 390. By what I've read online just milling the head .090 and using the factory steel gasket will bring the compression up to 9.5 to 1. You run a good time for a slant what's does the car weigh? (Mine is 2900lb)

 

[805moparkid]

I'm going to reuse the pistons. The cylinder walls look good so just going to hone them. The engine only had 42k original miles so everything looked pretty decent. I was thinking of going 30 over but that would lower compression I guess. I have the 1.70 1.44 stainless valves head milled .090. 4bbl intake with a holley 390. By what I've read online just milling the head .090 and using the factory steel gasket will bring the compression up to 9.5 to 1. You run a good time for a slant what's does the car weigh? (Mine is 2900lb)

well it may be 9.5:1 but ive seen the piston to deck height's vary from .140 about .200 so compression based off head milling is impossible at best. BUT IF it is a 9.5:1 motor and the head was done well you should be a good 125-140hp i would bet. No matter what the number is its going to be MILES better than what it was.

My 68 weighs in a 2850 w/o me last time i scaled it but ive been working on trimming the fat so i couldn't tell you. That said 2775 would probably be about right w/o ballast, race weight is 3200

 

[RustyRatRod]

Boring actually raises compression, but a minute amount. The over sized piston adds more volume to the piston head and increases compression......as long as they are the same style piston head and compression distance as the old ones.

 

[805moparkid]

Boring actually raises compression, but a minute amount. The over sized piston adds more volume to the piston head and increases compression......as long as they are the same style piston head and compression distance as the old ones.

on those stock cast speedpro's the lower the comp height a little to keep stock compression. at least the set i got did lol

 

[chongo25]

Might be a dumb question but where do you shop for a cam? I'm been looking for w better cam since I'm upgrading to a4 barrel intake.

Posted via Topify on Android

 

[805moparkid]

Might be a dumb question but where do you shop for a cam? I'm been looking for w better cam since I'm upgrading to a4 barrel intake.

Posted via Topify on Android

Oregon Cam Grinders OCG
Sig Erson
Howards
Schneider in CA
Crower

im sure others will grind for you

 

[chongo25]

Great I'll check them out.

Posted via Topify on Android

 

[cjh]

I got an Erson cam....the biggest off the shelf one....I haven't built the engine yet.

 

[MoparChic71]

I got an Erson cam....the biggest off the shelf one....I haven't built the engine yet.

how much was the cam and what are the specs? (Just curious cuz I started this thread to figure out my cam

 

[cjh]

how much was the cam and what are the specs? (Just curious cuz I started this thread to figure out my cam

Well.....the cam was about $100 cheaper to get it from the US than it was to get it here.....oh, and I got valve springs and solid followers too, in that price.
Here's a pic of the spec sheet that came with the cam.
I will be fitting bigger valves, and the head is already ported, polished, and had about o.140" taken off it.
I will be using it for drag racing.....not a street car.

This is my build thread.......................

http://www.forabodiesonly.com/mopar/showthread.php?t=109485

 

[805moparkid]

i cant read a single thing on that sheet

 

[cjh]

i cant read a single thing on that sheet

Your right......on another forum I'm on, you can click on the pic, and it goes bigger.......hhhmmmmmm.

108* LSA
Inlet 35-71
Ex 40-76
Overlap is 75*

0.340" Lobe lift for both.

Duration @ 0.050" is In 242* and Ex 246*

Tappets set @ 0.022" Hot.