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Need large journal 327 build advice

  
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Need large journal 327 build advice

 
long_rod long_rod
New User | Posts: 19 | Joined: 07/13
Posted: 07/06/13
12:55 PM

Hi guys. This is my first post and I want to say hi to everybody and thanks in advance. I'm a novice engine builder but am smart enough to do lots of homework and ask for help from more knowledgeable people than me. I'm looking for some advice on building a pump gas Hydraulic roller 327. I have researched a lot of the 60's era builds but they were all 11:1 compression motors with solid cams (30 30 cams). I'm looking to get about 425 HP and even more important as much torque and mid range power that I can get out of this mighty mouse on pump gas (9.5:1 compression). This will be a 80% street vehicle (and yes before anyone says it, I know that I could get more power out of a 350 or 383 but everybody have those and i want something different. I have built a 350 but have always been interested in the mighty mouse 327's ...plus a 327, would be more correct to the truck it's going in) Here's what I have. I have a 1966 Chevy short-wide PU. It has a 12 bolt with 3.73 gears with a 700R4. I'm going to have about a 2000-2500 stall. I have a 68 327 block with forged crank that unfortunately will have to go to .060 over to be cleaned up. The block is at the machine shop as we talk getting bored, aligned honed, decked to .010, and balanced. I thought about going with a 6" rod but have decided to stay with 5.7's. To get my compression ratio right (about 9.5:1), I'll be using forged flat top pistons (probably Speed Pro brand) with Moly rings, machine shop owner is going to recondition some forged i beam connecting rods (he builds a lot of circle track cars and some customers replace them after one use but he guarantees that they are good). I will be using ARP rod and main bolts. Machine shop owner recommended following cam XE294 HR from Comp cams. it's duration at .050 is 242 (intake) and 248 (exhaust) with 110 degree lobe separation and valve lift of .54 (intake) and .562 (exhaust). I have always used hydraulic flat tappet cams but was told that a roller could take more duration. This will mainly be a street truck (no AC but possibly could have some day) so I don't want to accidentally put to much cam in it like a lot of people do. Does this cam look OK to you guys? As far as the heads, I'm looking at the Dar SHP, Aluminum, Assembled, 72cc Chamber, 200cc Intake Runner Cylinder Heads. They have 2.02 intake and 1.6 exhaust valves. (I don't know if I should go with a smaller intake runner size 185 cc or larger ones like the 200 cc or 215 cc. Can someone explain this too me? These heads are assembled but I will match springs to cam. I plan on using an Edelbrock Performer RPM Air Gap intake (1500 to 6500 rpm). I have two carburetors to choose from. I have a Holley 4150 750 Double Pumper or a 600 cfm Edelbrock. I'm thinking the Holley 750 might be best. Anyways, guys any and all advice would be appreciated. Thanks  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 07/06/13
09:20 PM

Sounds like you got your ducks in a row to me.

On the cam, that one is big but with your stall, deep first gear, and rear gears you might be okay. It'll want more rpm before it hits its sweet spot and that shouldn't be a problem because the 327s like to rev. Dropping 10* may be better suited to street use. A cam of given duration will act smaller in a 400cid motor than it will in a 300cid motor. That 242 cam would be large in  383, in a 327 it's going to be radical.

IMO the 185 heads would be better because the motor is smaller, relatively. The bigger the port volume in the heads, the more volume of air you have to get moving before you have velocity of movement. Then again if you plan on running it to 7500rpm regularly go with the 200cc heads.

On the carburetor, I have learned to use the AFBs and Holleys have near infinite tuning. If you plan on running it to 7500rpm, the 750 will better suit your combination.

CFM = (RPM x CID) / 3456
This formula does not consider volumetric efficiency.

CFM = (CID x RPM x VE) / 3456
This formula takes volumetric efficiency into consideration.

Most street engines do well to see more than 85% VE unless it's got forced induction. If you plan to keep it under 6500rpm and figure it at 85% VE the 600cfm AFB will do the trick.  
68scott385 68scott385 68scott385

long_rod long_rod
New User | Posts: 19 | Joined: 07/13
Posted: 07/06/13
11:47 PM

Thanks, That was what I was thinking too on the cam ...that it might be too big but I have never built a roller motor before. What packages/cam would anyone else recommend?  

long_rod long_rod
New User | Posts: 19 | Joined: 07/13
Posted: 07/06/13
11:49 PM

This is one of my favorite parts of a build. Figuring out what pieces you need and what you can afford. Need a new intake ...the wife didn't really need a new dress anyhow. Smile  

long_rod long_rod
New User | Posts: 19 | Joined: 07/13
Posted: 07/06/13
11:50 PM

Btw, that's the kind of advice I was looking for on the carb too. thx  

Dave632 Dave632
Addict | Posts: 2222 | Joined: 07/08
Posted: 07/07/13
07:37 PM

I agree on a smaller intake runner such as the 185. If this is a street car I would also go with a little smaller cam.
I ran an Isky solid roller 327 55 Chevy way back in the mid 60s when rollers were not so common. We would shift that motor at 8000, (stock vette forged pistons and rods), and occasionally at 8500. It had the valley kit in it so the lifters have their own springs to help control high rpm valve float.
By the way according to Reher and Morrison, who know a little about race engines, long rods are not that important. They found there is not much to be gained with them.  
[[SUPPORT AMERICAN CARS, STOMP A RICE CAR TODAY.]]

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 07/08/13
07:20 AM

all good advise.     sounds like a fun build.

  is this the kind of valley/rev kit you were talking about Dave?    i'd consider buying one if i had a roller cam.  
http://www.airflowresearch.com/index.php?cPath=75  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 07/08/13
08:46 AM

I believe that's what Dave is talking about.,. in the early days, they were called ultra rev kits.

http://www.iskycams.com/pdfcatalog/2004-05/page21.pdf

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Dave632 Dave632
Addict | Posts: 2222 | Joined: 07/08
Posted: 07/08/13
04:26 PM

That was it Joe/Tuff. Shows how far back I go. I was the first kid on the block with that setup back in 64. That was one screaming 55, set the track record for C gas at Flemington and Old Bridge,(now Englishtown), then, had a lot of fun with it. I ran the Isky 505 roller cam back when a .505 lift was a big thing.  
[[SUPPORT AMERICAN CARS, STOMP A RICE CAR TODAY.]]

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 07/08/13
06:08 PM

Chuckles.,. I went 1 crazier than that with a 550 Super Legerra, but, I was running my 327 (chevy powered) Jeep in the unlimited class against BB's.,. I would launch just under 7000 off the boards in second low range, to turn the big paddle tires.,. deceleration was at 9500+,,,,, before the trees came into view.
It was like running on marbles.,. pretty scary, thinking back.

1) Isky '505C' roller cam

Lift at valves .505" (adv gross using 1.6:1 ratio rockers)
Adv duration 320*
Duration at .050" 274*
Lobe seperatin 110*
Intake timing 50-90
Exhaust timing 90-50
Valve lash hot .028"

2) Isky 550 Super Legerra, grind #RR-550, type 'Ultra Super Track'

Lift at valves .576" ( using 1.6:1 ratio rockers)
Lift at cam .360"
Duration 330*
Lobe seperation 108*(this is not good)
Intake timing 57-93
Exhaust timing 93-57
Overlap 114*
Valve lash .018" hot
(above timing given at .028" lifter rise)

(following timing given at .050" lifter rise)

Duration 282
Intake timing 33-69
Exhaust timing 69-33

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Dave632 Dave632
Addict | Posts: 2222 | Joined: 07/08
Posted: 07/08/13
07:18 PM

That's great Tuff.
The Super Legerra came out after I bought my 505. I remember it well and it's nice to go down memory lane like this. Don't we wish we could go back in time an relive those days. Sure were some great times. I tell my son about them and he is in envy of what went on then.  
[[SUPPORT AMERICAN CARS, STOMP A RICE CAR TODAY.]]

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 07/08/13
08:46 PM

We are reliving those days, as we pass our hard earned knowledge on to others.,. what we are doing is not bench racing.,. simply passing on knowledge, from the past.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

long_rod long_rod
New User | Posts: 19 | Joined: 07/13
Posted: 07/25/13
08:05 PM

OK, I've changed my build up some. Let me know what you guys think of this combination and please offer ant suggestions you might have. I am now going with a hydraulic flat tappet instead of roller (couldn't justify hp gain to cost). I chose the Comp Cams XE 274 (230 intake and 236 exhaust @.050). I'm going to put some Brodix IK 180 aluminum cylinder heads (70 cc and 180 intake runners)with some mild porting and polishing. I'm also going to use a gasket matched Brodix HP 1 intake manifold with a Holley DP 750 on top. I was told that I'm probably gonna need to put smaller jets in. I'm using Speed Pro forged Aluminum flat-tops (+5.4 cc) pistons and had my block decked to .010. If my figures are right using a .041 head gasket, this will give me about a 9:5:1 compression ratio. I'm hoping that this combination will get me about 425 hp and about 400 ft lbs of torque. The block and rotating assembly is at the machine shop getting balanced and final hone. It won't be long before I can start building this mighty mouse. I'm so excited I can't hardly stand it. I love hearing a motor come to life!!!  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 07/26/13
07:21 AM

http://www.kb-silvolite.com/calc.php?action=comp

Here's a link to an on-line compression ratio calculator. IMO it's a good place to check the math and verify what you get otherwise. You can even figure dynamic compression with this calculator.  
68scott385 68scott385 68scott385

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 07/26/13
02:37 PM

i kinda think your compression might be lower than you think? Confused    the 70cc heads and .041 head gasket might not be the best combo?
   i ran it on summits compression calculater and got 8.882.
http://www.summitracing.com/expertadviceandnews/calcsandtools/compression-calculator

 with 64cc heads i got 9.4.

 i could be wrong though.   wouldnt be the first time, lol.  

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