HELP, will this 350 top end build work?

[rrl692000]

Looking to have nice daily driver, mostly in small town, so wanting torque and horse power in the lower RPM range on 87/89 octane.

!971 C10 long bed w/ 350 trans. shift kit, 3:07 rear (I think)
Block: '74 350 4 bolt rebuilt by prev. owner. cylinders/compression great
Deck ht. .0235
bore: 4.01
Pistons: flat top w/ 4 valve relief 5cc
Cam: Engine pro MC1988
214/224 @.50
443/465 lift
107 lobe intake, 117 lobe exh.
882 stock heads
HEI 50K Volt dist.
Torker 2 single plain intake w/ 600cfm edelbrock carb
Hooker header 13/4 ?, 3 inch exhaust

Was thinking of changing to:
Dart iron Eagle heads:
72cc
165cc intake runner
65 exh.
1.95 valve intake w/ 4 angle
1.5 exhaust w/ 3 angle
Weiand 8120 dual plane intake
Fitech GoStreet 400HP EFI
4.1 bore .026 thick head gasket

I figure compression will be about 9.235:1
Quench about .049

Is the compression too high for 89 octane? Will I have detonation problems with this setup?
I'm a newbie at this so any feedback/advice would be greatly appreciated, thanks in advance.

[66Submarine]

I have that cam with Vortec heads in my truck right now. .038" quench with flat top pistons for 10.3:1. IIRC the timing is 12º initial and all-in at 32º or so. On 93 octane I could never make it knock. On 89 if I pull it down hard at very low engine speeds it does (only seems to do it below 1,200RPM), but I'm driving it on 89 now.

[rrl692000]

I was originally going to use vortex's, (thinking it had dished pistons) but now was thinking it might have to high compression without using a thicker gasket and increasing my quench. Would like to keep it in the low 9's just to be on the safe side. Looking at yours then it looks like I should be good. Thanks for the Info.

[66Submarine]

Yeah, you should be good (IMO/IME). FWIW, I've also been happy with that cam so far (actually built the engine for a car). Just how low are you talking about when you say "lower RPM range", though? If you are never going to wind it up you might benefit from a slightly smaller cam.

You Tube

You Tube

[rrl692000]

I'd say most of the time just regular driving, probably between idol and 4200rpm, and every once and awhile get on it some. That's the cam the previous owner put in it and I like the way it sounds, but it just had no power/pickup when you gave it a little rump, probably do to carb problems and mis-matched parts. Just hoping what I've come up with to go with what I've got is a good match.

[rrl692000]

c10

[geezer#99]

, but it just had no power/pickup when you gave it a little rump, probably do to carb problems and mis-matched parts. Just hoping what I've come up with to go with what I've got is a good match.[/QUOTE]

Likely all you need for more power is more initial timing. Especially at your elevation.

What's your initial timing?

[rrl692000]

initial time was 10 and 34@ 2000 RPM. I never could get the Edelbrock (1405) adjusted right, way too rich even with smaller jets/rods. That's when I decided to just try the FiTech EFI, then bought a new distributor, then just kept going till I had the heads off since they are the low compression 882's. Also thought about going aluminum. Edelbrock has some 70cc 185 runner heads for $889, but they have the bigger 2.02 valves, which I thought would be too much for the lower Rpm numbers I'm after. Any other options around the $1200.00 mark?

[geezer#99]

10 initial isn't much.
Should be able to crank it up to 16 or 18.
At higher elevation you need to start the fire earlier.

[rrl692000]

Ok, I'll try that when it's all back together. As far detonaton which would be better?
9.23 :1 compression with .049 quench (.026 gasket) or
9.4:1 compression with .043 quench (.020 gasket)
Or am I safe either way?

[geezer#99]

I don't know!!
Simple as that!! LOL!!

But how do you arrive at 9.4 compression by changing only the head from 76 cc to 72 cc.

[rrl692000]

That is with using the 72cc head. Using the online calculator if use the .020, 4.14 bore gasket I get 9.379. Using the .026, 4.1 bore I get 9.26: 1. Am I doing it right? I usually just work on my engines, not build them, so I'm hoping I'm doing all right.

[Marshy]

Originally Posted by rrl692000

Ok, I'll try that when it's all back together. As far detonaton which would be better?
9.23 :1 compression with .049 quench (.026 gasket) or
9.4:1 compression with .043 quench (.020 gasket)
Or am I safe either way?

If your numbers are true I'd use the thinner gasket every time.

Sounded like you were on the right track. Ditch that Torquer 2 single plane intake, you want a duel plane. Your 1-3/4" headers and 3" exhaust are on the large side given your engine build. A set of 1-5/8" headers would be better suited as well as 2-1/2" exhaust pipe. Using the smaller exhaust pipe would save you money too without hurting performance.

I figure my engine is at 9.6:1 with .035" quench, stock Vortec pistons and Vortec heads. I run regular pump gas with initial timing at 10* and all in at 2500rpm for a total of 32*. If I'm pulling a loaded car trailer then I will get a little spark knock but it goes away if I run mid grade fuel.

[geezer#99]

Originally Posted by rrl692000

That is with using the 72cc head. Using the online calculator if use the .020, 4.14 bore gasket I get 9.379. Using the .026, 4.1 bore I get 9.26: 1. Am I doing it right? I usually just work on my engines, not build them, so I'm hoping I'm doing all right.

What online calculator are you using?

Here's a link for more info.
http://www.crankshaftcoalition.com/w...pression_ratio

[rrl692000]

Not sure of the header size, but i do know that it's 3" pipes. I'll have to check the receipts on the headers when I get home tomorrow. Also plan on checking all my numbers again, especially the piston to deck height. if my headers happen to be the 1-5/8" will the 3" pipes effect it that much?

I've been using multiple calculators, but mostly the one at uempistons.com

Thanks for the help guys, I really do appreciate it.

[Marshy]

Originally Posted by rrl692000

Not sure of the header size, but i do know that it's 3" pipes. I'll have to check the receipts on the headers when I get home tomorrow. Also plan on checking all my numbers again, especially the piston to deck height. if my headers happen to be the 1-5/8" will the 3" pipes effect it that much?

I've been using multiple calculators, but mostly the one at uempistons.com

Thanks for the help guys, I really do appreciate it.

It's not uncommon to have 1-5/8 headers with 3" collectors. I would suggest using a reducer to go from 3" to 2.5" and make the rest of the exhaust 2.5". Your wallet will thank you and so will the exhaust builder. It's just a little simpler to work with and your engine won't be able to take advantage of the extra exhaust size anyways.

[rrl692000]

Ok, so as of now it looks like I'm going with this setup using the .020 head gasket putting me at 9.35:1 with .043 Quench. Plus reducing my exhaust down to 2.5".
With this setup should make pretty good low end torque and 300+ HP? My goal was to get around 330Hp.

[geezer#99]

Did you figure out how far down in the hole your pistons are?

[rrl692000]

Do you mean have I re-measured to see if .0235 is accurate? Not yet, won't be back home till tomorrow?

[geezer#99]

YUp!!
That's what I was wondering!
Couldn't understand how you arrived at a quench without an actual measurement.
You might be in for a shock when you measure it.

[rrl692000]

I did measure, I know it's somewhere between .020 and .025. Just wanted to double and triple my measurements. You know, measure twice, cut once, lol.

[Marshy]

Originally Posted by rrl692000

I did measure, I know it's somewhere between .020 and .025. Just wanted to double and triple my measurements. You know, measure twice, cut once, lol.

If it is 0.025 deck clearance I'd suggest you consider using a FelPro 1094 steel shim head gasket. They are 4.100" diameter and .015 compressed thickness. They are coated with a sealant also.

[rrl692000]

Thanks Marshy, I'm going to recheck my piston to deck and use some clay and syringe to measure the 4 valve reliefs on the pistons. I'll post my findings tomorrow.

[rrl692000]

Sorry, it was my wife's birthday yesterday. So after remeasuring I get 4.3 cc's on my piston heads and .035 on my piston to deck height. So I'm going to have to use the Felpro .015 head gasket, that should put my compression ratio at 9.3. Unfortunately it raises my quench to .050. I have read the newer 1094 has a clear silicon covering it instead of the black rubber it used to have and Felpro says to install dry, but a lot of people say use the cooper spray on them. Any advice as to whats better?

[Marshy]

Originally Posted by rrl692000

Sorry, it was my wife's birthday yesterday. So after remeasuring I get 4.3 cc's on my piston heads and .035 on my piston to deck height. So I'm going to have to use the Felpro .015 head gasket, that should put my compression ratio at 9.3. Unfortunately it raises my quench to .050. I have read the newer 1094 has a clear silicon covering it instead of the black rubber it used to have and Felpro says to install dry, but a lot of people say use the cooper spray on them. Any advice as to whats better?

I talked directly with FelPro about those comments left on summits feedback. FelPro said they changed the coating compound to it was clear, no sealant is necessary. I used a very light coating of the Permatex coper spray on mine just to make sure because I didn't know the surface finish on my block and heads. I think you could go either way. If you want a warm fuzzy feeling give them a call and ask about using a coper spray coating and confirm what they say.

Regarding your quench, .050 isn't optimal but it would work. I haven't looked at gaskets thinner than 0.015 so I don't have any recommendations. I think with the cam you have, if you could find a good 0.010 head gasket the little extra compressionn it would add wouldn't be an issue.