[AlabamaThunder]

Alright I have a 72 Chevelle that im building a .60 over 350 for..361 now right?

Anyways, this is how my build up is looking.

Sealed power hyper flat-tops
GM X rods
GM cast crank
Summit 3,000-6200, 234/234 Duration, .488/.488 Lift Cam
GM 305HO 416's ported mildly with stock size valves
Z28 valve springs, Summit roller tip rockers

So 10.5-1 is likely on comp. ratio, with the 60 over flat tops and 305 heads? Is this thing going to hate the taste of regular?

Now heres where I need help.

I have three intakes and i don't know which would be best.

Edelbrock performer, or a performer RPM, or a perfomer EPS?

I'm going to be running a Carter AFB 600 for right now.

Also, this chevelle had a 305 late 70's truck motor in it when i bought it...wore out bad...spun a bearing a few weeks ago.. And the rear end is a 10 bolt peg leg, and I have no idea what kind of gear it has, so I don't know what kind of stall to use.

I have a 3000-3500 stall, would I mess it up if i ran it with say the worst gear it could have...a 3.08?

I'm really excited this is the first motor I've ever built. And I'd hate to ruin a good stall

I have another converter but i have no idea on what the stall might be it's a 12" how can i find out what stall speed it is? The guy i got it from said he had it behind a built 327 and thats about all i know.

Also, is this cam I going to be about right, or is it to much?

Also what kind of power do you think I'll be making? Anyone like to make a guess?

Thanks for the help, Jensen

 

[smitty454]

doesnt 305 heads on a 350 shoot the compression through the roof?

 

[AlabamaThunder]

doesnt 305 heads on a 350 shoot the compression through the roof?

Shouldnt with flat tops, 305 heads are 58cc...should be around 10.5:1...if I put say a 350/400 76cc head on it...it would probably be around 8.5:1

 

[77 cruiser]

Or bout a 1/2 point higher zero decked. The ports @ valves are also too small on the 305 heads don't think you'd be real happy with the combo.

 

[Schurkey]

Cast crank is good for about 6K RPM.

305 ports 'n' valves probably sign off earlier than that.

Too much cam, too much compression--or, put another way, NOT ENOUGH CYLINDER HEAD provided you're confident the bottom end can handle it.

 

[jpete]

I had the same motor several years back. I used the 305 heads from my '78 Camaro on a 350 "010" block that was .060" over. It even had sleeves in 2 cylinders from a previous explosion. Cast crank and the Edelbrock "Performer" package. M-20 with a 3.08 peg leg.
It ran really strong with no problems at all. Minor oil leaks through the intake bolt holes but that was it. I never could get them to seal......
I don't recall having to use any special gas.
It was a nice street motor that just ran and ran. I drove it to Florida from Rhode Island in August and it never ran hot. I flat footed it to New Hampshire for the first Super Chevy in Epping. 2 hours door to door on a normally 2.5+ ride. I buried the needle on a 125MPH speedo I was young and foolish then.
In that Camaro, I'd say it was a 15 second car or so.Maybe high 14's. I was always afraid to run it thinking I'd blow the rearend or something and be 2 hours from home.
I say build it and enjoy what should be a solid reliable engine.

 

[caribbean]

As your home built project - build it and enjoy it

UPSIDE
Some friends of mine put 305 heads on a 60 over in a pickup - and that swap alone turned the engine into a monster - it would light up the tires at will

anything dual plane should work on the street

DOWNSIDE
detonation was never too far away with the combo if you use a small street cam - and it showed on the plugs - your cam is bigger and should prove better to handle higher static compression

go with colder plugs - readily available AC R43ts type plug
and conservative on the timing advance -

It will work - just plan around it- & light her up

 

[AlabamaThunder]

What do yall think on the 3500 stall? think it will be fine to use untill i get some better gears out back?

Also, how hot do you think this motor is going to run with a 2-row radiator, being .60 over and all?

With running the stall should i go ahead and invest in a tranny cooler?

 

[AlabamaThunder]

Thought i would give you guys an update. I got the engine built and in the car, got it running and broke in the cam, then went and broke in the rings...after I just parked it until the night after ..

I got in it and took it down the road and it pulled through first really good shifted into second it just shut down at about 3400rpm,coasted into a old friends driveway and we tried to start it. it crank and ran but with the wildest knock ive ever heard.Took it back to the shop...pulled it and tore the heads off of it and started turning the crank.

I seen exactly what it was then, the 7th piston wasn't moving,stuck at the top. i took a small screwdriver and pried it out. all i have left is the piston from the roof of the wrist pin housing...the pin was still in the rod and had been drug through the cylinder wall. you can fit you're fist in the hole. The skirt was busted into peices which i found the deaper i went.

Also ruined a freshly turned crank and X rod.

Was the a piston failure? Brand new hyper fed. mogul piston.

Anyone ever dealt with contacting and company of dealer about something like this? I mean it destroyed everything.

Any ideas as to what could have caused this guys?

 

[Guest]

It's your's so build it but watch for detonation.

pdq67

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[MidWestOutlaws]

Cast (hyper) pistons will crack if detonated.

 

[Motorhead62]

I would try your engine combo as is. Others have stated it will work.

I think 3500 RPM will be too high for the stall speed. I would prefer 2500 RPM.

Good luck.

 

[mgt999]

I would try your engine combo as is. Others have stated it will work.

I think 3500 RPM will be too high for the stall speed. I would prefer 2500 RPM.

Good luck.

I think if you read his last post, he did try and it blew chunks.....

 

[jpete]

Sound terrible. Sorry for your loss. I think that the pistons are quality but anything can fail. I wonder if it was damaged when it was installed? I nad cheap Badger cast pistons in mine and beat the snot out of it regularly so I don't necessarily think it's the pistons "fault".

 

[AlabamaThunder]

I dont think yall understand what im saying. The top half of the piston is perfect all the way down to the wrist pin. If it was caused by detonation, then why is the top perfect?

Also to prove how weak these pistons are. A buddy of mine ordered the same kit i did, and was putting the rods and pistons together and laid one on the trunk lid of his chevy 2 and it fell off and busted in to peices...like literally busted into pieces..leaving the wrist pin in the rod. He ordered another piston and sent the kit back after thathappend to him and what happened to me.

 

[diesel158]

You just answered your own question,[email protected] pistons.