Well I figured I wanted piston to head clearance as close to .050'' as possible. It turned out after squaring the block, each piston was .012'' below the deck, with the common .039'' thick felpro gaskets, it would give me .051'' of piston to head clearance. It was close enough and even on all cylinders, that I figured I did not need to shoot for that extra .001''.

I figured with these numbers, the 3cc valve relief on the pistons and and the 58cc combustion chambers on the stock heads, I would be at 12.24:1 compression. I figured this would be pushing it to run on pump gas, as we mainly have 91 octane around here, but it should be ok since we are also about 4000ft above sea level.

Granted I didn't plan this build before starting it, I also only have about $1250 into the short block with machine work, balancing and an all new forged rotating assembly. The only part I did not do myself was the balancing and installing the splayed main caps.

This car is basically going to be a weekend warrior, I plan on being able to drive to the drag strip which is about 60 miles away and also drive it to the occasional show or cruise night, but I am also setting up the suspension for the occasional track day and auto-x.

I plan on porting my edelbrock intake to match the cylinder head flow. I have not yet figured out what size injectors I need to run on this motor.

I would have to check to make sure, but I believe it is a hughes torque converter. I don't have any emissions requirements where I am from and I don't mind a somewhat lopey idle.

 

The Edelbrock LT1 intake is JUNK.

Who told you to look for .05 quench? Most builds aim for .035 or a little less.

How did you come out so cheap? Once getting line bored for new caps and with balancing and everything I would expect the machining bill to be that and the parts bill to be several times that with caps and such.

 

And $1,250 includes "all new forged rotating assembly"? What are the specific parts included in an apparently low $$$ "forged rotating assembly"?

 

First off I chose to go with .05 quench due to piston to valve clearance issues I had on the last stroker motor I built. I typically try to go with .04 quench on all of the circle track motors I build, but this is only the second stroker motor I have built and due to the problems I had with the 383 I built I was trying to have a little more clearance on this motor to account for every thing. I also figured if I shot for the .05 quench that it should allow for me to go down a little on head gasket thickness if possible. But after figuring my compression ratio, I doubt I will come down any on the quench unless I use different heads with a bigger combustion chamber.

Second, the primary reason I did not plan this build before buying parts, was the great deal I got on the rotating assembly minus the pistons and rings. I was also able to do all of the machine work myself, except for installing the main caps, line boring and balancing. The machine work I did have to have done was also done at a less expensive rate due to all the work I send to the macine shop when I am building circle track motors.

BTW it was supposed to say $1750 for the short block build, but any way here is the breakdown of my costs.

Main Caps $200
Pistons $500
Cap install and line bore $200
Balance Rotating Assembly $200
Piston Rings $100
New Crankshaft, Rods, Bearings, Harmonic Balancer and Flex plate $550 from a local guy that gave up on his project.

Just curious, why is the edelbrock intake junk, I still have the stock intake and I am not opposed to porting and running the stock intake.

I think I am going to change the title of the thread to get more help on choosing top end parts for this build. I appreciate the help from you guys. I know how to put together a motor and do most of the machine work, but with most of the motors I have built, I have had it pretty easy since our circle track classes all have specific rules regarding what parts you can run, and all of the head work and port matching is done by the local machine shop. Most of the guys I build motors for have the combination they like to run and just count on me to assemble and meticulously check all of the clearances and specs during the build. Guess you would consider myself more of a motor assembler than a motor builder. But anyway thanks for the help.

 

Correct me if I'm wrong but what does the quench distance on your last build have to do with the quench distance on your current build? I run .032" of quench in my 383 and still have tons of clearance. LT1s love a tighter quench so I'd concentrate on bringing that down.

It's hard to improve on a good thing. The Edelbrock intake is just a gimmick. It's actually been shown to COST HP rather than help it. Stick with the stock one. I'm putting down the numbers in my sig through a mildly ported stock manifold.

Since it seems you're new to building LT1s why not find a (successful) combo from someone else on here and try and emulate it. Eliminates guesswork and gives you an idea of what to expect in terms of HP/ET.

 

11.5 to 1 compression is still a good bit of compression and will make great power if the cam and heads are there to support it. Granted the LT1 can handle more and being at high altitude also will tolerate/require more comp, but dont think that it wont make power at 11.5 With the big stroke, the heads will need to flow. Need a larger port. Pretty correct on the 280xfi cam. Great cam for what it is, but its usually done at 400whp +- 15 hp depending on the build on the current 113 lsa. Great 355 cam, and pretty good on a 383 as well. I dont think its enough for the 396. The 292xfi would be better out of the xfi series but it will depend on the heads.

Piston to valve clearance is more cam related than "quench" height. Shouldnt have a problem with strokers if the cam is selected and installed right at .03x to .045" clearance

Your build has potential tho. With the good deals you had on parts, you are ahead of the game. More cubes on the street is almost always a good thing. The torque will be nice. Huge torque curve. Just need to save up for proper heads to take advantage of the bottom end. Else just enjoy what it is. No problem making "only" 500 hp at the motor with 396 cubes. IT will have more torque than a comparable 355 and be alot more street friendly. Still should be capable of 11's if the car is lighter than 3600 lbs. Heck I've been 12.15's with 308 whp at 3560 lbs in my 4th gen. All about track conditions and setup. At your 4000 ft however dont expect to compare to other cars on this board running in mine shaft air....

 

Ok so heres the plan, ditch the edlebrock intake, go with .029'' thick head gaskets to get my quench down to .041''.

So, with this quench, I can get the compression in any where from 11.97:1 to 13.3:1 depending on the size of combustion chambers I run. With these LT1 motors, what would the ideal compression ration to run on pump gas for both the street and racing, there is race fuel available at certain times of the year, but I definately do not want to be dependant on it. I know it depends on the cam, but I have pretty much decided to just go with a complete top end from AI, cam, heads, and intake porting.

So that narrows it down to either the Ai 238 / 244 - .599" / .599" - 108 LSA or the Ai 244 / 250 - .599" / .599" - 110 LSA. I like the first one bacause of the lower RPM peak power, but it is also recommended for a 383 while the second is recommended for a 383 or 396.

Next, since I have decided to definately go with AI, I seem to have run into 3 head options, for the price vs. performance which would you recommend, The LT1 200cc head work, the TFS 212cc heads or the 215cc LT4 head package. I don't currently have a set of LT4 heads, but I know of an untouched pair I could probably get for around $500, but I would also have to find a LT4 intake correct?

 

Forget LT4 heads even exist they work far better in benchracing than they do in the real world. I know all the popular porters offer options for them but the common story I hear is when folks call asking about it they try and sway people away from the LT4s.

Chamber volume wise with a flat top 396 I think you are best looking at the AI Trickflows.
If you had gone with some minor dish or something it would be easier to get the 200cc heads to work but with the mediocre quench you will have I think you should keep a big chamber and not try and run the compression too terribly high.

 

Trying to open up piston to valve clearance by running a thicker head gasket is the wrong way to do it. Notch the pistons or advance the camshaft. 1 degree on the cam can do wonders.

You got a good deal on that stuff, assuming it's quality hardware.

The Edelbrock intake is not junk like he wants everyone to believe. It's simply not worth spending money on since it offers virtually the same performance. I've seen dyno results where it lost 1-2hp and others where it picked up 2-3hp. That could very well be dyno variance from run to run. To me it's more of a "bling" piece then a performance piece. It does look very nice. I'd be curious to see someone do a test of a heat soaked engine with an LT1 manifold versus the air gap Edelbrock manifold. I'd bet money that it cools down faster than the stock piece which could result in better ET's from guys at the track hot lapping. It might weigh less too. I've never seen anyone report on the weight though.

Just a side note- how much p-to-v clearance are you shooting for?

 

Maybe "junk" is the wrong term. I have seen no build quality issues. It is a $465(summit and the like) performance piece that fails to deliver performance gains and one of the "shortcomings" of the stock LT1 intake has always been considered the small plenum volume which the Edelbrock DRASTICALLY reduces something like 28% from memory. In the case of a larger displacement engine and turning more rpm more plenum volume is generally considered to be the right way to go. It is one of the arguments many use for converting gen 1 single plane intakes.

I haven't seen it tested but if we are going to benchrace the plenum volume issue would probably be an even bigger issue on a stroker turning more rpm.

Fact of the matter is that in the late 90s Edelbrock and Lingenfelter admitted defeat on a simple bolton improved LT1 intake that would fit the low hoods of the cars it was used in. A decade later when GM stopped having the LT4 intake made(which was never a flow upgrade either) it created a false sense of a "need" for an aftermarket option and Edelbrock went ahead and released a product that does not offer a power gain. Hell their entire LT4 package heads/cam/intake makes less flywheel power than what people expect at the tires from ported GM LT1 heads and cam with untouched intake.

I truly wish Edelbrock being a somewhat American manufacturer would make good products for us but they choose to release pieces for sale that aren't really worthwhile improvements and the only way to force them to resolve that is going to be to call them out on it. If we keep letting folks blindly believe based on nothing but the name that things are good then they will keep selling more of the same.

 

Out the box it may not offer gains, but what about its porting potential? Does it have enough meat to be opened up to 1206 gasket+ ? Whats the most the stock LT1 intake can be ported?

Thats what I'd like to know before passing judgement on the intake. TPIS Miniram is sorta an LT1 intake and on sbc's its been used to make BIG power. I have seen however single plane EFI's beat that intake on big inch motors, but to its credit, the miniram wasnt ported. Tony at AFR has done a miniram for a 450" sbc using AFR 235 heads and that intake was cut/epoxied up to flow 400cfm on the bench. HUGE port increase to fit the large heads.

Not that most guys need that capability but it be nice to know it was there. For most builds it seems a stock to mild ported LT1 intake will feed it.