My 79 L-82 bored .060 over has an ES888r cam ,flattop 4 relief pistons, and true 2 1/4” duals. I would like to keep the original aluminum intake and qjet as I move forward. I contacted Summit yesterday and they recommend e-street 5089 heads with a set of flotech long tube headers. I was hoping for some input from knowledgeable enthusiasts. I am trying to get around 300-350 hp if possible for my $2K investment.

 

The L-82 engine was basically the same as the older L46 engine, which was factory rated at 350 gross horsepower. The only real difference was the L-82 had a lower static compression ratio, and was rated using the net horsepower method. Anyway, you have a significantly larger camshaft, the new heads will increase static compression ratio and flow significantly better than the stock heads, combined with headers and dual exhaust I don't see why you shouldn't be able to see AT LEAST 350 horsepower at the crankshaft, probably even more than that. At the wheels on a chassis dyno? Who knows, you'll have to run it and see.

Scotty

 

These are the specs on that cam

• duration @ .050: 234/244
• lift: .488/.509
• lobe separation: 107

No way I would ever recommend that cam for the street in a low CR (relatively) 350 CI motor. It's more of a circle track cam meant to make HP at high RPM and stay there.

Are you looking to replace the cam as well?

 

Funny that you say that,as the machinist that I bought the parts from after he did the machine work on it races circle track. Truth is I have been driving the car for about a year now and it is running pretty good but I want more. I was hoping to just add heads and headers and have a fun ride. I figured if I was only going to get 7 mpg (which is what I get now)then I want some zip.

 

I think that LSA is a typo or something, the intake and exhaust center lines are listed as 107/117, which tells me the LSA is actually 112. It sounds almost identical to Summit Racing's house brand 1107 camshaft, except their cam is on a 114 LSA. Summit's cam has a basic operating range of 3,000-6,500 RPM. I suspect that there is some kind of misunderstanding here, because I can't help but think that a cam that big in an otherwise stock engine would really run like crap. Better heads with smaller combustion chambers, better flowing ports, and long tube headers would probably make a drastic improvement. I bet that thing would barely be able to get out of its own way just putting around, but once you hit about 3000 RPM, it would start to pull hard! If you have a manual transmission and a steep gear out back, it could be fun to drive, if you're into that sort of thing.

Scotty.

 

ES 186R is the cam he sold me. Sorry for the confusion so I just spoke to him and thought I should do more checking on compatibility of parts before moving forward

 

Better specs, still very aggressive for a 350 on the street at lowish CR.
Note the RPM operating range.
LSA now 109 which is a lot better than 107.
For that cam I would want more like 112.

Given that advertised duration the overlap computes @ 73*. A good street motor has 35* to 55* of overlap. It will run and make power, but with low idle vacuum and the power will be much later in the RPM range. Peak torque may not occur before 4800-5000 RPM.

Cam Style:
Hydraulic flat tappet
Camshaft Manufacturers Description:
Rough idle.
Basic Operating RPM Range:
3,000-6,000
Intake Duration at 050 inch Lift:
230
Exhaust Duration at 050 inch Lift:
230
Duration at 050 inch Lift:
230 int./230 exh.
Advertised Intake Duration:
287
Advertised Exhaust Duration:
287
Advertised Duration:
287 int./287 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.480 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.480 in.
Valve Lift with Factory Rocker Arm Ratio:
0.480 int./0.480 exh.
LSA 109

I found this regarding the flow numbers on the recommended head.

The intake to exhaust ratio is 65% looking at the .500" stock flow numbers. About what you would expect for an entry level as cast aluminum head. Typically that would dictate an intake to exhaust duration split on the cam. However to split that duration on that cam would mean even more overlap = not good for street.
With 64cc heads you'll be around 10.0:1 CR a decent place to be for a street car. With that cam more CR is going to be better and you may want to shave the chamber down or look at a different cam. I would want 10.5 :1 or thereabouts for that cam. Just depends on what you want out of the car performance wise and what seems affordable.
It will be a bit lazy down low. If it's an automatic a higher stall (3000rpm) converter would be a good idea.

Being it's an L-82 you should have at least a 3.55 rear ratio maybe a 3.73?

Good idea on the exhaust by having long tube headers. Exhaust pipe diameter seems small to me for an engine that likes high RPM and a cam that will not like back pressure. 2 1/2 would be a min for me.

 

Right now I have a block with the aforementioned cam and pistons sitting on my engine stand. I have an nos intake with a 750 qjet attached. Is there a way to get a respectable bump in power by adding heads and headers and possibly changing the cam for under $2k? If so some specific info would be great. After speaking to Jegs the rep wasn’t sure 350 hp was probable with the parts combination suggested by Summit. I would really only make the investment if it is “streetable ” Thanks

 

I can tell you that I paid $300 for the used dart heads on my car now that im about to replace. I also have about $650 total into building a set of aluminum 64cc/ 195 heads with the machine work and hardware I needed minus the springsand roller rockers I already had (from current $300 heads). I bought the newer chinese heads being machined and sold by many like AFR as their enforcer heads or skip whites NKB heads so if your looking for more of an assembled head but with similar but slightly better flow numbers than those elelbrock heads on a budget I would suggest the AFR or NKB assembled heads.
Flat tappet Cam/ lifter combos are cheap. like $300 ballpark for the combo.
I have stainless sidepipes which have skyrocketed from the $650 I paid new so cant comment on the cost of the headers but I would still confidently say you should be able to accomplish your goals for 2 grand... thats about what I paid for my whole rebuilt flat top 355 engine build including retro roller cam setup but I'm frugal and shopped around.

 

The xe268 or 274 would be good for a 10:1 CR An xe262 if it's closer to 9.5:1
https://www.compcams.com/xe268h?gcli...xoCs7UQAvD_BwE

https://www.compcams.com/xe262h?gcli...RoCTqgQAvD_BwE

Then there is the xe274 if you want higher Hp at a higher RPM, or have more CR to work with.

https://www.compcams.com/xe274h?gcli...RoCeJIQAvD_BwE

You can compare the HP's on these dyno's note that they are all at 9.25CR and 1 5/8" primary headers. With more CR and larger primaries you could expect a little more on the 268 or 274 I suspect. Note the differences in vacuum levels at idle as well.

The heads you've looked at could develop 400 ish HP given a good combo. You can take the intake flow rate double it and multiply that by .8 to get a good guess at your achievable HP for an average effort build.

Do some research on flat tappet lifters. There has been a pretty prevalent problem with lifters and failing during break-in. I'm not a big fan of flat tappet but if 2k is the budget then that's where you're at.

 

Since time is a luxury I have for the time being, I will do my due diligence and start researching. Thanks

 

I replaced my my flat tappet voodoo 262/268 cam which is one step smaller than the xe268 with a comp xe270hr retro roller cam and it was a noticeably positive step for me. I paid about $285 for the new camshaft and about $130 for these lifters to go with it which made the upgrade a lot more economical than identical comp branded $600+ retro roller lifters. https://www.rockauto.com/en/parts/en...ve+lifter,5548 They are once again out of stock at the moment unfortunately but I researched them before purchasing and found only good feedback. My 355 engine is at 10.16:1 compression with the 64cc chamber 180cc runner current heads, 4 relief -6cc speedpro flat top pistons and the felpro 1094 .015 shim gaskets and .6RRs. desktop dyno gave me these numbers,

With the flow numbers on my new head the power has increased a bit from here.

 

One of the most intriguing things I’ve read is to try porting and polishing my factory heads and throw on a set of headers. If I don’t botch the job it should be interesting to see the results.

 

So I bought the $300 aluminum castings from AT racing on ebay and ported them myself. The flow numbers measured by others who had done this on youtube were impressive as these heads are more or less clones of the Dart pro 1 heads. They are decent quality heads and used as the economy version sold by blueprint on their crate engines as well as the enforcer series heads from AFR, Theres another american head company selling them but I cant think of the name off hand.
Everything ive read so far including David Vizards book on porting states polishing the ports has no real benefit on a street engine.

 

I’ll be darned. Thanks for information

 

No benefit to polishing the intake side as the rough surface helps with keeping fuel in the stream or at least fuel that drops out to be re-atomized. Polishing the exhaust side and combustion chamber may have benefits from preventing a rough surface for exhaust particles to stick to and carbon up the port/chamber.

Doing either to a stock head is a waste of effort as is porting the stock heads. It would take so much time and effort for very little benefit and ANY aftermarket head is going to flow better.

Op, if anyone knows how to get a job done on the cheap and still get reasonable stuff it's augiedoggy.

 

All things being equal last question on upgrade. Cam is a stage 3 so I think I need a stall converter around 25 to 28 hundred. I measured the stock flex plate at 11.5” and want to know if this sounds correct for a stock th350 moving forward. Thanks

 

168 tooth. NOT 153...

 

168 teeth and measures 5.75” from center of flex plate to center of tc bolt hole. Want to make sure dimensions sound correct so I can match up a usable stall

 

Absolutely ditch that 2 1/4" exhaust when you get headers. 2.5" mandrel-bent minimum. Get GOOD mufflers (not just popular ones), and a properly designed/made/located X-pipe to top it off.