I am taking my engine out tomorrow because it needs a rebuild and would like to ask few questions.

The plan is to bore the block out by 0.10 to clean the bores and keep my standard iron crank. I will replace the con. rods with GM LT1’s and go with Hypereutectic aluminium pistons.
I am thinking of +/- 10:1 compression ratio with alloy heads and my ideal operating range would be 1800-5500RPM and running on premium fuel.
I like the AFR Eliminator Street aluminium heads with 65 cc Chamber and can not make my mind up weather to go with 180 or 195 cc intake.

Which head should I go with 180 or 195 cc and why?
What is the difference between straight and angle spark plugs [besides of the obvious]

Thank you
Paul

 

Paul, the AFR's are an excllent choice and flow great.
I'm assuming you have a 350, not a 383. The 180 heads are the way to go if you have a 350, the 195's if you have a 383 or 400.
The angle plug heads have clearance problems with plug wires and headers, several posts on this one.
Yse the straight plug heads, I know you will be using headers with the ARF"s.

 

Yes it is 350 CI

AFR website says 180cc for 350ci and 195cc for 350-400ci.
What would happen if I was going to go with 195cc for my 350 + 0.10ci engine?

 

You would have to get into a radical 350 and rpm range to take advantage of the 195's.
For the rpm range you listed and excellent low and mid range torque the 180's are the match for your engine

 

Another note, the 180's will give more fuel/air velocity and fuel atomization in the 350.
The better the fuel and air mixes the better the combustion.

 

The 180's are fine and preferred for what you are now aiming for. The only reason to buy 195"s might be if you ever decide in the future to go up to a 383 or a hotter 350 they may be worth considering. The debate between them is pretty much a bench racing hair split IMHO.

-Mark.

 

 

All I want for now is to have my 80 back on the road.

The head purchase is going to be the most expensive part of the build and the way I look at it is this:
180cc are OK for now, however what if two years from now I will want more power.

Will the 180cc heads be good enough for 383cid engine or will I have to go and buy another set?

How will I notice the difference between 180cc and 195cc heads in real world in 350 and 383 cid engines?

P.S. I do value your opinion as all of You have lot more experience with engine building than me.

All I am trying to do for now is to understand engine components and how they all work together to achieve the best possible combination.

One more thing
My car has Manual gearbox. Am I unnecessarily limiting myself with 5500RPM?


Thank You
Paul

 

You didn't say anything about future plans. If you are considering a 383 in the future, why not do it now. A clean up bore will require new pistons anyway. You can get a cast stroker crank for a couple hundred or a complete kit with crank rods pistons etc., which is the best deal. It will live a long life below 6000 rpm and you'll have gobs of torque.
You can use your stock rods with the right piston too. It's up to you!

 

You have to go eazy on me one step at at a time please.
It took me a year to decide to rebuild my engine!!

 

I didn't mean to be harsh, just giving ya some good advise in my humble opinion.
One thing you need to know about a 383. If you don't use an internally balanced crank, you'll have to replace the flywheel with one that is counter-balanced and the harmonic balancer. Eagle makes a internally balanced forged unit for around 500.00.
Talk with your builder and get their feedback on doin a 383 now as opposed to doing it all again in a couple years. You'll save a ton of money if you do it now.
You'll have gobs of fun with the torque of the 383.

 

Paul you're not allowed to have an engine with more power than mine.

 

On reflection 383ci is a bit radical for me!
Let’s stick with 350ci and use the 180cc heads.
So that I understand this, at what point if any should I consider 195cc heads with 350ci?
Thank you
Paul

 

Ben, Go to bed!!!
I need you fresh for tomorrow!!!
The engine is waiting for you!!!

 

I'm going to drop your block in the middle of the road tomorrow.

 

Paul:

My initial 350 build used L-48 dish pistons, a CC 268H (not XE) cam, TF 23* 64cc heads with 195cc runners, true duals, Edelbrock Performer intake and modified Q-Jet. I ran this without problems, on a 4-speed, for over 2 years.

Reused the heads and Q-Jet only, when I built my 383 last year. Heads worked fine with both set ups.

BTW, the 350 did 217 RWHP on a Mustang dyno.

 

This is probably a silly question, but if I do not ask I will never know!

After long time researching the 180cc v 195cc heads {so many different opinions} I still can not decide weather to buy 180 or 195. :o

If 180cc is too small and 195cc too big why nobody makes 187cc
heads?
This would be right in the middle of these two and would be ideal for 350cid as well as 383cid engines???.

What do you think?

 

why are you thinking about replacing the rods? for the RPM usage you are describing your factory rods are more than adequate (vastly) and you certainly dont need to upgrade to the high end small block rods for that.

If you are just hell bent to have new rods a set of SCAT rods would be cheaper and just as reliable.

No need to spend money where it doesnt need to be spent. Excellent choice of heads though (180)

 

Paul, as suggested, go with the AFR 180cc heads if you have no plans in the future to stroke it. This past spring I finished a complete top-end rebuild of my 79 L-48. I used the 180cc heads and had them milled to 60cc for best compression with the rest of the parts I installed. I upgraded my cam, rockers and intake manifold. Headers and dual exhaust are a must. The heads are were the power is at. Figure out now what your goals are and what type of budget you have. In some cases it might be best to just go with a crate motor instead of wasting time and money on your original.

 

C3Paul, ever get the feeling folks are dancing around your real questions? Here are my thoughts on this.

No need in buying angle plug heads. From what I have read it is more of a personal thing than a performance thing. I happen to run the L98 heads with angle plugs only because they are light and cheap. I also have the proper headers for them and don't have any problems with wires or plug clearances.

If you have the money for the 383 it would be best to do it now rather than "wait a couple of years". Since you are familiar with how the stock engine performed, I am betting that you will be thrilled with how your rebuilt engine performs and will forget the 383 itch. I wanted a 383 too, but didn't want to spend the bucks and now I am glad I didn't. My little ole 355 will light em up until you are forced to let off or lose control.

As for the 180 or 195, easy rule of thumb, smaller runner = more torque at lower rpm. Bigger runners slow the fuel/air mixture at low rpm and don't offer any advantage to a street driven car until you spin it up in the rpm range, which doesn't happen often. For your given rpm range the 180's are [B]plenty big[B]. Basically, it doesn't sound as if you plan to spin this engine to the point that the smaller heads will be a hinderance, even if you go with the 383. Hopefully this explains why they size them 180/195 and not 187. It depends on how the engine will be used and how high it will be turned.