[weedy64]

I am re-assembling my old 327 I built as a kid with my own kid for his little truck. It is a .060 over 327 with 68cc "462" iron heads, forged crank, polished rods, 11:1 forged speed pro pistons, hv pump. Edelbrock torker manifold with edelbrock 625 carb an MSD HEI unit. The engine was line bored and balanced 20yrs ago. The engine was stored in less than favourable conditions but it is not really worn (20000mi) so a light hone, a cleanup and bearings, rings and a cam was all we thought it required to be solid. I recognize the heads could be better but they are paid for so...

It would appear that I didn't know everything when I built this as a teenager. As we assembled it now I notice that the pistons are .035 down the hole so even with .018 steel shims I have the quench area is not ideal. The block has never been decked as the id numbers are clearly readable. Should we zero deck it and run a .040 Felpro MLS or deck it .013 and carry on with the shims or ?????.

Cam selection???? we were thinking a Comp 280H hydraulic, comments. We have magnum pro 1.6 full roller rockers to go with it.

Truck: C10 shortbox with T350c going to a 700R4, Rearend is a 3.08 going to a 3.73 or 4.10 posi (we have both) Rad - we have one from a 6.2 diesel so cooling should not be a problem. Did I miss any applicable info?

Advice please.


Glenn

[F-BIRD'88]

You are going to want no less than a 3000 stall converter for the 280H cam in a 327. and at least 4.10's

[DoubleVision]

If your truly running 11:1 compression you`ll have to run race gas. It`ll detonate itself to death on pump gas unless you really slow down the spark timing.

[oldbogie]

Originally Posted by weedy64

I am re-assembling my old 327 I built as a kid with my own kid for his little truck. It is a .060 over 327 with 68cc "462" iron heads, forged crank, polished rods, 11:1 forged speed pro pistons, hv pump. Edelbrock torker manifold with edelbrock 625 carb an MSD HEI unit. The engine was line bored and balanced 20yrs ago. The engine was stored in less than favourable conditions but it is not really worn (20000mi) so a light hone, a cleanup and bearings, rings and a cam was all we thought it required to be solid. I recognize the heads could be better but they are paid for so...

It would appear that I didn't know everything when I built this as a teenager. As we assembled it now I notice that the pistons are .035 down the hole so even with .018 steel shims I have the quench area is not ideal. The block has never been decked as the id numbers are clearly readable. Should we zero deck it and run a .040 Felpro MLS or deck it .013 and carry on with the shims or ?????.

Cam selection???? we were thinking a Comp 280H hydraulic, comments. We have magnum pro 1.6 full roller rockers to go with it.

Truck: C10 shortbox with T350c going to a 700R4, Rearend is a 3.08 going to a 3.73 or 4.10 posi (we have both) Rad - we have one from a 6.2 diesel so cooling should not be a problem. Did I miss any applicable info?

Advice please.


Glenn

You put in rebuilder pistons with a lower than stock 1.56 inch crown height. These are made with the assumption that rebuilt blocks are all zero decked. From where you're at zero decking the block would restore the compression and make it controllable with gasket thickness, this would also restore the squish quench clearance as well.

The 462 heads would be fine if leaded fuels were still available, their big problem is soft valve seats which won't wear long with todays unleaded fuel, especially with fuels that have alcohol in them. If I was going to put any money into this engine it would be heads. Frankly, there is no better deal on the planet than GMPP Vortecs, a decent price and a 40 hp gain with hard seats. Even with a Vortec intake the cost throw in, it's a less route than aftermarket heads such as the World S/Rs or Dart Iron Eagles keeping your current intake. Plus you can find rebuilt Vortecs all over EBay for the same or less than the cost of a valve job on your old 462s. The Vortec fast burn chamber is much more more tolerant of high compression and/or excessive squish/quench distance than your current heads adding yet another benefit. But their small chambers with your high comp pistons would get over 11 to 1 so to compensate you could forgo decking the block and use the head gasket to control ultimate compression and get most, if not all, the benefits these modern heads offer and skip the cost of decking the block.

Bogie

[techinspector1]

At 11:1, in my opinion, you'll need to use a cam more like a 305H and at least a 3.5K stall converter.

In this fuel octane climate, I wouldn't build the motor at much over 10:1, while cutting for a zero deck and 0.040" gasket. I wouldn't use shims if I could cut for zero and 0.040" MLS.

Personally, I would go with 10.05:1 pistons like these....
http://kb-silvolite.com/performance....etails&P_id=45
I figured the c.r. with 689.5cc's in the cylinder, 68cc's in the chamber, -.5cc's in the piston, zero deck and 8.65cc's in a 4.100" x 0.040" gasket. The stack with these parts would be 9.003". A 280H (min.2.5K stall) or 286H (min. 2.8K stall) cam could then be used effectively. Further, I would use a dual-plane, high-rise intake manifold such as a RPM or Stealth and 1 5/8" long tube headers.

There will surely be other posters with alternate opinions, but that would be the way I would do it. Also, I wouldn't use any deeper gear than a 3.73 with a 700R4. First gear will be 11.45:1. Depends on the cam though. The bugaboo with the 700R4 is the rpm drop on the 1-2 shift. If you gear short for a relatively small motor like this, then first gear becomes almost unuseable. On the other hand, with a 0.7 4th gear, you need a deeper gear, so it's a difficult choice.

Edit: Everybody answered while I was still typing.

[weedy64]

Thank you for your responses.

I think maybe 11:1 statement may have been in error or at least applicable to 58cc chambers. I cannot find the specs for 7002p speed pros so I will grease a piston and drop it .200" in a cylinder to accurately measure the dome volume and report back. I seem to remember my actual CR ~10 and not requiring premium but hell that was 25 yrs ago.

My pistons/cylinders are in good shape so I don't think I want to change them unless necessary. My heads although not optimum do not require anything other than seals so I will run them as is, or until the seats start to leak. In BC ethanol fuel is not that prevalent or maybe they just don't identify it, I don't know, but I avoid ethanol blended fuel in general. If we have to spend money later on heads then vortecs or aluminiums or others will be part of the decision.

It looks like our cam desires are maybe a bit aggressive if we need those kind of stall speeds converters. I would like to limit stall to 2500 or so after we change out the 350C. We just have to have it sound mean. I agree a modern dual plane would be better, but we don't have one right now. The Torker is a least better than the old offy dual plane that we have, the ports are split horizontally at the heads. We don't have out hearts set on the 700R4, it is just a thought. The kid thinks he wants to convert to a 4-5 speed manual, I think shifting gears in a truck will get old fast....but I am already old. So far we haven't spent much other than bearings, rings, gaskets, we are just researching a little before carrying on.

Thanks again to those that responded and those that are think about it.

Glenn

[F-BIRD'88]

For a 2500 stall use a Isky #201271 270 Mega-cam install 4deg advance on 104in C/L.
just right with 1.6 rockers. Ok with the 700r4 just be sure to use the 4.3V6 S-10, corvette, iroc high stall (2200) converter minimum. The other factory bread and butter 700r4 converters are too low stall.

[OLNOLAN]

Man you didn't slip in my shop a swipe my old 327 did you? It sounds like a carbon copy of one the one I've got. I thought I'd throw my two cents in here. The pistons you've got in it are actually about 9.75cr with the 68 cc heads. 58cc=11.04, 68cc=9.77, 72cc=9.34.This based on your .035 in the hole/ with .040 gaskets. Here's my thoughts, some of which you have already been advised;
1) The 462 heads are antiques, I freshened mine in the early 80's(guides,valves,pc seals) but with no lead in the gas, they went away fast(seats&guides). The vortecs suggested are very reasonably priced. Summit has a 67cc chamber set which will put you in the 9.8:1 cr range.$649 for a pair. http://www.summitracing.com/parts/SUM-151124/ Use the .040 felpro's.
2) I wouldn't get too bent on trying to correct the quench, just run it. I don't think you'll be giving up much hp.
3) You'll need a intake, Edelbrock perf RPM/vortec 7116 $187.95
4) I'd go with a set of .065 rings and file fit them.
5) I've run a 268,a 288 and a 300 cam in mine. Knowing the characteristics of those, the Isky that was recommended sounds like a good choice. With a 1.6 rocker you should be okay(the summit vortecs are set up for .525 lift) Make sure to check P/V,guide seal,coil bind clearances. Especially the p/v clearance with dome pistons and a cam with tight LSA. It should have plenty, but check it.(**it happens).
Let us know how it turns out, whatever you decide. olnolan
P.S.-I felt compelled to give credits to my old friend who originally built the engine because he recently passed away. Original setup was 58cc heads, the big 300 degree cam with the old crane triple springs. It was a quick reving, high rev(7000+)with4.56/t400/elcamino it was a stoplight bandit. It was later detuned due to daily use/nolead high priced gas w/no octane.

[cobalt327]

Originally Posted by weedy64

it is not really worn (20000mi) so a light hone, a cleanup and bearings, rings and a cam was all we thought it required to be solid. I recognize the heads could be better but they are paid for so...

Don't fret over the deck height.

The least expensive way is to go w/the thinnest composition or a Mr-Gasket #1130, which is 0.018”- 0.020” compressed thickness steel shim embossed w/coating. Using a non-coated steel shim on used surfaces is not a good idea, IMO.

Then reuse all of the parts already in the engine now. The quench won't be ideal, but not terrible by any means, either.

Base your cam selection on the actual CR. Don't give away anything you don't have to timing-wise, either. There's no point in building something w/so much CR or not enough cam that you have to run 28 degrees (for instance) total timing- you will have given back all the HP that you just tried to make just to keep it from detonating.

Also keep in mind that over-camming the engine in order to "bleed down" the CR can come back to haunt you when the engine is at its torque peak. There, it'll be making the best VE and can be susceptible to detonation.

It is much better to correctly match the components before hand, than to attempt to crutch things up down the road.

[454C10]

I wouldn't worry about the deck height either. Just use a thinner head gasket and call it good.

A 268H or 270H would be a better choice for a truck and 327 combo. Go with a 2500 stall and 4.11 gears.

get a performer rpm intake (not air gap).

use zddp additive with any high performance cam. Todays oil is weak! go to www.zddplus.com and get a case of additive. Use at break in and at each oil change. Will cost $10 more at each oil change.

[techinspector1]

Originally Posted by cobalt327

Also keep in mind that over-camming the engine in order to "bleed down" the CR can come back to haunt you when the engine is at its torque peak. There, it'll be making the best VE and can be susceptible to detonation.

Times 2. I see this every time I run a DynoSim. Cylinder pressure is highest at....or within....500 rpm's of the torque peak, which, depending on the cam timing and heads used, will normally be somewhere around 4500. With any kind of performance exhaust system and no knock sensor, at this rev level, you won't hear the pistons gettin' hammered until it's too late.

[cobalt327]

Originally Posted by techinspector1

Times 2. I see this every time I run a DynoSim. Cylinder pressure is highest at....or within....500 rpm's of the torque peak, which, depending on the cam timing and heads used, will normally be somewhere around 4500. With any kind of performance exhaust system and no knock sensor, at this rev level, you won't hear the pistons gettin' hammered until it's too late.

You are someone (and anyone else who has an idea) who might know- would a knock sensor be capable of dealing w/detonation at 4500 RPM in a case like you've described?

I would tend to believe that the ECM would have enough speed but I've never heard a decisive opinion one way or the other.

[OLNOLAN]

Originally Posted by cobalt327

You are someone (and anyone else who has an idea) who might know- would a knock sensor be capable of dealing w/detonation at 4500 RPM in a case like you've described?

I would tend to believe that the ECM would have enough speed but I've never heard a decisive opinion one way or the other.

Hey Cobalt, I think I understand what you're asking. By no means, I am not a computer person. But I do know about input/output control devices. In Electrical/Instrumentation industry, whether it be primary DCS or auxillary control devices there are different terms used for the systems ability to react to a process variable(input device). It's sometimes referred to as resolution or response time or scan time. If my math is correct, 4500rpm is 75revs/sec or a revolution in 13.33ms. 10,000rpm would be a revolution in 6ms. For todays computers I don't thing a resolution of 6 milliseconds is that fast. They are probably faster than that. A regular poster here (carsavvycook) seems to be pretty sharp on computer controls(ECM & Devices), you might throw the question at him. It is an interesting question.olnolan

[weedy64]

Nolan

Thanks for the 2cents. I think Lous. is a little far away for a midnight run for an old 327. Do you have a big dog? I won't fret as we dropped off the block with a machinist friend yesterday to zer0 deck it, ~$50 so no big deal (before I read more posts here- 454c10,Cobalt). This should make for less variables when swapping heads, and no sealing issues. The kid wants his wheels as his insurance is ticking by so antiques or not we will run our old heads until he earns enough $ to do different or they wear out and run like crap.

I will check p\v clearance and coil bind/seal interference next week, we have a 50 person lamb roast this weekend so little or nothing related to SBC's will transpire.

A 270H or Isky201271 is definitely on the radar.

[OLNOLAN]

Hey Man, With the zero deck and .040 gasket you're looking at about 10.64:1, with .018 about (wow) 11.3:1 Hope ya'll got some good gas up there. I'm gonna throw in a question for the other folks out here if you don't mind Weedy. My old 327 is .060 over also. It was real worn out when I retired it(bad piston slap cold,slight on a couple of cylinders hot). If I took a mind to resurrect it, what do some of the experienced builders out here think I could bore it to. When I worked part time in auto parts years ago, seems like you could get .090's for a 327. How much meat is really in these old blocks?olnolan