gbody 442

Alright so the 442 is back in the garage for the winter and its time to start getting it ready for summer. New springs and shocks are on the way now courtesy of rockauto and the 200r4 trans is awaiting its rebuild. Now I currently have a stock 1972 olds 350 with lightly ported 7a heads. What I plan on for the engine is forged flat tops from summit, edelbrock performer rpm intake, headman headers for a sbo in a gbody, Holley 650 carb, hei dizzy, and I could use some advice from others who have done similar builds on choosing the right high compression cam. Oh yea, i really Wanna throw a hundred shot at it. (just for the cool factor)I've figured with flat tops and 64 cc heads I should be at about 10.5 to 1. No machining will be done if possible. Any thoughts if this combo would be realistic in getting me to 13.5 in a basically stripped 87 442 with 3.73 gears and a 200r4?

z11375ss

13.5 is moving with a 3800 lb car and a small block. It can be done, but perhaps would entail more cost and upgrades than you can afford or want to do.

gbody 442

So even taking the 100 shot into account 13.5 is dreaming a bit? I at least wanna be able to light up 3rd gen z28s and 5.0 fox bodies

z11375ss

I can't say for sure, but it's going to be tough without at least 3.73s in the rear.

380 Racer

Hmmmmm are you sure the 7as are 64 ccs?

bccan

With a well thought out cam you are probably there. Cam has got to walk the line between "big" & "small" so you have good drivability to power relation while paying attention to CR. Be vewy vewy careful w/ flat tops & iron heads (except #8's). I'm a fan of hydraulic roller if you can spend the extra bucks. Might need a pair of drag radials to get outta the hole.

IMO the 100 shot should put you high 12.

coppercutlass

I ran. 13.86 with a 9 to 1 350 that was very mild n a 3500 lb 72 cutlass with 3.73. Gears a 2200 stall in a th400. The 73 short. Block was stone stock and 7 a heads as well just freshened up. 260h comp cam , edel performer intake, 600 cfm carb , full length headers, x pipe , and a short drag radial 275 50 15.


Then I had a 10 to 1 combo with some big valved #6 heads done by rrp, I ran a 280 h cam rpm intake. Same converter same carb and exhaust and all that stuff. I went 13.3's @103 With a converter that was too tight and I could have used a bigger carb im sure if I drove it a little better and with the correct parts like bigger carb and converter I could have seen a 13.0, 12.99. That's been my experience with my combinations.

gbody 442

Well thats what 442.com says but its always a good idea to be sure. I will have them cc'd to be sure.

gbody 442

Piston to valve clearance issues with too much lift/duration? Or something else?

olds 307 and 403

Alot of guys get there with tuning and similar builds to your build. You will probably in the low 10's compression wise. I would put large valves in there and the bowl work to take full advantage of them. Contact Cutlassefi on here. He is a cam expert and engine builder. Alot of us our broke or have limited budgets. I have been pissing around with cheap, corners cut builds with 8 to 1 compression. It just doesn't cut it at my track. You should own that old junk. Unfortunately V6 cars run mid- high 14's these days.

gbody 442

Coppercutlass, the first build you mentioned seems very close to what I plan on running. Very cool that you can get into the high 13s with the block bone stock. Thats whit I would like to do but I do t see any way around the big ol dishes in my pistons. How was drivability around town as this car is also my summertime daily driver

gbody 442

307 and 403, you mention bigger valves but if I really wanted to cant I run a set of 455 heads with flattops and still have decent compression and great breathing engine? Probably wont do it either way but it would be cool.......

coppercutlass

Gbody that engine idled like stock . I could drive everywhere no issues and it ran on 87 octane.

bccan

Re: Valve to piston clearance Q

No problem w/ valve clearance on Olds until you are into very "large" cams. It is a compression ratio/cylinder pressure concern. You have to be careful when using flat tops & older small chamber (appx 70cc & smaller) heads that your cylinder pressure is not too high or engine may require higher octane gas than available at the pump.

You can run into the 10+ range of compression ratio as long as you are using a cam that does not build a lot of cylinder pressure-what I generically refer to as a "big" (long duration) one. Problem is that "big" cams are meant for higher rpm & air flow which will kill low end power & response in a moderate size, stockish small block. 10:1ish compression combined with too "small" a cam will build too much cylinder pressure & you could have trouble w/ preignition/detonation with the 91 or 93 octane pump gas that is commonly available. That is where the line is walked between the CR & cam design. Big & small regarding the cam is relative to the engine displacement & vehicle combo.

Street driven small block w/ middle of the road gearing should be conservative on the cam, especially w/ auto trans.

Other things come into play as far as deck clearance & head gasket volume when tailoring the CR. IMO once you are over actual 9.5:1 w/ iron heads your combo has to be carefully figured & a good tune is required for a safe margin. @ 10+ w/ a smallish cam you are walkin the line. I have owned, seen & read about small blocks on both sides of the line & fixing the problem after it happens can be disproportionately difficult and/or expensive to correct so be careful. There are many on these sites that can offer more technical assistance than I just have but it can act as a primer to help you plan your project

olds 307 and 403

The Procomp or Edelbrock heads would work fine with 10 to 1. Problem is the 77cc chambers, you need about 10cc less=milling needed. Add in a milled intake, electric fuel pump and roller rockers, it adds up. W31 valves are 2"/1.625", you could even go 2.07"/1.625".

Kennybill

I'd put a 403 and drive in and run 12's drive home. Jmo, Ken

coppercutlass

403 is gonna need work and the bottom end is limited according to olds specialist.

gbody 442

Thank you bccan for the thorough explanation. This would be my first legit build and that type of info from ppl who are experienced in this hobby is exactly why I like this site so much. But the other day I was discussing my build plans with my boss's brother ( I work for two brothers who own a heavy machinery repair and rental shop) and he said new pistons with no machining is a halfassed way of doing things and and I would end up loosing my ten to one ratio as the seal between new rings and the unmachined cylinders wouldnt seal right as well as get lit up at the track by ppl who have done their engines "right". Any opinions on this?

gbody 442

If this is the case I do have an extra 1972 olds 350 block so I could save my money to build that one while driving the car with the low comp engine in it.. there always is the ls1 option tho.... hahahaha just playing I wouldnt do that to a real 442

olds 307 and 403

Actually CP has pistons for your motor that only require a block hone, if not too worn. They are light and high quality forged pistons with a modern ring pack, BTR Performance brought them to the market. He has them for $680 with pins and rings. They are a 4.065" vs the stock 4.057" bore. Almost certain some machine will be needed to bring it to 100%. I personally hate having vehicles immobile, I would build the extra 350.

oldsmobiledave

1967 #4 heads are the only factory 64 cc head. The 1972 #7a heads are 68/69 cc heads.


Once again 442 dot com is a good first read but riddled with misinformation.