Hi all
I am currently rebuildingmy L48 350 engine for camaro and the engine is now stripped down to the shortblock. The engine is in preaty good shape apart from a badly worn camshaft , 3 lobes had benn worn to a round shape ,. and a very slightly worn crank.
Now the engine is in bits im looking for a rebuild kit to suit my application but before i buy i was hoping to run a few things past you guys.

1. Is it worth regrinding the original crank or would it be worth investing in a new one while the engine is in bits ? as i said its not that bad but not to sure if the stock ones are up to much anyway ?

2. i live in the U.K and have finally found a supplier here that stocks these kits so this is what i'm going for http://www.americanv8engines.co.uk/...e_Rebuild_Kits.
Is this an adequate kit for for a street / strip application. I'm looking to get my motor to about the 330 bhp / 350 lbs torque mark so i need to make sure my bottom end is up to the task , i know its not massive figures but i want to be certain i'm doing it right as i dont plan on dropping the engine again in a hurry.

3. What duration could i go on a cam without making the car undrivable on the road ?

4. One of my biggest aims is to get the CR on my engine up past the 8.1 ratio. Am i right in saying that aftermarket pistons and heads can improve this if so then are the pistons in this kit up to scratch

Many thanks in advance for any help i recieve . Thanks. Craig

 

the link doesn't work for me.

 

so then this is going to be a primarily street driven car? good street manners? 330HP at the crank desired?
no problem. Probably want to do it on a mega low budget due to inflated costs to you (shipping, etc etc.) eh?

i'd turn the crank down, you could get that done locally for.... well, much less then a new cast one, which is all you'd need for your desired power levels. That shop is local to you I assume?

link didn't work for me either.... 'cuz that "..." is actually in the link...

http://www.americanv8engines.co.uk/?..._Rebuild_Kits.

is right?

that should be just fine for ya, 350pounds is $700USD ish? not too bad... If you want a bit of a kick more, i'd recommend trying to get them to substitute in a more agressive cam, but that one should be ok. The pistons in that kit are flat top hypereutetic, that'll give you more compression, and those are just fine for your application.

stock heads staying on the car? or....? (know the casting # on them?) i'd guess more then 64cc, so you won't have the 9.5:1 CR advertised in their kit.

 

Both those cams are old out dated GM 60's era designs made for a 11:1 high compression motor.
The larger .480" lift cam has a rough idle and requires a high stall torque converter as the low end torque is soft.
the .447" ift cam is the old 327-350hp "151 cam"

You can do better with this cam. usually the supplyer of these kits also stocks a selection of Clevite performacne cams that you can substitue in the kit.
There is a better Clevite Cam you should substatue.
Look in the Clevite calalog for the 214-224@.050 .442" .465" 112 LSA angle camshaft. "107/117"
it will have nice strong torque and power from right off idle to 5500rpm with more than enough power. it will idle nicer with more intake vacuum than either of those two choices. It is a better choice. It will work fine with a stock torque converter.
A mid 3.xx up to 4.10 rear gears is best for draging.
The Clevite pn is 229-1988. The Wolverine ( Crane Blue Racer) # is WG1159


What heads (head casting number) is on that motor?Clevite parts and kit info

 

hey f-bird, what would be the difference in the original cam, and that cam you're quoting?

both roughly .44" intake lift, ~220 intake duration.... seems very similar...?

 

The intake duration is much shorter (8 degrees) and more advanced in the motor. in my cam choice resuting in better torque and cylinder pressure thru a wider power band overall. A much better match for 9.5:1 cr.

214@.050 compared to 222@.050. intake duration.

earlier intake closing of 34* BTC compared to 41 BTC for the 327cam.

The WG1159 will flat out out perform the old 327-350hp 306* .447" cam that comes in that kit..
there is anothe simular Clevite engine kit that comes with the right cam. Don't know the kit number.
Makes more low end and mid power with same top end in a 9.5:1 motor.
Its a matter of usable torque. the old 327 cam was good in its day but this one is better for the posters purpose.
the old 327-350hp cam was designed for a corvette with 11:1 compression and a 4speed. It will actually make 350hp when build with all the orignal parts of the 1965 327/350hp L79 combo, but he has neitherr the fuelie heads (461X) or the compression ratio (11:1).
This same cam was used in 1973/4 350 Z28 motors but sucked with 9:1 cr and smogger heads and Qjet carb.
(245hp)

Those kits are available with many different cams but that page only shows two of the chevy kits.
federal Mogul/ Speed Pro and Engine Tech have the same performance engine kits marketed under differnent Brand names.

 

Thanks for that info guys

Sonix the car is mainly going to be street driven with the odd strip run , maybe 3 a year , and your spot on when you mention the inflated prices for parts over here , shipping preaty much kills getting bits,. Once the bottom end is done i will purchasing either later vortec heads or the world sportsman type. I see you mention about the chambers being 64? could you explain what this means and what difference it makes.

F-BIRD'88 thanks for that cam option. I have rang the company who supply the kit and they said they can swap the cam for preaty much what ever i want. I here alot of peaole mention that cams having to much lift for the duration. would i have this problem with your cam choice.

A big thank you again . Craig

 

No this cam is a good overall cam to upgrade a mild motor during a rebuild. the stock valve train can easily handle this cam' s modest lift. GM stock diameter "Z28" hi perf springs are recomended. Speed pro/federal mogul #is vs739R. There is a equivelent Clevite part number that is the same good spring. the GM # ends in 142.

this cam will work well with stock smogger heads and even better with ported stock heads with bigger valves or new vortec heads and manifold.

My car ran 13.0 ets at 104.5MPH wiith this cam and vortec heads on a 350 with 4.10's. gas mileage was good.
Crank gross BHP was 360 to 375. Torque is very strong and smooth. Use a 750cfm carb and a Edelbrock Performer RPM intake if ya can. You can get very close to this power with ported stock heads with 2.02x 1.60 valves.

Some of the stock heads of the era were better than others.
Some can be modified to work pretty good if you're into porting heads and getting dirty.
What heads do you have to work with now? casting ###'s

 

F-BIRD i cant seem to find my casting numbers but im sure they ended with 624 or something like that. I did post my numbers of the cam and heads a while ago and i was told that they were some of the most restrictive heads that GM ever built and that they were not worth a damn.

The engine is a the '79 L48 corvette engine a its meant to be a right smogger so the heads are being replaced with either vortec / world sportsman / edelbrock rpm heads depending on what funds are left over, so i need a cam to work well with aftermarket heads. Basically nothing from the old engine will be left apart from the stock short block which is machined .030" over

 

If you have 624 heads, then I agree. Don't bother with them.

Go with the vortecs and a vortec manifold. I recomend the RPM manifold. They work very well.

What rear gear ratio? what torque converter stall etc.
Any other details.

 

the kit advertised that with those pistons in the kit, and 64cc chambers, you'd see 9.5:1 CR. I *think* the 624's have 76cc, (hence smogger), and would drop your CR. however you aren't considering using those heads, so i'll drop the conversation there.

If you're looking for vortecs or sportsmans, try for 64cc chambers, as that would give you the 9.5:1 CR, which is a good # to have. If you have lower cc heads, (like 58cc's for example), then you'd have a higher CR. I think 9.5:1, is a good choice. Vortecs would work great for you. I don't think you'd be able to find those in the junk yard there, so summit's vortecs might be a good bet.

 

Does the motor need to be bored? If not I would keep the pistons they should be a forged flat top 3.6cc.

GM used those pistons up to 86 in the iron headed TPI vette motors. They also used the 624 heads and a .021 head gasket to get a 9 to 1 compression ratio.

With a 64cc chamber head and a .021 head gasket your looking at around 10.25 compression ratio

I would have the crank turned, have the rod checked out, upgrade rod bolts. 9 times out of 10 that will be the first thing to on a stock short block. So now all you need is rings and bearings, Have the motor honed and new cam bearings. I would also have everything balanced.

For heads you still might be able to pick up a set of ProTopline Heads. Pretty sure they have some remaing stock for not much$$. They have distributors in New Zealand and Australia. Dont know if that will be cheaper for shipping?

 

F-BIRD i have stock gear ratio on my camaro. Also the torque converter is stock. Will the torque converter have to be upgraded ? if so any recomendations. The gear box 700 R4 and although i have never experienced problems i'm worried that when i put it all back together again it might not handle the added power. So i will make a post in the relavent section about beefing it up. Also i point of concern is my driveshaft. Do you know what the stock DS is capable of handling ?

Sonix your right there is no chance of finding anything like vortecs in a scrap yard although i do know of a guy scrapping a 4th gen camaro with a V8 in it. It might be an idea to ask him what heads are on it.

11 Flat yeah the engine does need to be bored and my machinist said that a .030" bore will be fine. The crank is being turned and all rods rings and bearings are being renewed. Basically the only thing from the original engine will be the short block. Never heard of those heads but i will look into them.

 

pro-topline went out of business a little over a year ago and are now owned by a company named RHS.
http//www.racinghead.com
a division of comp cams.
i haven't called them ,but i don't see the vortec replacement heads listed on their website?
might be worth a call though!if you do call them,let us know what you find out!
i have a set and am very impressed with the heads and the priice.
Eric B

 

Don't bother looking for vortec heads in the scrap yard.
Buy new ones, ready to rock. 4th gens did not come with vortec heads. Only 96 and up GM trucks with the L-31 vortec 350 came with vortec heads. only casting numbers are 062 and 906. All others are not GM vortec heads.
These heads will work with the specific cam "out of the box"
any cam with more lift or wanting more rpm will need better valvesprings and guide boss machining.
www.sdpc2000.com is a good source for vortec heads.
They ship world wide. They even have head+ manifold packages.

This set up is mild enough and will work with a stock stall converter and rear gearing. Works better with a moderate stall increase and 3.73/4.10 rear gearing. remeber you still have a 30% overdrive in 4th so you'll still have nice cruising rpm on the hwyway with 3.73 or 4.10 rear gearing.
If you want to change the converter look for a 3000+/- stall in a "lockup converter" for a 700r4. usually it is a 9.5" diameter converter. Cheap modified 12.5" factory converters while having up to 2600stall *but* are not that efficient. If you want a hi stall for a 700r4 get a 9.5" like a Yank or a Vigilante converter.
http://www.converter.com
http://www.converter.cc

A quality hi stall like the yank or vigilante will improve acceleration by about .5 sec over a stock stall converter.
Will need hi traction tires to harness the launch power thou.
If your stock rear gear ratio is less than 3.23:1 now and:
if you have to choose betweem new gears or a new converter go for the gears first. (3.73 or 4.10) Then save for a quality hi stall lock up converter.
You can determine your present rear gearing ratio by checking the RPO codes on your build sheet. (glove box)