fofotoo

Hello All!
First let me provide the details. 400 E block, variable pitch TH400 and standard 3.08 open carrier rearend. The engine was professionally rebuilt using egge components. Comp Cams with .474 lift, 232/241 @.50 duration. Edelbrock Performer intake, HEI distributor and Holley 670 Street Avenger. Stock exhaust manifolds, full length 2.5" exhaust with H pipe, flowmaster mufflers.
Based on my research on this site, I'm pretty sure I'm going to have to recurve the timing using an adjustable vacuum advance kit like a Crane kit. I'm also thinking I don't have enough carb and I haven't heard anything good about the Street Avenger carbs.
I've been tinkering with cars my whole life, but I have no experience with a non-stock configuration like this. Any advice or opinions are greatly appreciated!
Thanks, Mike C.

oldcutlass

Mike, %^%9 is not a very good description. Can you explain in details that we can troubleshoot? Also include things you tried. Also which Egge pistons did they use?


The Street Avenger carb's are fine.

Oldsmaniac

The stock pistons EGGE sells for the E block are flat top pistons like factory. I used them in my stock 400 build. No complaints and engine runs well and strong with point ignition, quadrajet carb and stock intake and exhaust. I used the repro 67 W30 cam and my car has the 390 gear and is a stick. I am very pleased with the way it runs. Yes give more details why you think it runs like crap.

fofotoo

Sorry frustration got the best of me! It bogs off the line, bogs going from cruise to wot. It idles fair in park (fair amount of cam lope, but ok), but very little vacuum when idling in gear. My vacuum gauge shows around 5 inches of vacuum idling in gear. I've adjusted the idle screws on the carb to give me the most vacuum at idle.

Timing - I've tried setting initial timing at 14 and at 16 and haven't had much if any change. I'll admit I wasn't aware of the proper procedure to check mechanical and total timing until recently and it's been way too cold to get out in the garage. That will be my next step when the weather permits.

Carb - I've changed the power valve to a 3.5, I've tried several different jet combinations, several different vaccum secondary springs. I haven't tried a different accelerator pump or squirters. Those were my next steps, but I've kinda' given up on the street avenger to be honest.

oldcutlass

Have you checked for vacuum leaks, your vacuum is awfully low. Have you tried changing your secondary springs around, sounds like it's opening too soon? Yes, timing is crucial, I would reexamine that when the temps get warmer. Also do you have a full 12v at the HEI, no resistor wire?

Oldsmaniac

You may want to review cam ranges specified by manufacturer as far as rear gear ratio and operating range RPM. A 308 gear is a little light. The 670 carb is big enough but it has to be right to give proper performance.

Mikes442

It sounds like a problem I had with my E 400 w/W30 cam. It was a vacuum leak because of a bolt on the intake(stock). Put a bolt in and a very big difference. Woke up the performance big time. Check and see if by chance you are using the right carb gasket.
Mike

fofotoo

Thanks for the quick replies!!

Oldcutlass - I haven't checked for vacuum leaks! I'll get a can of carb cleaner and see what I can find. I have tried every seconday spring in the kit. I think I got the best open rate with the black spring, but don't quote me on that, it was back in the summer. I do have keyed 12 volts at the distributor.

Oldsmaniac - I would love to have more gear! Is a 323 as far as I can go in that diff housing?

Mikes442 - I've got a square bore carb gasket under that carb. No spacer...no room. I had to go with a low profile air filter as it is.

Oldsmaniac

I believe so. It is the carrier that needs to be swapped for greater numbered gears than 3.23. In 67 though 2 different rears were used for the most part the BOP 8.2 with 10 bolt cover and the Olds rear with the 12 bolt cover. I think some Canadian cars got the Chev 12 bolt.

Koda

In the 67 year of the w-30, did they not use metering rods and instead used the 2 barrel jets with no rods to avoid bog from low vacuum/low power piston springs like they did in some other years? Reason I am wondering is what else needs to be done to the engine if a w-30 spec cam is introduced into a 67 442 to make it happen. My application is stock quadrajet, but FoFo's aftermarket carb and mine could probably benefit from the same answers.

Octania

Your symptoms sound like my 403 from a while back.
~10:1 compression with #6 heads
Comp cams 280H ?? cam
HEI
77 Toro QJet
Computer does nothing for the engine anymore


Cured by tailoring the spark curve
the end result was
dist'r vacuum to intake, not carb, for full VA at idle but not while cranking
VA travel limited to ~10-11 degrees using adj. unit
MA travel also changed, it was increased I believe.
timing at idle, with VA in effect ended up WAY up there like 20 degrees, but with that setup, the vacuum was OK at idle, not 5", which opens the power piston... the throttle response was vastly improved, and the overheating at idle went away.

Oldsmaniac

I am not sure about the carb for the W30 but I have not heard that before and do not think it is true. The W30 cam was designed for a 355 or higher numerically gear. It was designed for cold air or OAI and headers/free flowing exhaust.

Koda

Oh, rest assured, it did happen, in 70 at least. That's why I was asking if it happened in 67. My information is usually pretty good, and I'm always sure to state whether or not I'm sure of something.

Here's a thread from a few years ago on the subject.

https://classicoldsmobile.com/forums...-w30-qjet.html

Kennybill

That's a 39 degree camshaft engine, I believe. Look at your cam card. I read about a 66 Toronado that had similar symptoms when a 45 degree was installed. It's probably not but worth checking. Ken

Koda

I have done some perusing. While the w-30 did receive a separate Quadrajet in 70 (actually two, depending on trans, per that above thread), the 67 442 did not.

67 CSM calls for three quadrajets for the 400 block. 7027156, 157, and 032. Those were, respectively, all other applications, AIR regardless of CCC, and non-AIR CCC. Nothing in regards to trans or hi-po options. So, that answers that.

On another note, I can't recall if limited slip differential was standard on 442. He may have a 3.08 posi rear end, I think open was code SC and posi was code SD. Before you go to more gear, make sure that's what you want. I like a highway brawler more than a traffic light to traffic light dragster myself, 3.08 is just fine for me, and fuel economy is awful already.

Fun71

This likely won't do much for your current issue, but when you get around to working on the total timing be aware that most HEIs are set up differently than the earlier points distributors. They typically have ~14º mechanical advance so the initial has to be set to ~20º in order to get the total ~34º. The points distributors had ~24º mechanical so the initial was ~10 to get the same 34º total.

You can either leave the HEI as-is (which is what I did) or use a Moroso HEI advance curve kit to change the mechanical to 24º to match the points and allow the lower initial setting. I liked the higher initial as it gave a stronger and steadier idle vacuum reading.

fofotoo

Octanania - your timing description more or less describes what I was anticipating, but I'm curious about the initial or (idle timing) being at 20 degrees. I assume you are talking about it being at 20 with the vacuum source being disconnected from the distributor. How does the car turnover when starting? My stock starter struggles at the current 16 degree setting.

You also mentioned that you were running the quadrajet from a toronado. I'm also leaning toward going back to a quadrajet myself. I'm thinking about having SMI build one for me. Is your quadrajet stock or modified to support your cam and compression ratio?

Fun71

My HEI is set at 18º initial and the engine turns over fairly easily except when it is very hot. I put 1 gauge starter cables on long ago to help with hot start issues (before the timing increase).

One trick you can do is install a toggle switch in the 12 Volt feed to the HEI. Turn the switch OFF, which will allow the engine to crank very easily, start cranking the engine, and while it's spinning turn the switch ON.
If you hide the switch it can also act as an ignition kill for theft deterrent.