[25stevem]

Yes!
Even though that 400 was not running the 1.65 rockers to match the intended use of that Cam it should have peaked higher.

Get., I mean the smaller 744 Cam peaker higher then 5K

[Cliff R]

The engine doesn't even sound like it has a "RAIV" cam in it, nor is it making the numbers a RAIV cam will make in a Pontiac 400 build with #48 heads on it.

There are simply a LOT of things amiss with that build, and even with the blurb at the end how they bolted on a Holley and swapped out the points distributor for an HEI and saw improvements, the numbers just aren't there.

I'll add here that the RAIV is really not the best choice for a 400 engine unless you've pretty much patterned it after the original RAII and RAIV engines. Those engines had high compression, and round port heads, plus the factory made sure the cars they went into had pretty tall rear gears.

I've found from building 400's here with "D" port heads, or even KRE aluminum "D" ports that I can make about the same HP with a slightly smaller cam and enjoy more vacuum at idle, improved throttle response, and more power and efficiency in the "normal" driving range. With over 80 degrees of overlap the RAIV cam just bleeds off too much cylinder pressure in 400 builds for street use. It only works OK at 10 to 1 compression, better around 10.5 and starts to shine pretty good up near or just over 11 to 1.

I actually had a customer once have his RAIV engine rebuilt and the "builder" lowered the compression by machining a dish in a TRW forged piston and installing a "modern" lobe profile cam dubbed as having "RAIV specs". Down at 9.5 to 1 it was a complete "turd" even with the "modern" camshaft in it and he ended up having it done again with flat tops, tight squish, real RAIV cam, and closer to 11 to 1 compression. Even clear up there it managed 92-93 octane without issues. That clearly show us how much cylinder pressure you bleed off the RAIV cam in a 400 build.........

[Stan Weiss]

What I heard was Nick was given an engine and parts to change by his customer.

He had to look at the heads to even know which heads they were. He was probable told it was an 041 cam and would not know the difference if it was not

Stan

[Jay S]

Is there someone I have never heard of that has made a qjet work with no secondary metering rods? LOL

Some later Carter carbs have a spray bar/air bleads ( for lack of a better word, Cliff likely knows the correct term) on the leading side of the secondary air door to distribute fuel as the air door opens, instead of metering rods. Maybe someone got the carbs types confused and forgot to put the metering rods in…

I used fast forwarding thru much of the video. But I did catch the part were he said the engine was standard bore yet, had low oil pressure, and was more or less a used engine from one of the owner’s friends. So no big shock it didn’t put up very big dyno numbers. Looked like the owner didn’t give Nick much to work with.


At just over 100 lbs oil pressure we have sheared the timing gear/cam keys. After having a couple of them shear. I get a little nervous when the oil pressure get’s up to 100.

[formula kid]

I don't get it, at 4:55 into the video Nick is heard to say that in 1976 he worked for Pontiac for 5-6 years. You mean to tell me if he worked for Pontiac in that time period, he was not sure what #48 heads were. He also said that the customer wanted these heads because they were from 1969. At that time, he would have run across GTO's and Trans Am's with those heads. Also, why would you test a Pontiac with a chevy quadrajet that you would have no clue what the primary or secondary jets are. You would be much better taking to customers quadrajet
and rebuild it. Sorry this build has many problems. Putting in a oil pump that gets you 100PSI cold nuts. That was the 20W-50 oil and an SD-455 oil pump. With stock weight oil that pump was known to blow oil filters off cold winter starts. When my SD-455 was rebuilt Nunzi switched out the 80 psi spring for a 60psi so I wouldn't have to worry about that problem. Because I was not running the engine to 6,500 rpm.

[25stevem]

Jay you make a great point!

I don’t think I would be going out on limb by saying that I don’t think there is any racing situation where you could get a Q-jet to work with no secondary metering rods in it.

Even if by some form of magic you did I can’t see the biggest needle and seat that could put in that carb keeping up with the fuel demand of those big now rodless holes!

[jhein]

I would not hire him.

[Stan Weiss]

While it may peak @ 5000 RPM it really starts to layover @ 4700 RPM. I cannot believe that the cam the customer gave Nick was a RAIV / 041 cam.

Stan

[Stuart]

Originally Posted by formula kid

I don't get it, at 4:55 into the video Nick is heard to say that in 1976 he worked for Pontiac for 5-6 years.

To be clear, he worked at a Pontiac dealership during that time period, not for corporate Pontiac. As for this particular engine, he didn't build it, it was furnished to him by the owner who supplied the parts; my understanding is those particular cylinder heads were installed to reduce compression. Also, he said at the beginning of the video that the runs would be only done to 5,000rpm, I assume that was at the direction of the owner but don't know that for a fact.

[TCSGTO]

There is no way that was a RAIV cam. It was pulling 17” Hg under 1000 rpm and idled like Catalina wagon.
It’s a video for people who don’t know any better. I still enjoyed it more than a lot of the mindless drivel on YouTube

[25stevem]

A stock RA4 motor with its 1.65 rockers,better heads and intake then D port stuff pulls right up to 5800 and then nose dives from the last dyno sheet of such that I recall seeing.

Can someone confirm me on this recollection please?

[mchell]

Nick’s a trip to watch. I have a hard time criticizing a guy that’s trying…… ran into more issues than he expected and he didn’t cut those out..

In my experience, the dyno operator slash engine builder will generally be of ZERO help if you show up with a qjet. I usually bring a couple of my favorite qjets and a few parts for a session. I also bring another distributor.

[TCSGTO]

Originally Posted by mchell

Nick’s a trip to watch. I have a hard time criticizing a guy that’s trying…… ran into more issues than he expected and he didn’t cut those out..

In my experience, the dyno operator slash engine builder will generally be of ZERO help if you show up with a qjet. I usually bring a couple of my favorite qjets and a few parts for a session. I also bring another distributor.

Yes,exactly. Usually on the internet you plug numbers into a program, throw it together and everything is hunky dory on the 1st try. Real life, at least the one I live in, usually doesn’t work that way.

[jhein]

Nick probably is a super nice guy. No doubt, fun to have a couple beers with.

The build wasn't his, someone gave it to him and said "do your best". Fine.

It's just his approach to the dyno session that's perplexing. I can understand unexpected things happening. But it seems like all/most of the problems he had were things he should have easily anticipated/prepared for.

Also, as far as the cam is concerned, for him to install it properly, wouldn't he have to have the cam card and therefore know if it's a "RAIV" cam or not?

That's fine. It's all for fun.

[Stan Weiss]

Originally Posted by jhein

Nick probably is a super nice guy. No doubt, fun to have a couple beers with.

The build wasn't his, someone gave it to him and said "do your best". Fine.

It's just his approach to the dyno session that's perplexing. I can understand unexpected things happening. But it seems like all/most of the problems he had were things he should have easily anticipated/prepared for.

Also, as far as the cam is concerned, for him to install it properly, wouldn't he have to have the cam card and therefore know if it's a "RAIV" cam or not?

That's fine. It's all for fun.

My take is someone in the shop was given an engine and a cam to install into it. The cam matched the specs on the cam card and all was good. They did their job and may not even know a 066 cam spec from an 041 cam spec.

Stan

[jreynolds]

Originally Posted by Stuart

To be clear, he worked at a Pontiac dealership during that time period, not for corporate Pontiac. As for this particular engine, he didn't build it, it was furnished to him by the owner who supplied the parts; my understanding is those particular cylinder heads were installed to reduce compression. Also, he said at the beginning of the video that the runs would be only done to 5,000rpm, I assume that was at the direction of the owner but don't know that for a fact.

I think he said they changed heads because he wanted it to be correct on the 1969 model car. Which makes sense because they are #48s.

Anyway, I would just expect a #48 headed 400 with an 041, plus headers, to be a pretty stout (assuming flat tops and good tune). Those are big valves and 68-72ish CC chambers depending on where you read it.

[Stan Weiss]

Does anyone have a sound clip of a RAIV running with mufflers? It has been a number of years since I last heard a RAIV with closed exhaust. So maybe my memory is bad. But I remember a RAIV (041 cam) sounding much different at idle.

Stan

[400 Lemans]

Originally Posted by Stan Weiss

Does anyone have a sound clip of a RAIV running with mufflers? It has been a number of years since I last heard a RAIV with closed exhaust. So maybe my memory is bad. But I remember a RAIV (041 cam) sounding much different at idle.

Stan

This one is my favorite.https://www.youtube.com/watch?v=DQtQCFWWBzs

[grandam1979]

Originally Posted by 400 Lemans

This one is my favorite.https://www.youtube.com/watch?v=DQtQCFWWBzs

That does not sound like a ram air IV cam

[25stevem]

As said in post 50, it was pulling 17 hg of vacuum so it can not be RA4 Cam.

If you want to hear a RAIII with near open Exh then go watch the video of the 1970 Humbler where the kid is driving thru a parking lot.