So is it an otherwise stock 302? The thumpr cams sound good, but they're aren't excellent performers. They like at least 10.5:1 compression as well.

 

I'm going to run the Thumpr in my 1970 302 block. I went with the 279 grind but ordered the 351W version to run that firing order.

 

Do you have any specs on the new engine?..It's kinda hard to make any kind of recommendations knowing nothing about the engine or the rest of the drivetrain?

 

Well I guess I gotta get all the engine and drivetrain info, as far as I know I believe its a stock 302 HO but the truck one as that was the one I believe they were putting in the tbirds. As I've stated before its got a cam in it and I think it may be an edelbrock cam.

 

To each his own, but I do not like the Thumpr cam. I think it makes the engine sound like a 1930's John Deere tractor. As for performance, I think it's a bunch of hype. Just my take.

 

FYI- Sent you a PM

 

A cam's job is to maximize volumetric efficiency (and thus power) in the operating range. Whatever sound that results in is a by product. With these Thumpr cams it seems they turned it around and made the sound dictate the cam timing....

The name(s) are silly too: Big Mutha Thumpr.... like it's a gangsta rap song or something...

 

A cam's job is to maximize volumetric efficiency (and thus power) in the operating range. Whatever sound that results in is a by product. With these Thumpr cams it seems they turned it around and made the sound dictate the cam timing....

The name(s) are silly too: Big Mutha Thumpr.... like it's a gangsta rap song or something...

I agree completely.

 

The Thumpr series actually do make pretty good power in an engine that's set up correctly for one but, they aren't real street friendly unless you plan on spending extra $$ in mods that lesser cams wouldn't need. By lesser I mean lobe seperation angles and intake centerline, (sound) not so much duration numbers. Mods like a "very" loose converter if auto, carb work by someone that knows, (I've yet to see a shelf carb that didn't need idle circuit mods work very well with a Thumpr), low gears, high(er) cr, a top shelf ignition system/etc. The Thumprs were initially designed to produce a very choppy idle for those that want the sound yet still retain some street manners. They're choppy for sure but that's where it ends. Great for a weekender cruise night car but (IMHO) opinion, not a cam you want in a reliable driver. Especially not a basically stocker 302ci driver.

 

I am a bit confused..Are you getting a new longblock or are you getting the one in your car rebuilt?....Or both?

 

Initially, he was going with buying another longblock. Then that company hooked him up with their machinist.

After speaking with said machinist, it was recommended he do a rebuild on his existing 302. The one that he had possible issues with mismatching heads, exhaust manifold problems, etc. However, it seems he's getting a set of new (different) 302 heads from the machinist.

His timeline for rebuilding is in about a month. Now he's trying to figure out what's a good cam to run for the rebuild. Its his daily driver but he wouldn't mind getting a little power and a nice sound while he's at it.

So, he's rebuilding his existing engine and according to him its a stocker 302 from a '86 Thunderbird. He didn't mention any other plans for upgrading anything else.

Sorry for the long post but I like to put things into context. That's how I interpreted his posts.

Also, he did mention:
"I like my current cam, not sure if its gonna work with my engine properly set up cause I feel that the car was running improper due to improperly installing the cam. So it may have flat spots or something."

If it was me, I would not re-use that cam. I don't think anyone so far has suggested that either. However, this leads me to a question.

Is there a way for him to identify what cam he has and just get a new one to throw in his rebuild? Is there like a p/n inscribed on them?

 

I'm curious if he's still doing the transaction through "Super Shop" or just an Outside Machinist? ... How do you know your blocks a good candidate for rebuilding? Does it come with a warranty? ... In fact, I'm curious about the rational used by "Their" Machinist, in why you would be better off letting him rebuild "Your" motor, when they were advertising a Remanufactured motor "In Stock, Ready to go"? (Bait & Switch tactics, or at best miss-leading?)


HERE...... http://sandiego.craigslist.org/csd/pts/2700935474.html


Please Be Careful!

 

I have a the thumper (not the mutha or the big mutha) in my 351w with a set of AFR 185 and a summit stage II intake. Approximate compression is 9.5:1. I love the sound (really love it), but it does not have the best street manners, and creates some really uninspired driving under 1500 RPM. Over 1500 it is a beast, As stated above, it probably needs a higher compression to really come alive

 

Hey yea im getting my current one rebuilt. I called a few machine shops and they all recommended getting my 302 rebuilt. Its funny cause they all say "DO you plan on keeping the car, or selling it?" I say "Oh I plan on keeping it, its my daily driver". They say in that case rebuild your current one.

I was getting it from supershops, and they said they couldnt really guarantee anything since it was a longblock and that there was many other things involved with getting a guarantee on it. So they gave me the number to their machinist. I called him explained everything to him. He said that we should do a complete rebuild top and bottom, that he had some late 302 heads with smaller combustion chambers that would give the motor a higher compression ratio, that If my current heads dont have any cracks on them or what not he will just swap them out at no cost so a trade. He said he would charge me $1,600 to rebuild it and $450 to remove and install. I mean he seems legit...

And when I called supershops they said they didnt have any longblocks ready or anything that they have their machinist make them as there ordered, so thats what I did and I was gonna go give them a deposit on the long block because I wanted it by January. then thats when they gave me the machinist number.

Twinspoppa you got it! haha

Yea for right now im just gonna keep it stock, some time in the next few years change out the tranny for an AOD, rear end gears to 3.55, upgrade to the AFR 165 heads, some dougs headers...

Right now just stock, but more than happy to get a nice cam. Beechkid PM about some good cams which I will most definantly check out and consider.

Do you guys have a good recommendation for a nice beefy sounding cam? I got some dual flowmasters and well, I just want it to sound like the pony car it is!

 

Hey yea im getting my current one rebuilt. I called a few machine shops and they all recommended getting my 302 rebuilt. Its funny cause they all say "DO you plan on keeping the car, or selling it?" I say "Oh I plan on keeping it, its my daily driver". They say in that case rebuild your current one.

I was getting it from supershops, and they said they couldnt really guarantee anything since it was a longblock and that there was many other things involved with getting a guarantee on it.....

And when I called supershops they said they didnt have any longblocks ready or anything that they have their machinist make them as there ordered.....

Fraudulent Ad Here.......http://sandiego.craigslist.org/csd/pts/2700935474.html


WOW.... Sorry for the recommendation! (Supershops) What a bunch of Liars! Did you ask them what they meant by "1 year warranty/ in stock, ready to go!" ? Anyways, I wouldn't want anything to do with them after that!....

I'm still a little concerned about all the advice you're receiving about it being best to rebuild Your motor? Without the block being internally inspected, and without knowing it's history, it's truly impossible to tell if it's a good candidate. I can feasibly see that this rebuild deal could go sideways on you, and end up escalating past the original price. I think you should go with a reputable Long block, where your price is set in stone!

Again, Good Luck with your choices

 

I'm curious. Did you happen to ask the machinist, that's rebuilding your engine, what he would recommend for a cam?

 

I hope you aren't getting taken for a ride here....I would watch this "rebuild" very carefully...Ask the machinest what heads he is putting on your engine?.Late model heads don't exactly have small chambers for high compression..Post up everything he tells you here in case he is feeding you a bunch of crap...
The cam in your engine could be measured by the machinest to see if its in good shape and whether it would be a good candidate to reuse in the rebuilt engine..

 

I've never seen a better candidate for a crate motor...

I've had luck with www.jasperengines.com for daily driver purposes. I know they will also do some performance mods if you contact them.

 

Yea the machinists said he had 302 heads from the 60s to put on the engine. Well my friend owned the car for 4 years and he said he got the motor rebuilt twice. The first time he over heated blew one of the gaskets and I think warped the head. So he took it to a mechanic who really screwed up the motor, all he did was change out the gasket and slap on a 289 head from their garage junkyard. 2 years later car started acting up again people fed him crap and he got the motor rebuilt again. I think they just changes out all the gaskets, left the miss matched heads on, maybe even wrong cam, no new water pump, oil pump, or any if needed replacements like pistons it what not. So the motor with bad parts in it and an untuned carb has now died haha

The machinist told me he would do a complete rebuild, everything. But now... It sounds like I should be cautious of this rebuild?

As I mentioned before oreilly autoparts has longblocks. Those anygood? Also ill take a look at jasper!

 

What you are watching out for with previously rebuilt engines is that the block has been overbored too many times..In your case it doesn't really sound like that is the case..Changing a headgasket and a installing a different head is not an "engine rebuild" it is a repair.....Same with changing out gaskets and installing a few new "bolt ons"...That is not a rebuild..My opinion of a rebuilt engine is one that has been returned to factory or at least new specs...This would include..
Hot tanking and inspecting the block for any cracks or damage...
Decking the block if necessary to true it..(headgasket surfaces)
Boring the cylinders oversized (with torque plates) and installing new pistons and rings..
Machining/polishing the crankshaft and installing new bearings..
Resizing connecting rods..
balancing is not absolutely necessary on a stock type motor but a nice option..
The cylinder heads would be resurfaced and rebuilt with new guides and seals and springs..
Valve seats reground and new or remachined valves installed...
New camshaft and lifters and bearings.
New double roller timing set
New oil pump..
I probably forgot a few things but that will give you a general idea of what a "rebuilt" engine should have...You really won't know the condition of your engine without tearing it down and inspecting it..

 

Anything off the shelf to make the engine "sound beefy" is going to require you install threaded rocker arm studs in the heads, plus with the stock intake and heads just isnt going to act great for you. Also, the cam overlap that gives you the lumpy idle would require more compression to run right. I'd just do a modest cam upgrade to like a Comp Cams High Energy 260H cam. It will give you a little lump.

As far as the rebuild you are doing it doesnt sound like the guy will be doing much if he is going to machine and build the engine for $1600. A proper machining job along with balancing the rotating assembly is going to cost around $800 on average just by its self. Just sounds like new rings, bearings and seals to me. If you plan on doing a performance build in the future I'd recommend upgrading your pistons to a flat top hypereutectic piston and making some upgrades to the stock rods;at least add ARP rod bolts. And get the rotating assembly balanced. Its well worth it. Just make sure you know everything you are getting done during the rebuild and what you aren't.

 

Yea I completly agree frdnut, I don't believe its ever had a true rebuild. So I don't imagine that its been bored out too much. The guy that did the head swap told me that's all he. The other guys probably just changed out the gaskets, seals, etc... So I think my motor is still rebuildable. I've been recommended more than once to this local place by a few mechanics who drag race. I hear these guys are great machinist. The only thing then is I would need to get new heads for them to put on so they don't rebuild it with the wrong heads. They told me $1,100 to rebuild the motor and about another grand to remove and install. That seems to be the average price around town. So that would leave me needing new heads. Those edelbrock e street heads aren't any good huh? Is live the afrs but dude I need my car haha

 

I also called oreillys and they said powertorque builds there reman engines. I bet my block is good its maybe had 1 good rebuild. Seeing its from 86. Chances are it was rebuilt around 96. Then around 2005 is when my friend got jipped and had it "rebuilt" but it just had the head swapped. And then 2 yeas later another horrible rebuild.

 

The sound you hear of a lopey, rumbly cam are the valve events on the exhaust side. That's why those Thumpr cams have such a long exhaust duration. And because of that, high compression is recommended due to the pressure being bled off from the longer duration. Of all the high performance, and all the custom cam specs I've seen posted by people, including some of my own, I have never seen cam specs like those in Thumpr cams. And there is a reason for that...

Someone mentioned the name "Big Mutha Thumpr" as sounding 'gangsta'. Well, I read they got the name from a customer asking Comp to build them a cam that will 'make that motha thump!' and from there the name was born.

And as 6t9mach pointed out, your are going to do other somewhat costly mods to be able to run that kind of cam if you were dead set on it.

Chaz

 

yea im not dead set on it.... I just wanted a nice chugging cam. more importantly though, I want a proper running engine.