Requesting Cam advice for my engine specs
Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
Hi everyone,
I really appreciate all the advice you've given me. I now realize that going with the casting 801 heads from the Chevy 305 is not a good solution and might cause me troubles in the future regarding detonation and so forth.
Therefore I have decided to get some good heads as well. Who cares if I don't get the engine ready as quickly as I planned. I just hate the thought of making a somewhat OK engine and then replacing everything again if I wanted to get a perfect engine. I also think it's better to make it right the first time. Cost is an important factor for me ofcourse since all the prices for the parts are approx. double what you find in Summit pricelist after they arrive here and I pay all the transport + customs fees. I hope I'll still manage to get it ready for the beginning of this Summer.
I've been browsing around for the heads and I want your opinion on these: http://www.summitracing.com/parts/drt-127322
I ran it through the Compression Calculator with the following specs:
Bore 4.030
Stroke 3.48
Head volume 64cc
Effective dome volume +5 cc (should I get different pistons?)
Deck clearance 0.045 in
Gasket 0.040 in
I got the compression ratio 9.37 : 1
I guess I could use some compression like near 10? What do you think is the realistic horsepower I'd get with these heads, a nice flat tappet camshaft and the other stuff I have?
I really appreciate all the advice you've given me. I now realize that going with the casting 801 heads from the Chevy 305 is not a good solution and might cause me troubles in the future regarding detonation and so forth.
Therefore I have decided to get some good heads as well. Who cares if I don't get the engine ready as quickly as I planned. I just hate the thought of making a somewhat OK engine and then replacing everything again if I wanted to get a perfect engine. I also think it's better to make it right the first time. Cost is an important factor for me ofcourse since all the prices for the parts are approx. double what you find in Summit pricelist after they arrive here and I pay all the transport + customs fees. I hope I'll still manage to get it ready for the beginning of this Summer.
I've been browsing around for the heads and I want your opinion on these: http://www.summitracing.com/parts/drt-127322
I ran it through the Compression Calculator with the following specs:
Bore 4.030
Stroke 3.48
Head volume 64cc
Effective dome volume +5 cc (should I get different pistons?)
Deck clearance 0.045 in
Gasket 0.040 in
I got the compression ratio 9.37 : 1
I guess I could use some compression like near 10? What do you think is the realistic horsepower I'd get with these heads, a nice flat tappet camshaft and the other stuff I have?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
If you change to a felpro 1094 gasket you will be at .015 thickness and 4.125 gasket bore. That alone gets you way better quench and bumps compression to 9.9 to 1. I would go with the dart SHP 180 heads. Your existing intake fits them and they are a better size match. Your going with the right approch now match all your build specs with each other and the gearing.
I would think 375 + Hp is a good guess. That is double the L48
I would think 375 + Hp is a good guess. That is double the L48
Last edited by 63mako; Jan 19, 2013 at 01:30 PM.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
With Mako
180 is an excellent sized head for a street 350
Put some Dart 200s on my cammed 350 yrs ago and was real dissapointed. Lost the low end snap which was expected some midrange top only picked up a tad..wasnt thrilled lol. (little did I know they actually poured about 215 thanks Dart)
180 is an excellent sized head for a street 350
Put some Dart 200s on my cammed 350 yrs ago and was real dissapointed. Lost the low end snap which was expected some midrange top only picked up a tad..wasnt thrilled lol. (little did I know they actually poured about 215 thanks Dart)
Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
Thanks for all the tips. Since I have to find affordable ways to get the heads shipped here, I was also scrolling around in eBay. While I found some ProComp head deals, I also found this:
http://www.ebay.com/itm/261097329681...S:1123&vxp=mtr
The guy seems helpful and is able to ship them here for a really nice price. The specs of those heads also seem pretty good. What's your opinion on these? I understand they do not carry a known brand but what that guy has sold so far in eBay has gotten only good feedback.
I have also come to the conclusion that I probably can't stick to the factory flywheel and I also can't get away with the factory bellhousing since I don't want to kill myself or the car or anybody around it in case things go bad. I guess I need to get a Scatter Shield as well. I'd appreciate any help on this taking my combo into consideration...
http://www.ebay.com/itm/261097329681...S:1123&vxp=mtr
The guy seems helpful and is able to ship them here for a really nice price. The specs of those heads also seem pretty good. What's your opinion on these? I understand they do not carry a known brand but what that guy has sold so far in eBay has gotten only good feedback.
I have also come to the conclusion that I probably can't stick to the factory flywheel and I also can't get away with the factory bellhousing since I don't want to kill myself or the car or anybody around it in case things go bad. I guess I need to get a Scatter Shield as well. I'd appreciate any help on this taking my combo into consideration...
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Esp with your shipping cost do yourself a favor buy a good set of heads not that imported pro comp/ebay garbage. Youll regret it if all the pieces even fit together.
AFR Dart Brodix etc all make decent pieces without a lot of issues.
There is a reason they cost more.
AFR Dart Brodix etc all make decent pieces without a lot of issues.
There is a reason they cost more.
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Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
Alright, that's what I also thought - who knows what I'm getting since there's no brand name or anything. I better build it right the first time.
I will try to get the Dart heads in this case.
What do you think - go with hyperexplosive pistons or forged? I looked at these forged pistons: http://www.summitracing.com/parts/sl...make/chevrolet Somebody in hotrodders.com forum mentioned those are crack prone but I wasn't able to find any other topics confirming this statement.
I will try to get the Dart heads in this case.
What do you think - go with hyperexplosive pistons or forged? I looked at these forged pistons: http://www.summitracing.com/parts/sl...make/chevrolet Somebody in hotrodders.com forum mentioned those are crack prone but I wasn't able to find any other topics confirming this statement.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I would not even consider putting an engine together unless I knew the real flow numbers on the heads, this is all about matching parts correctly 
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
Avoid the Pro Comp stuff, Check the flow numbers on the SHPs befor you buy. The best all around street head out there is the AFR 195. Your lookin for the smallest port that will supply the CFM you combo needs. They go for about 1600-1800usd
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
Have your local speed shop help order your heads ,I bought them bare castings and had the speed shop do finish machining, spring and valve selection and assembly. Forged pistons [Mahle] forged crank and rods Callies]. Also have shop prep the block. I had my block 4 bolted splayed caps. With right cam 480+hp at flywheel.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
The Mahle pistons are becoming very popular, they also don't rattle around when cold, unless I can't hear it. But those pistons with a Callies Compstar crank and rods I would defiantly recommend to anyone
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
Heres a good thread on the SHP 200s it was originaly over on yellow bullet but I could not find it. I am a huge Dart fan, the SHP block is gods gift to hot rodding, the shp heads, Im just not feeling it. The profiler 195 is a strong economy head, the AFR is just plane the right stuff but 40-50% more. My experience with ATK has been great, a ported and custom assembled SHP or Profiler will have the advantage of using the exact springs etc you need. There is a AFR dealer on the C4 board here that can help you out with AFRs As usual trying to help a guy out ends up putting a bunch more decisions on his plate.
http://www.chevelles.com/forums/show...dart+shp+heads
oh ya; notice how well the chamber and bowl work bumps up the low lift flow, very important and cheeper than a detailed porting. also pay attention to what valves come in the head, light weight 8mm is good.
http://www.chevelles.com/forums/show...dart+shp+heads
oh ya; notice how well the chamber and bowl work bumps up the low lift flow, very important and cheeper than a detailed porting. also pay attention to what valves come in the head, light weight 8mm is good.
Last edited by Crepitus; Jan 23, 2013 at 03:18 PM.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Noticed those were flowed on a 4.1x bore too initially.
Not exactly impressive #s for dart but I guess for the money if you can do your own porting not bad....if one wasnt happy and had to pay to have it done then not worth it .
Casting quality is usually good and things bolt up right where they should ill give them that much
Not exactly impressive #s for dart but I guess for the money if you can do your own porting not bad....if one wasnt happy and had to pay to have it done then not worth it .
Casting quality is usually good and things bolt up right where they should ill give them that much
Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
I appreciate all the replies! Very useful info. I'm browsing through the Chevelles forum thread also.
I know the AFR's would be the ultimate. Although I'm considering the option it just seems like since it's going to be 2x extra cost after shipping + customs here, I might not work it out since there's so much more stuff I need to order.
If I went with the SHP series, I understand in my case I should better take the 180cc ones. What do you think would be the most aggressive camshaft I could use (flat tappet) and should I go with forged pistons?
I know the AFR's would be the ultimate. Although I'm considering the option it just seems like since it's going to be 2x extra cost after shipping + customs here, I might not work it out since there's so much more stuff I need to order.
If I went with the SHP series, I understand in my case I should better take the 180cc ones. What do you think would be the most aggressive camshaft I could use (flat tappet) and should I go with forged pistons?
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
car gets 2to 3000 miles per season. grocerie store, visiting friends, errands, etc. third year on plugs with no intention of changing them. plug fouling comes from inaccurate carb jetting. in overdrive at 65 rpm is 1650 no hesitations or fouling, engine preforms flawlessly on track or road and in the city.
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
http://www.us.mahle.com/MAHLE_North_...er-Pak-Pistons
quality piston at a decent price, nice modern ring package, doesnt require a lot of skirt clearance. you could save a couple hundred $ with Hypertunies but a good forged piston will tolerate a tuning mistake or over heating much better than any cast / hypertunie piston. These will tolerate N2O nicely as well. Be careful not to scuff up the skirts with mikes or installation. These are available in different bore dia as well as head shape. be sure to get the right dimensions before ordering. We can get that worked out here if you like. they will need to fit the heads / deck / gasket for correct compression and block over bore. I am assuming 5.7 rod and 3.48 stroke
http://www.summitracing.com/parts/ml...make/chevrolet
quality piston at a decent price, nice modern ring package, doesnt require a lot of skirt clearance. you could save a couple hundred $ with Hypertunies but a good forged piston will tolerate a tuning mistake or over heating much better than any cast / hypertunie piston. These will tolerate N2O nicely as well. Be careful not to scuff up the skirts with mikes or installation. These are available in different bore dia as well as head shape. be sure to get the right dimensions before ordering. We can get that worked out here if you like. they will need to fit the heads / deck / gasket for correct compression and block over bore. I am assuming 5.7 rod and 3.48 stroke
http://www.summitracing.com/parts/ml...make/chevrolet
Last edited by Crepitus; Jan 22, 2013 at 06:12 AM.
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
To get serious about head cam compression we need to know a few things;
budget, what parts do you want to reuse? intake carb crank rods ect.
usage; smooth idle? lotsa vacume? girl proof? hp goals? any track use? lotsa hair on fire foot to the floor screamin like a mad man?
Weight probably in the neighborhood of 3400#(stock 75 Vette)
auto or 4 speed? converter stall and rear gear?
header exhaust layout?
fuel quality
budget, what parts do you want to reuse? intake carb crank rods ect.
usage; smooth idle? lotsa vacume? girl proof? hp goals? any track use? lotsa hair on fire foot to the floor screamin like a mad man?
Weight probably in the neighborhood of 3400#(stock 75 Vette)
auto or 4 speed? converter stall and rear gear?
header exhaust layout?
fuel quality
Last edited by Crepitus; Jan 22, 2013 at 06:39 AM.